views_ui.admin.inc

<?php
/**
 * @file
 * Admin page callbacks for the Views UI module.
 */

/**
 * Create an array of Views admin CSS for adding or attaching.
 *
 * This returns an array of arrays. Each array represents a single
 * file. The array format is:
 * - file: The fully qualified name of the file to send to backdrop_add_css
 * - options: An array of options to pass to backdrop_add_css.
 */
function views_ui_get_admin_css() {
  $module_path = backdrop_get_path('module', 'views_ui');
  $list = array();
  $list[$module_path . '/css/views_ui.admin.css'] = array();
  $list[$module_path . '/css/views_ui.admin.theme.css'] = array();

  // Add in any theme specific CSS files we have
  $themes = list_themes();
  $theme_key = $GLOBALS['theme'];
  while ($theme_key) {
    // Try to find the admin css file for non-core themes.
    $theme_path = backdrop_get_path('theme', $theme_key);
    // First search in the css directory, then in the root folder of the theme.
    if (file_exists($theme_path . "/css/views-admin.$theme_key.css")) {
      $list[$theme_path . "/css/views-admin.$theme_key.css"] = array(
        'group' => CSS_THEME,
      );
    }
    elseif (file_exists($theme_path . "/views-admin.$theme_key.css")) {
      $list[$theme_path . "/views-admin.$theme_key.css"] = array(
        'group' => CSS_THEME,
      );
    }
    $theme_key = isset($themes[$theme_key]->base_theme) ? $themes[$theme_key]->base_theme : '';
  }

  return $list;
}

/**
 * Adds standard Views administration CSS to the current page.
 */
function views_ui_add_admin_css() {
  foreach (views_ui_get_admin_css() as $file => $options) {
    backdrop_add_css($file, $options);
  }
}

/**
 * Returns the results of the live preview.
 */
function views_ui_preview($view, $display_id, $args = array()) {
  // When this function is invoked as a page callback, each Views argument is
  // passed separately.
  if (!is_array($args)) {
    $args = array_slice(func_get_args(), 2);
  }

  // Save $_GET['q'] so it can be restored before returning from this function.
  $q = $_GET['q'];

  // Determine where the query and performance statistics should be output.
  $config = config('views_ui.settings');
  $show_query = $config->get('show_sql_query');
  $show_info = $config->get('show_preview_information');
  $show_location = $config->get('show_sql_query_where');

  $show_stats = $config->get('show_performance_statistics');
  if ($show_stats) {
    $show_stats = $config->get('show_sql_query_where');
  }

  $combined = $show_query && $show_stats;

  $rows = array('query' => array(), 'statistics' => array());
  $output = '';

  $errors = $view->validate();
  if ($errors === TRUE) {
    $view->ajax = TRUE;
    $view->live_preview = TRUE;
    $view->views_ui_context = TRUE;

    // AJAX happens via $_POST but everything expects exposed data to
    // be in GET. Copy stuff but remove ajax-framework specific keys.
    // If we're clicking on links in a preview, though, we could actually
    // still have some in $_GET, so we use $_REQUEST to ensure we get it all.
    $exposed_input = $_REQUEST;
    foreach (array('view_name', 'view_display_id', 'view_args', 'view_path', 'view_dom_id', 'pager_element', 'view_base_path', 'ajax_html_ids', 'ajax_page_state', 'form_id', 'form_build_id', 'form_token') as $key) {
      if (isset($exposed_input[$key])) {
        unset($exposed_input[$key]);
      }
    }

    $view->set_exposed_input($exposed_input);


    if (!$view->set_display($display_id)) {
      return t('Invalid display id @display', array('@display' => $display_id));
    }

    $view->set_arguments($args);

    // Store the current view URL for later use:
    if ($view->display_handler->get_option('path')) {
      $path = $view->get_url();
    }

    // Make view links come back to preview.
    $view->override_path = 'admin/structure/views/nojs/preview/' . $view->name . '/' . $display_id;

    // Also override $_GET['q'] so we get the pager.
    $original_path = current_path();
    $_GET['q'] = $view->override_path;
    if ($args) {
      $_GET['q'] .= '/' . implode('/', $args);
    }

    // Suppress contextual links of entities within the result set during a
    // Preview.
    // @todo We'll want to add contextual links specific to configuring the View
    // so the suppression may need to be moved deeper into the Preview pipeline.
    views_ui_contextual_links_suppress_push();
    $preview = $view->preview($display_id, $args);
    views_ui_contextual_links_suppress_pop();

    // Reset variables.
    unset($view->override_path);
    $_GET['q'] = $original_path;

    // Prepare the query information and statistics to show either above or
    // below the view preview.
    if ($show_info || $show_query || $show_stats) {
      // Get information from the preview for display.
      if (!empty($view->build_info['query'])) {
        if ($show_query) {
          $query = $view->build_info['query'];
          // Only the sql default class has a method getArguments.
          $quoted = array();

          if (get_class($view->query) == 'views_plugin_query_default') {
            $quoted = $query->getArguments();
            $connection = Database::getConnection();
            foreach ($quoted as $key => $val) {
              if (is_array($val)) {
                $quoted[$key] = implode(', ', array_map(array($connection, 'quote'), $val));
              }
              else {
                $quoted[$key] = $connection->quote($val);
              }
            }
          }
          $rows['query'][] = array('<strong>' . t('Query') . '</strong>', '<pre>' . check_plain(strtr($query, $quoted)) . '</pre>');
          if (!empty($view->additional_queries)) {
            $queries = '<strong>' . t('These queries were run during view rendering:') . '</strong>';
            foreach ($view->additional_queries as $query) {
              if ($queries) {
                $queries .= "\n";
              }
              $queries .= t('[@time ms]', array('@time' => intval($query[1] * 100000) / 100)) . ' ' . $query[0];
            }

            $rows['query'][] = array('<strong>' . t('Other queries') . '</strong>', '<pre>' . $queries . '</pre>');
          }
        }
        if ($show_info) {
          $rows['query'][] = array('<strong>' . t('Title') . '</strong>', filter_xss_admin($view->get_title()));
          if (isset($path)) {
            $path = l($path, $path);
          }
          else {
            $path = t('This display has no path.');
          }
          $rows['query'][] = array('<strong>' . t('Path') . '</strong>', $path);
        }

        if ($show_stats) {
          $rows['statistics'][] = array('<strong>' . t('Query build time') . '</strong>', t('@time ms', array('@time' => intval($view->build_time * 100000) / 100)));
          $rows['statistics'][] = array('<strong>' . t('Query execute time') . '</strong>', t('@time ms', array('@time' => intval($view->execute_time * 100000) / 100)));
          $rows['statistics'][] = array('<strong>' . t('View render time') . '</strong>', t('@time ms', array('@time' => intval($view->render_time * 100000) / 100)));

        }
        backdrop_alter('views_preview_info', $rows, $view);
      }
      else {
        // No query was run. Display that information in place of either the
        // query or the performance statistics, whichever comes first.
        if ($combined || ($show_location === 'above')) {
          $rows['query'] = array(array('<strong>' . t('Query') . '</strong>', t('No query was run')));
        }
        else {
          $rows['statistics'] = array(array('<strong>' . t('Query') . '</strong>', t('No query was run')));
        }
      }
    }
  }
  else {
    foreach ($errors as $error) {
      backdrop_set_message($error, 'error');
    }
    $preview = t('Unable to preview due to validation errors.');
  }

  // Assemble the preview, the query info, and the query statistics in the
  // requested order.
  if ($show_location === 'above') {
    if ($combined) {
      $output .= '<div class="views-query-info">' . theme('table', array('rows' => array_merge($rows['query'], $rows['statistics']))) . '</div>';
    }
    else {
      $output .= '<div class="views-query-info">' . theme('table', array('rows' => $rows['query'])) . '</div>';
    }
  }
  elseif ($show_stats === 'above') {
    $output .= '<div class="views-query-info">' . theme('table', array('rows' => $rows['statistics'])) . '</div>';
  }

  $output .= $preview;

  if ($show_location === 'below') {
    if ($combined) {
      $output .= '<div class="views-query-info">' . theme('table', array('rows' => array_merge($rows['query'], $rows['statistics']))) . '</div>';
    }
    else {
      $output .= '<div class="views-query-info">' . theme('table', array('rows' => $rows['query'])) . '</div>';
    }
  }
  elseif ($show_stats === 'below') {
    $output .= '<div class="views-query-info">' . theme('table', array('rows' => $rows['statistics'])) . '</div>';
  }

  $_GET['q'] = $q;
  return $output;
}

/**
 * Page callback at admin/build/views to list all available views.
 */
function views_ui_list_page() {
  views_ui_add_admin_css();

  $header = array(
    array('data' => t('Name'), 'class' => array('views-ui-name')),
    array('data' => t('Description'), 'class' => array('views-ui-description')),
    array('data' => t('Displays'), 'class' => array('views-ui-displays')),
    array('data' => t('Storage state'), 'class' => array('views-ui-storage')),
    array('data' => t('Operations'), 'class' => array('views-ui-operations')),
  );

  // Get and sort enabled views.
  $enabled = views_get_enabled_views();
  $enabled_sorted = array();
  foreach ($enabled as $key => $view) {
    $enabled_sorted[$key] = $view->human_name;
  }
  natcasesort($enabled_sorted);

  // Get and sort disabled views.
  $disabled = views_get_disabled_views();
  $disabled_sorted = array();
  foreach ($disabled as $key => $view) {
    $disabled_sorted[$key] = $view->human_name;
  }
  natcasesort($disabled_sorted);

  // Get complete set of views.
  $views = $enabled + $disabled;
  $sorted = array_keys($enabled_sorted + $disabled_sorted);

  $rows = array();
  foreach ($sorted as $key) {
    $view = $views[$key];

    $row = array();
    $row[] = array(
      'data' => theme('label_machine_name__view', array(
        'label' => $view->get_human_name(),
        'machine_name' => $view->name,
      )),
      'class' => array('views-ui-name'),
      'data-label' => t('Name'),
    );
    $row[] = array(
      'data' => theme('views_ui_view_description', array('view' => $view)),
      'class' => array('views-ui-description'),
      'data-label' => t('Description'),
    );
    $row[] = array(
      'data' => theme('item_list', array('items' => _views_ui_get_displays($view))),
      'class' => array('views-ui-displays'),
      'data-label' => t('Displays'),
    );
    $row[] = array(
      'data' => theme('views_ui_view_storage', array('view' => $view)),
      'class' => array('views-ui-storage'),
      'data-label' => t('Storage state'),
    );
    $row[] = array(
      'data' => array(
        '#type' => 'operations',
        '#links' => _views_ui_get_operations($view),
      ),
      'class' => array('views-ui-operations'),
      'data-label' => t('Operations'),
    );

    $rows[] = array(
      'data' => $row,
      'class' => array(empty($view->disabled) ? 'enabled' : 'disabled'),
    );
  }

  $table = array(
    'header' => $header,
    'rows' => $rows,
    'empty' => t('No views match the search criteria.'),
    'attributes' => array(
      'id' => 'views-list',
      'class' => array('views-list'),
    ),
  );
  return theme('table', $table);
}

/**
 * Given a view, return a list of operations that can be performed on it.
 */
function _views_ui_get_operations(view $view) {
  $links = array();
  if ($view->disabled) {
    $links['enable'] = array(
      'title' => t('Enable'),
      'href' => 'admin/structure/views/view/' . $view->name . '/enable',
      'query' => array('token' => backdrop_get_token($view->name)),
    );
  }
  $links['configure'] = array(
    'title' => t('Configure'),
    'href' => 'admin/structure/views/view/' . $view->name,
  );
  $links['clone'] = array(
    'title' => t('Clone'),
    'href' => 'admin/structure/views/view/' . $view->name . '/clone',
  );
  if (!$view->disabled) {
    $links['disable'] = array(
      'title' => t('Disable'),
      'href' => 'admin/structure/views/view/' . $view->name . '/disable',
      'query' => array('token' => backdrop_get_token($view->name)),
    );
  }
  if ($view->storage == VIEWS_STORAGE_NORMAL) {
    $links['delete'] = array(
      'title' => t('Delete'),
      'href' => 'admin/structure/views/view/' . $view->name . '/delete',
    );
  }
  elseif ($view->storage == VIEWS_STORAGE_OVERRIDE) {
    $links['revert'] = array(
      'title' => t('Revert'),
      'href' => 'admin/structure/views/view/' . $view->name . '/revert',
    );
  }
  if (module_exists('config') && user_access('synchronize configuration')) {
    $links['export'] = array(
      'title' => t('Export'),
      'href' => 'admin/config/development/configuration/single/export',
      'query' => array(
        'group' => 'Views',
        'name' => 'views.view.' . $view->name,
      ),
    );
  }
  return $links;
}

/**
 * Page callback to add a new view.
 */
function views_ui_add_page() {
  views_ui_add_admin_css();
  backdrop_set_title(t('Add view'));
  return backdrop_get_form('views_ui_add_form');
}

/**
 * Form builder for the "Add view" page.
 */
function views_ui_add_form($form, &$form_state) {
  $form['#attached']['js'][] = backdrop_get_path('module', 'views_ui') . '/js/views-admin.js';
  $form['#attributes']['class'] = array('views-admin');

  $form['human_name'] = array(
    '#type' => 'textfield',
    '#title' => t('View name'),
    '#required' => TRUE,
    '#size' => 32,
    '#default_value' => !empty($form_state['view']) ? $form_state['view']->human_name : '',
    '#maxlength' => 255,
  );
  $form['name'] = array(
    '#type' => 'machine_name',
    '#maxlength' => 128,
    '#machine_name' => array(
      'exists' => 'views_get_view',
      'source' => array('human_name'),
    ),
    '#description' => t('A unique machine-readable name for this View. It must only contain lowercase letters, numbers, and underscores.'),
  );

  $form['description_enable'] = array(
    '#type' => 'checkbox',
    '#title' => t('Description'),
  );
  $form['description'] = array(
    '#type' => 'textfield',
    '#title' => t('Provide description'),
    '#title_display' => 'invisible',
    '#size' => 64,
    '#default_value' => !empty($form_state['view']) ? $form_state['view']->description : '',
    '#states' => array(
      'visible' => array(
        ':input[name="description_enable"]' => array('checked' => TRUE),
      ),
    ),
  );

  // Create a wrapper for the entire dynamic portion of the form. Everything
  // that can be updated by AJAX goes somewhere inside here. For example, this
  // is needed by "Show" dropdown (below); it changes the base table of the
  // view and therefore potentially requires all options on the form to be
  // dynamically updated.
  $form['displays'] = array();

  // Create the part of the form that allows the user to select the basic
  // properties of what the view will display.
  $form['displays']['show'] = array(
    '#type' => 'fieldset',
    '#tree' => TRUE,
    '#attributes' => array('class' => array('container-inline')),
  );

  // Create the "Show" dropdown, which allows the base table of the view to be
  // selected.
  $wizard_plugins = views_ui_get_wizards();
  $options = array();
  foreach ($wizard_plugins as $key => $wizard) {
    $options[$key] = $wizard['title'];
  }
  $form['displays']['show']['wizard_key'] = array(
    '#type' => 'select',
    '#title' => t('Show'),
    '#options' => $options,
  );
  $show_form = &$form['displays']['show'];
  $show_form['wizard_key']['#default_value'] = views_ui_get_selected($form_state, array('show', 'wizard_key'), 'node', $show_form['wizard_key']);
  // Changing this dropdown updates the entire content of $form['displays'] via
  // AJAX.
  views_ui_add_ajax_trigger($show_form, 'wizard_key', array('displays'));

  // Build the rest of the form based on the currently selected wizard plugin.
  $wizard_key = $show_form['wizard_key']['#default_value'];
  $get_instance = $wizard_plugins[$wizard_key]['get_instance'];
  $wizard_instance = $get_instance($wizard_plugins[$wizard_key]);
  $form = $wizard_instance->build_form($form, $form_state);

  $form['actions']['#type'] = 'actions';
  $form['actions']['continue'] = array(
    '#type' => 'submit',
    '#value' => t('Continue and configure'),
    '#validate' => array('views_ui_wizard_form_validate'),
    '#submit' => array('views_ui_add_form_store_edit_submit'),
    '#process' => array_merge(array('views_ui_default_button'), element_info_property('submit', '#process', array())),
    '#weight' => -1,
  );
  $form['actions']['save'] = array(
    '#type' => 'submit',
    '#value' => t('Save view'),
    '#validate' => array('views_ui_wizard_form_validate'),
    '#submit' => array('views_ui_add_form_save_submit'),
  );

  $path = 'admin/structure/views';
  $options = array();
  $options['attributes']['class'][] = 'form-cancel';

  $form['actions']['cancel'] = array(
    '#type' => 'link',
    '#title' => t('Cancel'),
    '#href' => $path,
    '#options' => $options,
    '#weight' => 1,
  );

  return $form;
}

/**
 * Gets the current value of a #select element, from within a form constructor function.
 *
 * This function is intended for use in highly dynamic forms (in particular the
 * add view wizard) which are rebuilt in different ways depending on which
 * triggering element (AJAX or otherwise) was most recently fired. For example,
 * sometimes it is necessary to decide how to build one dynamic form element
 * based on the value of a different dynamic form element that may not have
 * even been present on the form the last time it was submitted. This function
 * takes care of resolving those conflicts and gives you the proper current
 * value of the requested #select element.
 *
 * By necessity, this function sometimes uses non-validated user input from
 * $form_state['input'] in making its determination. Although it performs some
 * minor validation of its own, it is not complete. The intention is that the
 * return value of this function should only be used to help decide how to
 * build the current form the next time it is reloaded, not to be saved as if
 * it had gone through the normal, final form validation process. Do NOT use
 * the results of this function for any other purpose besides deciding how to
 * build the next version of the form.
 *
 * @param $form_state
 *   The  standard associative array containing the current state of the form.
 * @param $parents
 *   An array of parent keys that point to the part of the submitted form
 *   values that are expected to contain the element's value (in the case where
 *   this form element was actually submitted). In a simple case (assuming
 *   #tree is TRUE throughout the form), if the select element is located in
 *   $form['wrapper']['select'], so that the submitted form values would
 *   normally be found in $form_state['values']['wrapper']['select'], you would
 *   pass array('wrapper', 'select') for this parameter.
 * @param $default_value
 *   The default value to return if the #select element does not currently have
 *   a proper value set based on the submitted input.
 * @param $element
 *   An array representing the current version of the #select element within
 *   the form.
 *
 * @return
 *   The current value of the #select element. A common use for this is to feed
 *   it back into $element['#default_value'] so that the form will be rendered
 *   with the correct value selected.
 */
function views_ui_get_selected($form_state, $parents, $default_value, $element) {
  // For now, don't trust this to work on anything but a #select element.
  if (!isset($element['#type']) || $element['#type'] != 'select' || !isset($element['#options'])) {
    return $default_value;
  }

  // If there is a user-submitted value for this element that matches one of
  // the currently available options attached to it, use that. We need to check
  // $form_state['input'] rather than $form_state['values'] here because the
  // triggering element often has the #limit_validation_errors property set to
  // prevent unwanted errors elsewhere on the form. This means that the
  // $form_state['values'] array won't be complete. We could make it complete
  // by adding each required part of the form to the #limit_validation_errors
  // property individually as the form is being built, but this is difficult to
  // do for a highly dynamic and extensible form. This method is much simpler.
  if (!empty($form_state['input'])) {
    $key_exists = NULL;
    $submitted = backdrop_array_get_nested_value($form_state['input'], $parents, $key_exists);
    // Check that the user-submitted value is one of the allowed options before
    // returning it. This is not a substitute for actual form validation;
    // rather it is necessary because, for example, the same select element
    // might have #options A, B, and C under one set of conditions but #options
    // D, E, F under a different set of conditions. So the form submission
    // might have occurred with option A selected, but when the form is rebuilt
    // option A is no longer one of the choices. In that case, we don't want to
    // use the value that was submitted anymore but rather fall back to the
    // default value.
    if ($key_exists && in_array($submitted, array_keys($element['#options']))) {
      return $submitted;
    }
  }

  // Fall back on returning the default value if nothing was returned above.
  return $default_value;
}

/**
 * Converts a form element in the add view wizard to be AJAX-enabled.
 *
 * This function takes a form element and adds AJAX behaviors to it such that
 * changing it triggers another part of the form to update automatically. It
 * also adds a submit button to the form that appears next to the triggering
 * element and that duplicates its functionality for users who do not have
 * JavaScript enabled (the button is automatically hidden for users who do have
 * JavaScript).
 *
 * To use this function, call it directly from your form builder function
 * immediately after you have defined the form element that will serve as the
 * JavaScript trigger. Calling it elsewhere (such as in hook_form_alter()) may
 * mean that the non-JavaScript fallback button does not appear in the correct
 * place in the form.
 *
 * @param $wrapping_element
 *   The element whose child will server as the AJAX trigger. For example, if
 *   $form['some_wrapper']['triggering_element'] represents the element which
 *   will trigger the AJAX behavior, you would pass $form['some_wrapper'] for
 *   this parameter.
 * @param $trigger_key
 *   The key within the wrapping element that identifies which of its children
 *   serves as the AJAX trigger. In the above example, you would pass
 *   'triggering_element' for this parameter.
 * @param $refresh_parents
 *   An array of parent keys that point to the part of the form that will be
 *   refreshed by AJAX. For example, if triggering the AJAX behavior should
 *   cause $form['dynamic_content']['section'] to be refreshed, you would pass
 *   array('dynamic_content', 'section') for this parameter.
 */
function views_ui_add_ajax_trigger(&$wrapping_element, $trigger_key, $refresh_parents) {
  $seen_ids = &backdrop_static(__FUNCTION__ . ':seen_ids', array());
  $seen_buttons = &backdrop_static(__FUNCTION__ . ':seen_buttons', array());

  // Add the AJAX behavior to the triggering element.
  $triggering_element = &$wrapping_element[$trigger_key];
  $triggering_element['#ajax']['callback'] = 'views_ui_ajax_update_form';
  // We do not use backdrop_html_id() to get an ID for the AJAX wrapper, because
  // it remembers IDs across AJAX requests (and won't reuse them), but in our
  // case we need to use the same ID from request to request so that the
  // wrapper can be recognized by the AJAX system and its content can be
  // dynamically updated. So instead, we will keep track of duplicate IDs
  // (within a single request) on our own, later in this function.
  $triggering_element['#ajax']['wrapper'] = 'edit-view-' . implode('-', $refresh_parents) . '-wrapper';

  // Add a submit button for users who do not have JavaScript enabled. It
  // should be displayed next to the triggering element on the form.
  $button_key = $trigger_key . '_trigger_update';
  $wrapping_element[$button_key] = array(
    '#type' => 'submit',
    // Hide this button when JavaScript is enabled.
    '#attributes' => array('class' => array('js-hide')),
    '#submit' => array('views_ui_nojs_submit'),
    // Add a process function to limit this button's validation errors to the
    // triggering element only. We have to do this in #process since until the
    // form API has added the #parents property to the triggering element for
    // us, we don't have any (easy) way to find out where its submitted values
    // will eventually appear in $form_state['values'].
    '#process' => array_merge(array('views_ui_add_limited_validation'), element_info_property('submit', '#process', array())),
    // Add an after-build function that inserts a wrapper around the region of
    // the form that needs to be refreshed by AJAX (so that the AJAX system can
    // detect and dynamically update it). This is done in #after_build because
    // it's a convenient place where we have automatic access to the complete
    // form array, but also to minimize the chance that the HTML we add will
    // get clobbered by code that runs after we have added it.
    '#after_build' => array_merge(element_info_property('submit', '#after_build', array()), array('views_ui_add_ajax_wrapper')),
  );
  // Copy #weight and #access from the triggering element to the button, so
  // that the two elements will be displayed together.
  foreach (array('#weight', '#access') as $property) {
    if (isset($triggering_element[$property])) {
      $wrapping_element[$button_key][$property] = $triggering_element[$property];
    }
  }
  // For easiest integration with the form API and the testing framework, we
  // always give the button a unique #value, rather than playing around with
  // #name.
  $button_title = !empty($triggering_element['#title']) ? $triggering_element['#title'] : $trigger_key;
  if (empty($seen_buttons[$button_title])) {
    $wrapping_element[$button_key]['#value'] = t('Update "@title" choice', array(
      '@title' => $button_title,
    ));
    $seen_buttons[$button_title] = 1;
  }
  else {
    $wrapping_element[$button_key]['#value'] = t('Update "@title" choice (@number)', array(
      '@title' => $button_title,
      '@number' => ++$seen_buttons[$button_title],
   ));
  }

  // Attach custom data to the triggering element and submit button, so we can
  // use it in both the process function and AJAX callback.
  $ajax_data = array(
    'wrapper' => $triggering_element['#ajax']['wrapper'],
    'trigger_key' => $trigger_key,
    'refresh_parents' => $refresh_parents,
    // Keep track of duplicate wrappers so we don't add the same wrapper to the
    // page more than once.
    'duplicate_wrapper' => !empty($seen_ids[$triggering_element['#ajax']['wrapper']]),
  );
  $seen_ids[$triggering_element['#ajax']['wrapper']] = TRUE;
  $triggering_element['#views_ui_ajax_data'] = $ajax_data;
  $wrapping_element[$button_key]['#views_ui_ajax_data'] = $ajax_data;
}

/**
 * Processes a non-JavaScript fallback submit button to limit its validation errors.
 */
function views_ui_add_limited_validation($element, &$form_state) {
  // Retrieve the AJAX triggering element so we can determine its parents. (We
  // know it's at the same level of the complete form array as the submit
  // button, so all we have to do to find it is swap out the submit button's
  // last array parent.)
  $array_parents = $element['#array_parents'];
  array_pop($array_parents);
  $array_parents[] = $element['#views_ui_ajax_data']['trigger_key'];
  $ajax_triggering_element = backdrop_array_get_nested_value($form_state['complete_form'], $array_parents);

  // Limit this button's validation to the AJAX triggering element, so it can
  // update the form for that change without requiring that the rest of the
  // form be filled out properly yet.
  $element['#limit_validation_errors'] = array($ajax_triggering_element['#parents']);

  // If we are in the process of a form submission and this is the button that
  // was clicked, the form API workflow in form_builder() will have already
  // copied it to $form_state['triggering_element'] before our #process
  // function is run. So we need to make the same modifications in $form_state
  // as we did to the element itself, to ensure that #limit_validation_errors
  // will actually be set in the correct place.
  if (!empty($form_state['triggering_element'])) {
    $clicked_button = &$form_state['triggering_element'];
    if ($clicked_button['#name'] == $element['#name'] && $clicked_button['#value'] == $element['#value']) {
      $clicked_button['#limit_validation_errors'] = $element['#limit_validation_errors'];
    }
  }

  return $element;
}

/**
 * After-build function that adds a wrapper to a form region (for AJAX refreshes).
 *
 * This function inserts a wrapper around the region of the form that needs to
 * be refreshed by AJAX, based on information stored in the corresponding
 * submit button form element.
 */
function views_ui_add_ajax_wrapper($element, &$form_state) {
  // Don't add the wrapper <div> if the same one was already inserted on this
  // form.
  if (empty($element['#views_ui_ajax_data']['duplicate_wrapper'])) {
    // Find the region of the complete form that needs to be refreshed by AJAX.
    // This was earlier stored in a property on the element.
    $complete_form = &$form_state['complete_form'];
    $refresh_parents = $element['#views_ui_ajax_data']['refresh_parents'];
    $refresh_element = backdrop_array_get_nested_value($complete_form, $refresh_parents);

    // The HTML ID that AJAX expects was also stored in a property on the
    // element, so use that information to insert the wrapper <div> here.
    $id = $element['#views_ui_ajax_data']['wrapper'];
    $refresh_element += array(
      '#prefix' => '',
      '#suffix' => '',
    );
    $refresh_element['#prefix'] = '<div id="' . $id . '" class="views-ui-ajax-wrapper">' . $refresh_element['#prefix'];
    $refresh_element['#suffix'] .= '</div>';

    // Copy the element that needs to be refreshed back into the form, with our
    // modifications to it.
    backdrop_array_set_nested_value($complete_form, $refresh_parents, $refresh_element);
  }

  return $element;
}

/**
 * Updates a part of the add view form via AJAX.
 *
 * @return
 *   The part of the form that has changed.
 */
function views_ui_ajax_update_form($form, $form_state) {
  // The region that needs to be updated was stored in a property of the
  // triggering element by views_ui_add_ajax_trigger(), so all we have to do is
  // retrieve that here.
  return backdrop_array_get_nested_value($form, $form_state['triggering_element']['#views_ui_ajax_data']['refresh_parents']);
}

/**
 * Non-Javascript fallback for updating the add view form.
 */
function views_ui_nojs_submit($form, &$form_state) {
  $form_state['rebuild'] = TRUE;
}

/**
 * Validate the add view form.
 */
function views_ui_wizard_form_validate($form, &$form_state) {
  $wizard = views_ui_get_wizard($form_state['values']['show']['wizard_key']);
  $form_state['wizard'] = $wizard;
  $get_instance = $wizard['get_instance'];
  $form_state['wizard_instance'] = $get_instance($wizard);
  $errors = $form_state['wizard_instance']->validate($form, $form_state);
  foreach ($errors as $name => $message) {
    form_set_error($name, $message);
  }
}

/**
 * Process the add view form, 'save'.
 */
function views_ui_add_form_save_submit($form, &$form_state) {
  try {
    $view = $form_state['wizard_instance']->create_view($form, $form_state);
  }
  catch (ViewsWizardException $e) {
    backdrop_set_message($e->getMessage(), 'error');
    $form_state['redirect'] = 'admin/structure/views';
  }
  $view->save();

  $form_state['redirect'] = 'admin/structure/views';
  if (!empty($view->display['page'])) {
    $display = $view->display['page'];
    if ($display->handler->has_path()) {
      $one_path = $display->handler->get_option('path');
      if (strpos($one_path, '%') === FALSE) {
        backdrop_set_message(t('Your view was saved. You may <a href="@configure_view_link">configure it</a> or <a href="@views_listing_page_link">return to the views listing page.</a>', array(
          '@configure_view_link' => url('admin/structure/views/view/' . $view->name . '/configure'),
          '@views_listing_page_link' => url('admin/structure/views/list'),
        )));
        $form_state['redirect'] = $one_path;  // Path to the view if it has one.
        return;
      }
    }
  }
  backdrop_set_message(t('Your view was saved. You may configure it from the list below.'));
}

/**
 * Process the add view form, 'continue'.
 */
function views_ui_add_form_store_edit_submit($form, &$form_state) {
  try {
    $view = $form_state['wizard_instance']->create_view($form, $form_state);
  }
  catch (ViewsWizardException $e) {
    backdrop_set_message($e->getMessage(), 'error');
    $form_state['redirect'] = 'admin/structure/views';
  }
  // Just cache it temporarily to configure it.
  views_ui_cache_set($view);

  // If there is a destination query, ensure we still redirect the user to the
  // configure view page, and then redirect the user to the destination.
  $destination = array();
  if (isset($_GET['destination'])) {
    $destination = backdrop_get_destination();
    unset($_GET['destination']);
  }
  $form_state['redirect'] = array('admin/structure/views/view/' . $view->name, array('query' => $destination));
}

/**
 * Cancel the add view form.
 */
function views_ui_add_form_cancel_submit($form, &$form_state) {
  $form_state['redirect'] = 'admin/structure/views';
}

/**
 * Form element validation handler for a taxonomy autocomplete field.
 *
 * This allows a taxonomy autocomplete field to be validated outside the
 * standard Field API workflow, without passing in a complete field widget.
 * Instead, all that is required is that $element['#field_name'] contain the
 * name of the taxonomy autocomplete field that is being validated.
 *
 * This function is currently not used for validation directly, although it
 * could be. Instead, it is only used to store the term IDs and vocabulary name
 * in the element value, based on the tags that the user typed in.
 *
 * @see taxonomy_autocomplete_validate()
 */
function views_ui_taxonomy_autocomplete_validate($element, &$form_state) {
  $value = array();
  if ($tags = $element['#value']) {
    // Get the machine names of the vocabularies we will search, keyed by the
    // vocabulary IDs.
    $field = field_info_field($element['#field_name']);
    $vocabularies = array();
    if (!empty($field['settings']['allowed_values'])) {
      $vocabularies = $field['settings']['allowed_values'];
      foreach ($vocabularies as $index => $settings) {
        $vocabularies[$index] = $settings['vocabulary'];
      }
    }
    // Store the term ID of each (valid) tag that the user typed.
    $typed_terms = backdrop_explode_tags($tags);
    foreach ($typed_terms as $typed_term) {
      if ($terms = taxonomy_term_load_multiple(array(), array('name' => trim($typed_term), 'vocabulary' => $vocabularies))) {
        $term = array_pop($terms);
        $value['tids'][] = $term->tid;
      }
    }
    // Store the term IDs along with the name of the vocabulary. Currently
    // Views (as well as the Field UI) assumes that there will only be one
    // vocabulary, although technically the API allows there to be more than
    // one.
    if (!empty($value['tids'])) {
      $value['tids'] = array_unique($value['tids']);
      $value['vocabulary'] = array_pop($vocabularies);
    }
  }
  form_set_value($element, $value, $form_state);
}

/**
 * Page to delete a view.
 */
function views_ui_break_lock_confirm($form, &$form_state, $view) {
  $form_state['view'] = &$view;
  $form = array();

  if (empty($view->locked)) {
    $form['message']['#markup'] = t('There is no lock on view %name to break.', array('%name' => $view->name));
    return $form;
  }

  $cancel = 'admin/structure/views/view/' . $view->name . '/configure';
  $account = user_load($view->locked->uid);
  return confirm_form($form,
                  t('Are you sure you want to break the lock on view %name?',
                  array('%name' => $view->name)),
                  $cancel,
                  t('By breaking this lock, any unsaved changes made by !user will be lost!', array('!user' => theme('username', array('account' => $account)))),
                  t('Break lock'),
                  t('Cancel'));
}

/**
 * Submit handler to break_lock a view.
 */
function views_ui_break_lock_confirm_submit(&$form, &$form_state) {
  tempstore_clear('views.view', $form_state['view']->name);
  $form_state['redirect'] = 'admin/structure/views/view/' . $form_state['view']->name . '/configure';
  backdrop_set_message(t('The lock has been broken and you may now configure this view.'));
}

/**
 * Helper function to return the used display_id for the configure page.
 *
 * This function handles access to the display.
 */
function views_ui_edit_page_display($view, $display_id) {
  // Determine the displays available for configuring.
  if ($tabs = views_ui_edit_page_display_tabs($view, $display_id)) {
    // If a display isn't specified, use the first one.
    if (empty($display_id)) {
      foreach ($tabs as $id => $tab) {
        if (!isset($tab['#access']) || $tab['#access']) {
          $display_id = $id;
          break;
        }
      }
    }
    // If a display is specified, but we don't have access to it, return
    // an access denied page.
    if ($display_id && (!isset($tabs[$display_id]) || (isset($tabs[$display_id]['#access']) && !$tabs[$display_id]['#access']))) {
      return MENU_ACCESS_DENIED;
    }

    return $display_id;
  }
  elseif ($display_id) {
    return MENU_ACCESS_DENIED;
  }
  else {
    $display_id = NULL;
  }

  return $display_id;
}

/**
 * Page callback for the Configure View page.
 */
function views_ui_edit_page($view, $display_id = NULL) {
  $display_id = views_ui_edit_page_display($view, $display_id);
  if (!in_array($display_id, array(MENU_ACCESS_DENIED, MENU_NOT_FOUND))) {
    $build = array();
    $build['edit_form'] = backdrop_get_form('views_ui_edit_form', $view, $display_id);
    $build['preview'] = views_ui_build_preview($view, $display_id, FALSE);
  }
  else {
    $build = $display_id;
  }

  return $build;
}

function views_ui_build_preview($view, $display_id, $render = TRUE) {
  if (isset($_POST['ajax_html_ids'])) {
    unset($_POST['ajax_html_ids']);
  }

  $build = array(
    '#theme_wrappers' => array('container'),
    '#attributes' => array('id' => 'views-preview-wrapper', 'class' => 'views-admin clearfix'),
  );

  $form_state = array('build_info' => array('args' => array($view, $display_id)));
  $build['controls'] = backdrop_build_form('views_ui_preview_form', $form_state);

  $args = array();
  if (!empty($form_state['values']['view_args'])) {
    $args = explode('/', $form_state['values']['view_args']);
  }

  $build['preview'] = array(
    '#theme_wrappers' => array('container'),
    '#attributes' => array('id' => 'views-live-preview'),
    '#markup' => $render ? views_ui_preview($view->clone_view(), $display_id, $args) : '',
  );

  return $build;
}

/**
 * Form builder callback for configuring a View.
 *
 * @see views_ui_ajax_get_form()
 */
function views_ui_edit_form($form, &$form_state, $view, $display_id = NULL) {
  // Do not allow the form to be cached, because $form_state['view'] can become
  // stale between page requests.
  // See views_ui_ajax_get_form() for how this affects #ajax.
  // @todo To remove this and allow the form to be cacheable:
  //   - Change $form_state['view'] to $form_state['temporary']['view'].
  //   - Add a #process function to initialize $form_state['temporary']['view']
  //     on cached form submissions.
  $form_state['no_cache'] = TRUE;

  if ($display_id) {
    if (!$view->set_display($display_id)) {
      $form['#markup'] = t('Invalid display id @display', array('@display' => $display_id));
      return $form;
    }

    $view->fix_missing_relationships();
  }

  $form['#tree'] = TRUE;
  // @todo When more functionality is added to this form, cloning here may be
  //   too soon. But some of what we do with $view later in this function
  //   results in making it unserializable due to PDO limitations.
  $form_state['view'] = clone($view);

  $form['#attached']['library'][] = array('system', 'ui.tabs');
  $form['#attached']['library'][] = array('system', 'ui.dialog');
  $form['#attached']['library'][] = array('system', 'backdrop.ajax');
  $form['#attached']['library'][] = array('system', 'jquery.form');
  // TODO: This should be getting added to the page when an ajax popup calls
  // for it, instead of having to add it manually here.
  $form['#attached']['js'][] = 'core/misc/tabledrag.js';

  $form['#attached']['css'] = views_ui_get_admin_css();
  $module_path = backdrop_get_path('module', 'views_ui');

  $form['#attached']['js'][] = $module_path . '/js/views-admin.js';
  $form['#attached']['js'][] = array(
    'data' => array('views' => array('ajax' => array(
      'id' => '#views-ajax-body',
      'title' => '#views-ajax-title',
      'popup' => '#views-ajax-popup',
      'defaultForm' => views_ui_get_default_ajax_message(),
    ))),
    'type' => 'setting',
  );

  $form += array(
    '#prefix' => '',
    '#suffix' => '',
  );
  $form['#prefix'] = $form['#prefix'] . '<div class="views-edit-view views-admin clearfix">';
  $form['#suffix'] = '</div>' . $form['#suffix'];

  $form['#attributes']['class'] = array('form-edit');

  if (isset($view->locked) && is_object($view->locked)) {
    $form['locked'] = array(
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('view-locked', 'messages', 'warning')),
      '#markup' => t('This view is being configured by user !user, and is therefore locked from configuring by others. This lock is !age old. Click here to <a href="!break">break this lock</a>.', array('!user' => theme('username', array('account' => user_load($view->locked->uid))), '!age' => format_interval(REQUEST_TIME - $view->locked->updated), '!break' => url('admin/structure/views/view/' . $view->name . '/break-lock'))),
    );
  }
  if (isset($view->vid) && $view->vid == 'new') {
    $message = t('* All changes are stored temporarily. Click Save to make your changes permanent. Click Cancel to discard the view.');
  }
  else {
    $message = t('* All changes are stored temporarily. Click Save to make your changes permanent. Click Cancel to discard your changes.');
  }

  $form['changed'] = array(
    '#theme_wrappers' => array('container'),
    '#attributes' => array('class' => array('view-changed', 'messages', 'warning')),
    '#markup' => $message,
    '#access' => empty($view->locked),
  );
  if (empty($view->changed)) {
    $form['changed']['#attributes']['class'][] = 'js-hide';
  }

  $form['actions'] = array(
    '#type' => 'actions',
    '#weight' => 0,
    '#access' => empty($view->locked),
  );

  if (empty($view->changed)) {
    $form['actions']['#attributes'] = array(
      'class' => array(
        'js-hide',
      ),
    );
  }

  $form['actions']['save'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
    // Taken from the "old" UI. @TODO: Review and rename.
    '#validate' => array('views_ui_edit_view_form_validate'),
    '#submit' => array('views_ui_edit_view_form_submit'),
  );
  $form['actions']['cancel'] = array(
    '#type' => 'submit',
    '#value' => t('Cancel'),
    '#submit' => array('views_ui_edit_view_form_cancel'),
  );

  $form['displays'] = array(
    '#prefix' => '<h1 class="unit-title">' . t('Displays') . '</h1>' . "\n" . '<div class="views-displays">',
    '#suffix' => '</div>',
  );

  $form['displays']['top'] = views_ui_render_display_top($view, $display_id);

  // The rest requires a display to be selected.
  if ($display_id) {
    $form_state['display_id'] = $display_id;

    // The part of the page where configuring will take place.
    $form['displays']['settings'] = array(
      '#theme_wrappers' => array('container'),
      '#id' => 'edit-display-settings',
      '#attributes' => array(),
    );

    // Add a text that the display is disabled.
    if (!empty($view->display[$display_id]->handler)) {
      $enabled = $view->display[$display_id]->handler->get_option('enabled');
      if (empty($enabled)) {
        $form['displays']['settings']['disabled']['#markup'] = t('This display is disabled.');
      }
    }
    $form['displays']['settings']['settings_content']= array(
      '#theme_wrappers' => array('container'),
      '#id' => 'edit-display-settings-content',
      '#attributes' => array(),
    );
    // Add the configure display content
    $form['displays']['settings']['settings_content']['tab_content'] = views_ui_get_display_tab($view, $display_id);
    $form['displays']['settings']['settings_content']['tab_content']['#theme_wrappers'] = array('container');
    $form['displays']['settings']['settings_content']['tab_content']['#attributes'] = array('class' => array('views-display-tab'));
    $form['displays']['settings']['settings_content']['tab_content']['#id'] = 'views-tab-' . $display_id;
    // Mark deleted displays as such.
    if (!empty($view->display[$display_id]->deleted)) {
      $form['displays']['settings']['settings_content']['tab_content']['#attributes']['class'][] = 'views-display-deleted';
    }
    // Mark disabled displays as such.
    if (empty($enabled)) {
      $form['displays']['settings']['settings_content']['tab_content']['#attributes']['class'][] = 'views-display-disabled';
    }

    // The content of the popup dialog.
    $form['ajax-area'] = array(
      '#theme_wrappers' => array('container'),
      '#id' => 'views-ajax-popup',
      '#attributes' => array(),
    );
    $form['ajax-area']['ajax-title'] = array(
      '#markup' => '<h2 id="views-ajax-title"></h2>',
    );
    $form['ajax-area']['ajax-body'] = array(
      '#theme_wrappers' => array('container'),
      '#id' => 'views-ajax-body',
      '#attributes' => array(),
      '#markup' => views_ui_get_default_ajax_message(),
    );
  }

  // If relationships had to be fixed, we want to get that into the cache
  // so that configurations work properly, and to try to get the user to save it
  // so that it's not using weird fixed up relationships.
  if (!empty($view->relationships_changed) && empty($_POST)) {
    backdrop_set_message(t('Missing relationships have been fixed automatically. Please verify these changes before saving.'));
    views_ui_cache_set($view);
  }
  return $form;
}

/**
 * Provide the preview formulas and the preview output, too.
 */
function views_ui_preview_form($form, &$form_state, $view, $display_id = 'default') {
  $form_state['no_cache'] = TRUE;
  $form_state['view'] = $view;

  $form['#attributes'] = array('class' => array('clearfix',));

  // Add a checkbox controlling whether or not this display auto-previews.
  $form['live_preview'] = array(
    '#type' => 'checkbox',
    '#id' => 'edit-displays-live-preview',
    '#title' => t('Auto preview'),
    '#default_value' => config_get('views_ui.settings', 'always_live_preview'),
  );

  // Add the arguments textfield
  $form['view_args'] = array(
    '#type' => 'textfield',
    '#title' => t('Preview with contextual filters:'),
    '#description' => t('Separate contextual filter values with a "/". For example, %example.', array('%example' => '40/12/10')),
    '#id' => 'preview-args',
  );

  // Add the preview button
  $form['button'] = array(
    '#type' => 'submit',
    '#value' => t('Update preview'),
    '#attributes' => array('class' => array('arguments-preview')),
    '#prefix' => '<div id="preview-submit-wrapper">',
    '#suffix' => '</div>',
    '#id' => 'preview-submit',
    '#submit' => array('views_ui_edit_form_submit_preview'),
    '#ajax' => array(
      'path' => 'admin/structure/views/view/' . $view->name . '/preview/' . $display_id . '/ajax',
      'wrapper' => 'views-preview-wrapper',
      'event' => 'click',
      'progress' => array('type' => 'throbber'),
      'method' => 'replace',
    ),
    // Make ENTER in arguments textfield (and other controls) submit the form
    // as this button, not the Save button.
    // @todo This only works for JS users. To make this work for nojs users,
    //   we may need to split Preview into a separate form.
    '#process' => array_merge(array('views_ui_default_button'), element_info_property('submit', '#process', array())),
  );
  $form['#action'] = url('admin/structure/views/view/' . $view->name .'/preview/' . $display_id);

  return $form;
}

/**
 * Render the top of the display so it can be updated during ajax operations.
 */
function views_ui_render_display_top($view, $display_id) {
  $element['#theme_wrappers'] = array('views_container');
  $element['#attributes']['class'] = array('views-display-top', 'clearfix');
  $element['#attributes']['id'] = array('views-display-top');

  // Extra actions for the display
  $element['extra_actions'] = array(
    '#type' => 'dropbutton',
    '#links' => array(
      'edit-details' => array(
        'title' => t('Change view name/description'),
        'href' => "admin/structure/views/nojs/config-details/$view->name",
        'attributes' => array('class' => array('views-ajax-link')),
      ),
      'analyze' => array(
        'title' => t('analyze view'),
        'href' => "admin/structure/views/nojs/analyze/$view->name/$display_id",
        'attributes' => array('class' => array('views-ajax-link')),
      ),
      'clone' => array(
        'title' => t('clone view'),
        'href' => "admin/structure/views/view/$view->name/clone",
      ),
      'export' => array(),  // Placeholder for export
      'reorder' => array(
        'title' => t('reorder displays'),
        'href' => "admin/structure/views/nojs/reorder-displays/$view->name/$display_id",
        'attributes' => array('class' => array('views-ajax-link')),
      ),
    ),
  );

  if (module_exists('config') && user_access('synchronize configuration')) {
    $element['extra_actions']['#links']['export'] = array(
      'title' => t('export view'),
      'href' => 'admin/config/development/configuration/single/export',
      'query' => array(
        'group' => 'Views',
        'name' => 'views.view.' . $view->name,
      ),
    );
  }
  else {
    unset($element['extra_actions']['#links']['export']);
  }

  // Let other modules add additional links here.
  backdrop_alter('views_ui_display_top_links', $element['extra_actions']['#links'], $view, $display_id);

  if (isset($view->storage) && $view->storage != VIEWS_STORAGE_DEFAULT) {
    if ($view->type == t('Overridden')) {
      $element['extra_actions']['#links']['revert'] = array(
        'title' => t('revert view'),
        'href' => "admin/structure/views/view/$view->name/revert",
        'query' => array('destination' => "admin/structure/views/view/$view->name"),
      );
    }
    else {
      $element['extra_actions']['#links']['delete'] = array(
        'title' => t('delete view'),
        'href' => "admin/structure/views/view/$view->name/delete",
      );
    }
  }

  // Determine the displays available for configuring.
  if ($tabs = views_ui_edit_page_display_tabs($view, $display_id)) {
    if ($display_id) {
      $tabs[$display_id]['#active'] = TRUE;
    }
    $tabs['#prefix'] = '<h2 class="element-invisible">' . t('Secondary tabs') . '</h2><ul id = "views-display-menu-tabs" class="tabs secondary">';
    $tabs['#suffix'] = '</ul>';
    $element['tabs'] = $tabs;
  }

  // Buttons for adding a new display.
  foreach (views_fetch_plugin_names('display', NULL, array($view->base_table)) as $type => $label) {
    $element['add_display'][$type] = array(
      '#type' => 'submit',
      '#value' => t('Add !display', array('!display' => $label)),
      '#limit_validation_errors' => array(),
      '#submit' => array('views_ui_edit_form_submit_add_display', 'views_ui_edit_form_submit_delay_destination'),
      '#attributes' => array('class' => array('add-display')),
      // Allow JavaScript to remove the 'Add ' prefix from the button label when
      // placing the button in a "Add" dropdown menu.
      '#process' => array_merge(array('views_ui_form_button_was_clicked'), element_info_property('submit', '#process', array())),
      '#values' => array(t('Add !display', array('!display' => $label)), $label),
    );
  }

  return $element;
}

function views_ui_get_default_ajax_message() {
  return '<div class="message">' . t("Click on an item to configure that item's details.") . '</div>';
}

/**
 * Submit handler to add a display to a view.
 */
function views_ui_edit_form_submit_add_display($form, &$form_state) {
  $view = $form_state['view'];

  // Create the new display.
  $parents = $form_state['triggering_element']['#parents'];
  $display_type = array_pop($parents);
  $display_id = $view->add_display($display_type);
  views_ui_cache_set($view);

  // Redirect to the new display's configure page.
  $form_state['redirect'] = 'admin/structure/views/view/' . $view->name . '/configure/' . $display_id;
}

/**
 * Submit handler to duplicate a display for a view.
 */
function views_ui_edit_form_submit_duplicate_display($form, &$form_state) {
  $view = $form_state['view'];
  $display_id = $form_state['display_id'];

  // Create the new display.
  $display = $view->display[$display_id];
  $new_display_id = $view->add_display($display->display_plugin);
  $view->display[$new_display_id] = clone $display;
  $view->display[$new_display_id]->id = $new_display_id;

  // By setting the current display the changed marker will appear on the new
  // display.
  $view->current_display = $new_display_id;
  views_ui_cache_set($view);

  // Redirect to the new display's configure page.
  $form_state['redirect'] = 'admin/structure/views/view/' . $view->name . '/configure/' . $new_display_id;
}

/**
 * Submit handler to clone a display as another display type.
 */
function views_ui_edit_form_submit_clone_display_as_type($form, &$form_state) {
  $view = $form_state['view'];
  $display_id = $form_state['display_id'];

  // Create the new display.
  $parents = $form_state['triggering_element']['#parents'];
  $display_type = array_pop($parents);
  $new_display_id = $view->add_display($display_type);

  // Let the display title be generated by the add_display method and set the
  // right display plugin, but keep the rest of the from from the original
  // display.
  $display_clone = clone $view->display[$display_id];
  unset($display_clone->display_title);
  unset($display_clone->display_plugin);
  $new_display_array = backdrop_array_merge_deep((array) $view->display[$new_display_id], (array) $display_clone);
  foreach ($new_display_array as $key => $value) {
    $view->display[$new_display_id]->{$key} = $value;
  }
  $view->display[$new_display_id]->id = $new_display_id;

  // By setting the current display, the "changed" marker will appear on the new
  // display.
  $view->current_display = $new_display_id;
  views_ui_cache_set($view);

  // Redirect to the new display's edit page.
  $form_state['redirect'] = 'admin/structure/views/view/' . $view->name . '/configure/' . $new_display_id;
}

/**
 * Submit handler to delete a display from a view.
 */
function views_ui_edit_form_submit_delete_display($form, &$form_state) {
  $view = $form_state['view'];
  $display_id = $form_state['display_id'];

  // Mark the display for deletion.
  $view->display[$display_id]->deleted = TRUE;
  views_ui_cache_set($view);

  // Redirect to the top-level configure page. The first remaining display will
  // become the active display.
  $form_state['redirect'] = 'admin/structure/views/view/' . $view->name;
}

/**
 * Submit handler to add a restore a removed display to a view.
 */
function views_ui_edit_form_submit_undo_delete_display($form, &$form_state) {
  // Create the new display
  $id = $form_state['display_id'];
  $form_state['view']->display[$id]->deleted = FALSE;

  // Store in cache
  views_ui_cache_set($form_state['view']);

  // Redirect to the top-level configure page.
  $form_state['redirect'] = 'admin/structure/views/view/' . $form_state['view']->name . '/configure/' . $id;
}

/**
 * Submit handler to enable a disabled display.
 */
function views_ui_edit_form_submit_enable_display($form, &$form_state) {
  $id = $form_state['display_id'];
  // set_option doesn't work because this would might affect upper displays
  $form_state['view']->display[$id]->handler->set_option('enabled', TRUE);

  // Store in cache
  views_ui_cache_set($form_state['view']);

  // Redirect to the top-level configure page.
  $form_state['redirect'] = 'admin/structure/views/view/' . $form_state['view']->name . '/configure/' . $id;
}

/**
 * Submit handler to disable display.
 */
function views_ui_edit_form_submit_disable_display($form, &$form_state) {
  $id = $form_state['display_id'];
  $form_state['view']->display[$id]->handler->set_option('enabled', FALSE);

  // Store in cache
  views_ui_cache_set($form_state['view']);

  // Redirect to the top-level configure page.
  $form_state['redirect'] = 'admin/structure/views/view/' . $form_state['view']->name . '/configure/' . $id;
}

/**
 * Submit handler when Preview button is clicked.
 */
function views_ui_edit_form_submit_preview($form, &$form_state) {
  // Rebuild the form with a pristine $view object.
  $form_state['build_info']['args'][0] = views_ui_cache_load($form_state['view']->name);
  $form_state['show_preview'] = TRUE;
  $form_state['rebuild'] = TRUE;
}

/**
 * Submit handler for form buttons that do not complete a form workflow.
 *
 * The Configure View form is a multistep form workflow, but with state managed
 * by the Views object cache rather than $form_state['rebuild']. Without this
 * submit handler, buttons that add or remove displays would redirect to the
 * destination parameter (e.g., when the Configure View form is linked to from a
 * contextual link). This handler can be added to buttons whose form submission
 * should not yet redirect to the destination.
 */
function views_ui_edit_form_submit_delay_destination($form, &$form_state) {
  if (isset($_GET['destination']) && $form_state['redirect'] !== FALSE) {
    if (!isset($form_state['redirect'])) {
      $form_state['redirect'] = $_GET['q'];
    }
    if (is_string($form_state['redirect'])) {
      $form_state['redirect'] = array($form_state['redirect']);
    }
    $options = isset($form_state['redirect'][1]) ? $form_state['redirect'][1] : array();
    if (!isset($options['query']['destination'])) {
      $options['query']['destination'] = $_GET['destination'];
    }
    $form_state['redirect'][1] = $options;
    unset($_GET['destination']);
  }
}

/**
 * Adds tabs for navigating across Displays when configuring a View.
 *
 * This function can be called from hook_menu_local_tasks_alter() to implement
 * these tabs as secondary local tasks, or it can be called from elsewhere if
 * having them as secondary local tasks isn't desired. The caller is responsible
 * for setting the active tab's #active property to TRUE.
 *
 * @param view $view
 *    The view which will be configured.
 * @param $display_id
 *    The display_id which is configured on the current request.
 */
function views_ui_edit_page_display_tabs($view, $display_id = NULL) {
  $tabs = array();

  // Create a tab for each display.
  foreach ($view->display as $id => $display) {
    $tabs[$id] = array(
      '#theme' => 'menu_local_task',
      '#link' => array(
        'title' => views_ui_get_display_label($view, $id),
        'href' => 'admin/structure/views/view/' . $view->name . '/configure/' . $id,
        'localized_options' => array(),
      ),
    );
    if (!empty($display->deleted)) {
      $tabs[$id]['#link']['localized_options']['attributes']['class'][] = 'views-display-deleted-link';
    }
    if (isset($display->display_options['enabled']) && !$display->display_options['enabled']) {
      $tabs[$id]['#link']['localized_options']['attributes']['class'][] = 'views-display-disabled-link';
    }
  }

  // If the default display isn't supposed to be shown, don't display its tab, unless it's the only display.
  if ((!views_ui_show_default_display($view) && $display_id != 'default') && count($tabs) > 1) {
    $tabs['default']['#access'] = FALSE;
  }

  // Mark the display tab as red to show validation errors.
  $view->validate();
  foreach ($view->display as $id => $display) {
    if (!empty($view->display_errors[$id])) {
      // Always show the tab.
      $tabs[$id]['#access'] = TRUE;
      // Add a class to mark the error and a title to make a hover tip.
      $tabs[$id]['#link']['localized_options']['attributes']['class'][] = 'error';
      $tabs[$id]['#link']['localized_options']['attributes']['title'] = t('This display has one or more validation errors; please review it.');
    }
  }

  return $tabs;
}

/**
 * Controls whether the default display should have its own tab on configure.
 */
function views_ui_show_default_display($view) {
  // Always show the default display for advanced users who prefer that mode.
  $advanced_mode = config_get('views_ui.settings', 'show_default_display');
  // For other users, show the default display only if there are no others, and
  // hide it if there's at least one "real" display.
  $additional_displays = (count($view->display) == 1);

  return $advanced_mode || $additional_displays;
}

/**
 * Returns a renderable array representing the configure page for one display.
 */
function views_ui_get_display_tab($view, $display_id) {
  $build = array();
  $display = $view->display[$display_id];
  // If the plugin doesn't exist, display an error message instead of a
  // configure page.
  if (empty($display->handler)) {
    $title = isset($display->display_title) ? $display->display_title : t('Invalid');
    // @TODO: Improved UX for the case where a plugin is missing.
    $build['#markup'] = t("Error: Display @display refers to a plugin named '@plugin', but that plugin is not available.", array('@display' => $display->id, '@plugin' => $display->display_plugin));
  }
  // Build the content of the configure page.
  else {
    $build['details'] = views_ui_get_display_tab_details($view, $display);
  }
  // In AJAX context, views_ui_regenerate_tab() returns this outside of form
  // context, so hook_form_views_ui_edit_form_alter() is insufficient.
  backdrop_alter('views_ui_display_tab', $build, $view, $display_id);
  return $build;
}

/**
 * Helper function to get the display details section of the configure UI.
 *
 * @param $view
 * @param $display
 *
 * @return array
 *   A renderable page build array.
 */
function views_ui_get_display_tab_details($view, $display) {
  $display_title = views_ui_get_display_label($view, $display->id, FALSE);
  $build = array(
    '#theme_wrappers' => array('container'),
    '#attributes' => array('id' => 'edit-display-settings-details'),
  );

  $plugin = views_fetch_plugin_data('display', $view->display[$display->id]->display_plugin);
  $is_display_deleted = !empty($display->deleted);
  $is_deletable = empty($plugin['no remove']);
  // The default display cannot be cloned.
  $is_default = $display->id == 'default';
  // @todo: Figure out why get_option doesn't work here.
  $is_enabled = $display->handler->get_option('enabled');

  if ($display->id != 'default') {
    $build['top']['#theme_wrappers'] = array('container');
    $build['top']['#attributes']['id'] = 'edit-display-settings-top';
    $build['top']['#attributes']['class'] = array('views-ui-display-tab-actions', 'views-ui-display-tab-bucket', 'clearfix');

    // The Delete, Duplicate and Undo Delete buttons.
    $build['top']['actions'] = array(
      '#theme_wrappers' => array('dropbutton_wrapper'),
    );

    // Because some of the 'links' are actually submit buttons, we have to
    // manually wrap each item in <li> and the whole list in <ul>.
    $build['top']['actions']['prefix']['#markup'] = '<ul class="dropbutton">';

    if (!$is_display_deleted) {
      if (!$is_enabled) {
        $build['top']['actions']['enable'] = array(
          '#type' => 'submit',
          '#value' => t('enable @display_title', array('@display_title' => $display_title)),
          '#limit_validation_errors' => array(),
          '#submit' => array('views_ui_edit_form_submit_enable_display', 'views_ui_edit_form_submit_delay_destination'),
          '#prefix' => '<li class="enable">',
          '#suffix' => '</li>',
        );
      }
      // Add a link to view the page.
      elseif ($display->handler->has_path()) {
        $path = $display->handler->get_path();
        if (strpos($path, '%') === FALSE) {
          $build['top']['actions']['path'] = array(
            '#type' => 'link',
            '#title' => t('view @display', array('@display' => $display->display_title)),
            '#options' => array('alt' => array(t("Go to the real page for this display"))),
            '#href' => $path,
            '#prefix' => '<li class="view">',
            '#suffix' => '</li>',
          );
        }
      }
      if (!$is_default) {
        // Add "Clone" operation for the current plugin type.
        $build['top']['actions']['duplicate'] = array(
          '#type' => 'submit',
          '#value' => t('clone @display_title', array('@display_title' => $display_title)),
          '#limit_validation_errors' => array(),
          '#submit' => array('views_ui_edit_form_submit_duplicate_display', 'views_ui_edit_form_submit_delay_destination'),
          '#prefix' => '<li class="duplicate">',
          '#suffix' => '</li>',
        );

        $plugin_names = views_fetch_plugin_names('display', NULL, array($view->base_table));
        // Remove the plugin type of the current display from the list of
        // plugins.
        unset($plugin_names[$display->display_plugin]);
        // Add "Clone as" operations for the remaining plugin types.
        foreach ($plugin_names as $type => $label) {
          $build['top']['actions']['clone_as'][$type] = array(
            '#type' => 'submit',
            '#value' => t('clone as @type', array('@type' => $label)),
            '#limit_validation_errors' => array(),
            '#submit' => array('views_ui_edit_form_submit_clone_display_as_type', 'views_ui_edit_form_submit_delay_destination'),
            '#prefix' => '<li class="duplicate duplicate-as-"' . $type . '>',
            "#suffix" => '</li>',
          );
        }

      }
      if ($is_deletable) {
        $build['top']['actions']['delete'] = array(
          '#type' => 'submit',
          '#value' => t('delete @display_title', array('@display_title' => $display_title)),
          '#limit_validation_errors' => array(),
          '#submit' => array('views_ui_edit_form_submit_delete_display', 'views_ui_edit_form_submit_delay_destination'),
          '#prefix' => '<li class="delete">',
          '#suffix' => '</li>',
        );
      }
      if ($is_enabled) {
        $build['top']['actions']['disable'] = array(
          '#type' => 'submit',
          '#value' => t('disable @display_title', array('@display_title' => $display_title)),
          '#limit_validation_errors' => array(),
          '#submit' => array('views_ui_edit_form_submit_disable_display', 'views_ui_edit_form_submit_delay_destination'),
          '#prefix' => '<li class="disable">',
          '#suffix' => '</li>',
        );
      }
    }
    else {
      $build['top']['actions']['undo_delete'] = array(
        '#type' => 'submit',
        '#value' => t('undo delete of @display_title', array('@display_title' => $display_title)),
        '#limit_validation_errors' => array(),
        '#submit' => array('views_ui_edit_form_submit_undo_delete_display', 'views_ui_edit_form_submit_delay_destination'),
        '#prefix' => '<li class="undo-delete">',
        '#suffix' => '</li>',
      );
    }
    $build['top']['actions']['suffix']['#markup'] = '</ul>';

    // The area above the three columns.
    $build['top']['display_title'] = array(
      '#theme' => 'views_ui_display_tab_setting',
      '#description' => t('Display name'),
      '#link' => $display->handler->option_link(check_plain($display_title), 'display_title'),
    );
  }

  $build['columns'] = array();
  $build['columns']['#theme_wrappers'] = array('container');
  $build['columns']['#attributes'] = array('id' => 'edit-display-settings-main', 'class' => array('clearfix', 'views-display-columns'));

  $build['columns']['first']['#theme_wrappers'] = array('container');
  $build['columns']['first']['#attributes'] = array('class' => array('views-display-column', 'first'));

  $build['columns']['second']['#theme_wrappers'] = array('container');
  $build['columns']['second']['#attributes'] = array('class' => array('views-display-column', 'second'));

  $build['columns']['second']['settings'] = array();
  $build['columns']['second']['header'] = array();
  $build['columns']['second']['footer'] = array();
  $build['columns']['second']['pager'] = array();

  // The third column buckets are wrapped in a container.
  // @todo: Convert this to #type = details when available.
  $build['columns']['third']['#theme_wrappers'] = array('container');
  $build['columns']['third']['#attributes'] = array('class' => array('views-display-column', 'third'));
  // Specify an id that won't change after AJAX requests. Use the same ID across
  // different displays of the same view, so changing displays doesn't
  // affect the column display.
  $build['columns']['third']['#attributes']['id'] = 'views-ui-advanced-column-' . $view->name;
  $build['columns']['third']['collapse']['#theme_wrappers'] = array('container');
  $build['columns']['third']['collapse']['#attributes'] = array();

  // Each option (e.g. title, access, display as grid/table/list) fits into one
  // of several "buckets," or boxes (Format, Fields, Sort, and so on).
  $buckets = array();

  // Fetch options from the display plugin, with a list of buckets they go into.
  $options = array();
  $display->handler->options_summary($buckets, $options);

  // Place each option into its bucket.
  foreach ($options as $id => $option) {
    // Each option self-identifies as belonging in a particular bucket.
    $buckets[$option['category']]['build'][$id] = views_ui_edit_form_get_build_from_option($id, $option, $view, $display);
  }

  // Place each bucket into the proper column.
  foreach ($buckets as $id => $bucket) {
    // Let buckets identify themselves as belonging in a column.
    if (isset($bucket['column']) && isset($build['columns'][$bucket['column']])) {
      $column = $bucket['column'];
    }
    // If a bucket doesn't pick one of our predefined columns to belong to, put
    // it in the last one.
    else {
      $column = 'third';
    }
    if (isset($bucket['build']) && is_array($bucket['build'])) {
      // The third column is a collapsible div, so
      // the structure of the form is a little different for this column
      if ($column === 'third') {
        $build['columns'][$column]['collapse'][$id] = $bucket['build'];
        $build['columns'][$column]['collapse'][$id]['#theme_wrappers'][] = 'views_ui_display_tab_bucket';
        $build['columns'][$column]['collapse'][$id]['#title'] = !empty($bucket['title']) ? $bucket['title'] : '';
        $build['columns'][$column]['collapse'][$id]['#name'] = !empty($bucket['title']) ? $bucket['title'] : $id;
      }
      else {
        $build['columns'][$column][$id] = $bucket['build'];
        $build['columns'][$column][$id]['#theme_wrappers'][] = 'views_ui_display_tab_bucket';
        $build['columns'][$column][$id]['#title'] = !empty($bucket['title']) ? $bucket['title'] : '';
        $build['columns'][$column][$id]['#name'] = !empty($bucket['title']) ? $bucket['title'] : $id;
      }
    }
  }

  $build['columns']['first']['fields'] = views_ui_edit_form_get_bucket('field', $view, $display);
  $build['columns']['first']['filters'] = views_ui_edit_form_get_bucket('filter', $view, $display);
  $build['columns']['first']['sorts'] = views_ui_edit_form_get_bucket('sort', $view, $display);
  $build['columns']['second']['header'] = views_ui_edit_form_get_bucket('header', $view, $display);
  $build['columns']['second']['footer'] = views_ui_edit_form_get_bucket('footer', $view, $display);
  $build['columns']['third']['collapse']['arguments'] = views_ui_edit_form_get_bucket('argument', $view, $display);
  $build['columns']['third']['collapse']['relationships'] = views_ui_edit_form_get_bucket('relationship', $view, $display);
  $build['columns']['third']['collapse']['empty'] = views_ui_edit_form_get_bucket('empty', $view, $display);

  return $build;
}

/**
 * Build a renderable array representing one option on the configure form.
 *
 * This function might be more logical as a method on an object, if a suitable
 * object emerges out of refactoring.
 */
function views_ui_edit_form_get_build_from_option($id, $option, $view, $display) {
  $option_build = array();
  $option_build['#theme'] = 'views_ui_display_tab_setting';

  $option_build['#description'] = $option['title'];

  $option_build['#link'] = $display->handler->option_link($option['value'], $id, '', empty($option['desc']) ? '' : $option['desc']);

  $option_build['#links'] = array();
  if (!empty($option['links']) && is_array($option['links'])) {
    foreach ($option['links'] as $link_id => $link_value) {
      $option_build['#settings_links'][] = $display->handler->option_link($option['setting'], $link_id, 'views-button-configure', $link_value);
    }
  }

  if (!empty($display->handler->options['defaults'][$id])) {
    $display_id = 'default';
    $option_build['#defaulted'] = TRUE;
  }
  else {
    $display_id = $display->id;
    if (!$display->handler->is_default_display()) {
      if ($display->handler->defaultable_sections($id)) {
        $option_build['#overridden'] = TRUE;
      }
    }
  }
  $option_build['#attributes']['class'][] = backdrop_clean_css_identifier($display_id . '-' . $id);
  if (!empty($view->changed_sections[$display_id . '-' . $id])) {
    $option_build['#changed'] = TRUE;
  }
  return $option_build;
}

/**
 * Move form elements into fieldsets for presentation purposes.
 *
 * Many views forms use #tree = TRUE to keep their values in a hierarchy for
 * easier storage. Moving the form elements into fieldsets during form building
 * would break up that hierarchy. Therefore, we wait until the pre_render stage,
 * where any changes we make affect presentation only and aren't reflected in
 * $form_state['values'].
 */
function views_ui_pre_render_add_fieldset_markup($form) {
  foreach (element_children($form) as $key) {
    $element = $form[$key];
    // In our form builder functions, we added an arbitrary #fieldset property
    // to any element that belongs in a fieldset. If this form element has that
    // property, move it into its fieldset.
    if (isset($element['#fieldset']) && isset($form[$element['#fieldset']])) {
      $form[$element['#fieldset']][$key] = $element;
      // Remove the original element this duplicates.
      unset($form[$key]);
    }
  }

  return $form;
}

/**
 * Flattens the structure of an element containing the #flatten property.
 *
 * If a form element has #flatten = TRUE, then all of it's children
 * get moved to the same level as the element itself.
 * So $form['to_be_flattened'][$key] becomes $form[$key], and
 * $form['to_be_flattened'] gets unset.
 */
function views_ui_pre_render_flatten_data($form) {
  foreach (element_children($form) as $key) {
    $element = $form[$key];
    if (!empty($element['#flatten'])) {
      foreach (element_children($element) as $child_key) {
        $form[$child_key] = $form[$key][$child_key];
      }
      // All done, remove the now-empty parent.
      unset($form[$key]);
    }
  }

  return $form;
}

/**
 * Moves argument options into their place.
 *
 * When configuring the default argument behavior, almost each of the radio
 * buttons has its own fieldset shown bellow it when the radio button is
 * clicked. That fieldset is created through a custom form process callback.
 * Each element that has #argument_option defined and pointing to a default
 * behavior gets moved to the appropriate fieldset.
 * So if #argument_option is specified as 'default', the element is moved
 * to the 'default_options' fieldset.
 */
function views_ui_pre_render_move_argument_options($form) {
  foreach (element_children($form) as $key) {
    $element = $form[$key];
    if (!empty($element['#argument_option'])) {
      $container_name = $element['#argument_option'] . '_options';
      if (isset($form['no_argument']['default_action'][$container_name])) {
        $form['no_argument']['default_action'][$container_name][$key] = $element;
      }
      // Remove the original element this duplicates.
      unset($form[$key]);
    }
  }
  return $form;
}

/**
 * Custom form radios process function.
 *
 * Roll out a single radios element to a list of radios,
 * using the options array as index.
 * While doing that, create a container element underneath each option, which
 * contains the settings related to that option.
 *
 * @see form_process_radios()
 */
function views_ui_process_container_radios($element) {
  if (count($element['#options']) > 0) {
    foreach ($element['#options'] as $key => $choice) {
      $element += array($key => array());
      // Generate the parents as the autogenerator does, so we will have a
      // unique id for each radio button.
      $parents_for_id = array_merge($element['#parents'], array($key));

      $element[$key] += array(
        '#type' => 'radio',
        '#title' => $choice,
        // The key is sanitized in backdrop_attributes() during output from the
        // theme function.
        '#return_value' => $key,
        '#default_value' => isset($element['#default_value']) ? $element['#default_value'] : NULL,
        '#attributes' => $element['#attributes'],
        '#parents' => $element['#parents'],
        '#id' => backdrop_html_id('edit-' . implode('-', $parents_for_id)),
        '#ajax' => isset($element['#ajax']) ? $element['#ajax'] : NULL,
      );
      $element[$key . '_options'] = array(
        '#type' => 'container',
        '#attributes' => array('class' => array('views-admin-dependent')),
      );
    }
  }
  return $element;
}

/**
 * Form callback; Clone a view.
 */
function views_ui_clone_form($form, &$form_state, view $view) {
  backdrop_set_title(t('Clone the view @name?', array('@name' => $view->get_human_name())));
  $form_state['view'] = $view;

  $form['label'] = array(
    '#type' => 'textfield',
    '#title' => t('View name'),
    '#required' => TRUE,
    '#size' => 32,
    '#maxlength' => 255,
    '#default_value' => t('Clone of @label', array('@label' => $view->get_human_name())),
  );
  $form['name'] = array(
    '#type' => 'machine_name',
    '#maxlength' => 128,
    '#machine_name' => array(
      'exists' => 'views_get_view',
      'source' => array('label'),
    ),
    '#default_value' => '',
    '#description' => t('A unique machine-readable name for this View. It must only contain lowercase letters, numbers, and underscores.'),
  );

  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Clone'),
  );

  return $form;
}

/**
 * Submit handler for views_ui_clone_form().
 */
function views_ui_clone_form_submit($form, &$form_state) {
  // Get a safe clone of the source view.
  $new_view = $form_state['view']->clone_view();
  // Reset some values to allow deletion of cloned views.
  $new_view->module = '';
  $new_view->storage = VIEWS_STORAGE_NORMAL;
  // Set new machine name and label.
  $new_view->name = $form_state['values']['name'];
  $new_view->human_name = $form_state['values']['label'];
  $new_view->save();
  backdrop_set_message(t('The view %old_name as been cloned into %new_name.', array('%old_name' => $form_state['view']->get_human_name(), '%new_name' => $new_view->get_human_name())));
  $form_state['redirect'] = 'admin/structure/views/view/' . $new_view->name;
}

/**
 * Form callback; Delete a view.
 */
function views_ui_delete_form($form, &$form_state, view $view) {
  $form_state['view'] = $view;
  $question = t('Delete the view @name?', array('@name' => $view->get_human_name()));
  $path = 'admin/structure/views';
  $description = t('Deleting the view %name will remove all pages, blocks, and other displays provided by this view.', array('%name' => $view->get_human_name()));
  return confirm_form($form, $question, $path, $description, t('Delete'));
}

/**
 * Submit handler for views_ui_delete_form().
 */
function views_ui_delete_form_submit($form, &$form_state) {
  $name = $form_state['view']->get_human_name();
  $form_state['view']->delete();
  $form_state['redirect'] = 'admin/structure/views';
  backdrop_set_message(t('The view %name has been deleted.', array('%name' => $name)));
}

/**
 * Form callback; Delete a view.
 */
function views_ui_revert_form($form, &$form_state, view $view) {
  $form_state['view'] = $view;
  $question = t('Revert the view @name?', array('@name' => $view->get_human_name()));
  $path = 'admin/structure/views';
  $description = t('Reverting the view %name will restore it to the original settings provided by the "@module" module.', array('%name' => $view->get_human_name(), '@module' => $view->module));
  return confirm_form($form, $question, $path, $description, t('Revert'));
}

/**
 * Submit handler for views_ui_delete_form().
 */
function views_ui_revert_form_submit($form, &$form_state) {
  $name = $form_state['view']->get_human_name();
  $form_state['view']->revert();
  $form_state['redirect'] = 'admin/structure/views';
  backdrop_set_message(t('The view %name has been reverted to its defaults.', array('%name' => $name)));
}

/**
 * Menu callback; Enable a view and return to the view listing page.
 */
function views_ui_toggle_enable_page(view $view, $status) {
  // Validate the token for this page.
  if (empty($_GET['token']) || $_GET['token'] !== backdrop_get_token($view->name)) {
    return MENU_ACCESS_DENIED;
  }
  $view->disabled = !$status;
  $view->save();
  if ($status) {
    $message = t('The view %name has been enabled.', array('%name' => $view->get_human_name()));
  }
  else {
    $message = t('The view %name has been disabled.', array('%name' => $view->get_human_name()));
  }
  backdrop_set_message($message);
  backdrop_goto('admin/structure/views');
}

/**
 * Validate that a view is complete and whole.
 */
function views_ui_edit_view_form_validate($form, &$form_state) {
  // Do not validate cancel or delete or revert.
  if (empty($form_state['clicked_button']['#value']) || $form_state['clicked_button']['#value'] != t('Save')) {
    return;
  }

  $errors = $form_state['view']->validate();
  if ($errors !== TRUE) {
    foreach ($errors as $error) {
      form_set_error('', $error);
    }
  }
}

/**
 * Submit handler for the configure view form.
 */
function views_ui_edit_view_form_submit($form, &$form_state) {
  // Go through and remove displayed scheduled for removal.
  foreach ($form_state['view']->display as $id => $display) {
    if (!empty($display->deleted)) {
      unset($form_state['view']->display[$id]);
    }
  }
  // Rename display ids if needed.
  foreach ($form_state['view']->display as $id => $display) {
    if (!empty($display->new_id)) {
      $form_state['view']->display[$id]->id = $display->new_id;
      // Redirect the user to the renamed display to be sure that the page itself exists and doesn't throw errors.
      $form_state['redirect'] = 'admin/structure/views/view/' . $form_state['view']->name . '/configure/' . $display->new_id;
    }
  }

  // Direct the user to the right url, if the path of the display has changed.
  if (!empty($_GET['destination'])) {
    $destination = $_GET['destination'];
    // Find out the first display which has a changed path and redirect to this url.
    $old_view = views_get_view($form_state['view']->name);
    foreach ($old_view->display as $id => $display) {
      // Only check for displays with a path.
      if (!isset($display->display_options['path'])) {
        continue;
      }
      $old_path = $display->display_options['path'];
      if (($display->display_plugin == 'page') && ($old_path == $destination) && ($old_path != $form_state['view']->display[$id]->display_options['path'])) {
        $destination = $form_state['view']->display[$id]->display_options['path'];
        unset($_GET['destination']);
      }
    }
    $form_state['redirect'] = $destination;
  }

  $form_state['view']->save();
  backdrop_set_message(t('The view %name has been saved.', array('%name' => $form_state['view']->get_human_name())));

  // Remove this view from cache so we can configure it properly.
  tempstore_clear('views.view', $form_state['view']->name);
}

/**
 * Submit handler for the configure view form.
 */
function views_ui_edit_view_form_cancel($form, &$form_state) {
  // Remove this view from cache so configurations will be lost.
  tempstore_clear('views.view', $form_state['view']->name);
  if (empty($form['view']->vid)) {
    // I seem to have to backdrop_goto here because I can't get fapi to
    // honor the redirect target. Not sure what I screwed up here.
    backdrop_goto('admin/structure/views');
  }
}

function views_ui_edit_view_form_delete($form, &$form_state) {
  unset($_REQUEST['destination']);
  // Redirect to the delete confirm page
  $form_state['redirect'] = array('admin/structure/views/view/' . $form_state['view']->name . '/delete', array('query' => backdrop_get_destination() + array('cancel' => 'admin/structure/views/view/' . $form_state['view']->name . '/configure')));
}

/**
 * Add information about a section to a display.
 */
function views_ui_edit_form_get_bucket($type, $view, $display) {
  $build = array(
    '#theme_wrappers' => array('views_ui_display_tab_bucket'),
  );
  $types = views_object_types();

  $build['#overridden'] = FALSE;
  $build['#defaulted'] = FALSE;
  if (module_exists('advanced_help')) {
    $build['#item_help_icon'] = array(
      '#theme' => 'advanced_help_topic',
      '#module' => 'views',
      '#topic' => $type,
    );
  }

  $build['#name'] = $build['#title'] = $types[$type]['title'];

  // Different types now have different rearrange forms, so we use this switch
  // to get the right one.
  switch ($type) {
    case 'filter':
      $rearrange_url = "admin/structure/views/nojs/rearrange-$type/$view->name/$display->id/$type";
      $rearrange_text = t('And/Or, Rearrange');
      // TODO: Add another class to have another symbol for filter rearrange.
      $class = 'icon compact rearrange';
      break;
    case 'field':
      // Fetch the style plugin info so we know whether to list fields or not.
      $style_plugin = $display->handler->get_plugin();
      $uses_fields = $style_plugin && $style_plugin->uses_fields();
      if (!$uses_fields) {
        $build['fields'][] = array(
          '#markup' => t('The selected style or row format does not utilize fields.'),
          '#theme_wrappers' => array('views_container'),
          '#attributes' => array('class' => array('views-display-setting')),
        );
        return $build;
      }

    default:
      $rearrange_url = "admin/structure/views/nojs/rearrange/$view->name/$display->id/$type";
      $rearrange_text = t('Rearrange');
      $class = 'icon compact rearrange';
  }

  // Create an array of actions to pass to theme_links
  $actions = array();
  $count_handlers = count($display->handler->get_handlers($type));
  $actions['add'] = array(
    'title' => t('Add'),
    'href' => "admin/structure/views/nojs/add-item/$view->name/$display->id/$type",
    'attributes'=> array('class' => array('icon compact add', 'views-ajax-link'), 'title' => t('Add'), 'id' => 'views-add-' . $type),
    'html' => TRUE,
  );
  if ($count_handlers > 0) {
    $actions['rearrange'] = array(
      'title' => $rearrange_text,
      'href' => $rearrange_url,
      'attributes' => array('class' => array($class, 'views-ajax-link'), 'title' => t('Rearrange'), 'id' => 'views-rearrange-' . $type),
      'html' => TRUE,
    );
  }

  // Render the array of links
  $build['actions'] = array(
    '#type' => 'operations',
    '#links' => $actions,
  );

  if (!$display->handler->is_default_display()) {
    if (!$display->handler->is_defaulted($types[$type]['plural'])) {
      $build['#overridden'] = TRUE;
    }
    else {
      $build['#defaulted'] = TRUE;
    }
  }

  // If there's an options form for the bucket, link to it.
  if (!empty($types[$type]['options'])) {
    $build['#title'] = l($build['#title'], "admin/structure/views/nojs/config-type/$view->name/$display->id/$type", array('attributes' => array('class' => array('views-ajax-link'), 'id' => 'views-title-' . $type)));
  }

  static $relationships = NULL;
  if (!isset($relationships)) {
    // Get relationship labels
    $relationships = array();
    // @todo: get_handlers()
    $handlers = $display->handler->get_option('relationships');
    if ($handlers) {
      foreach ($handlers as $id => $info) {
        $handler = $display->handler->get_handler('relationship', $id);
        $relationships[$id] = $handler->label();
      }
    }
  }

  // Filters can now be grouped so we do a little bit extra:
  $groups = array();
  $grouping = FALSE;
  if ($type == 'filter') {
    $group_info = $view->display_handler->get_option('filter_groups');
    // If there is only one group but it is using the "OR" filter, we still
    // treat it as a group for display purposes, since we want to display the
    // "OR" label next to items within the group.
    if (!empty($group_info['groups']) && (count($group_info['groups']) > 1 || current($group_info['groups']) == 'OR')) {
      $grouping = TRUE;
      $groups = array(0 => array());
    }
  }

  $build['fields'] = array();

  foreach ($display->handler->get_option($types[$type]['plural']) as $id => $field) {
    // Build the option link for this handler ("Node: ID = post").
    $build['fields'][$id] = array();
    $build['fields'][$id]['#theme'] = 'views_ui_display_tab_setting';

    $handler = $display->handler->get_handler($type, $id);
    if (empty($handler)) {
      $build['fields'][$id]['#class'][] = 'broken';
      $field_name = t('Broken/missing handler: @table > @field', array('@table' => $field['table'], '@field' => $field['field']));
      $build['fields'][$id]['#link'] = l($field_name, "admin/structure/views/nojs/config-item/$view->name/$display->id/$type/$id", array('attributes' => array('class' => array('views-ajax-link')), 'html' => TRUE));
      continue;
    }

    $field_name = check_plain($handler->ui_name(TRUE));
    if (!empty($field['relationship']) && !empty($relationships[$field['relationship']])) {
      $field_name = '(' . $relationships[$field['relationship']] . ') ' . $field_name;
    }

    $description = filter_xss_admin($handler->admin_summary());
    $link_text = $field_name . (empty($description) ? '' : " ($description)");
    $link_attributes = array('class' => array('views-ajax-link'));
    if (!empty($field['exclude'])) {
      $link_attributes['class'][] = 'views-field-excluded';
      $link_text .= ' ['. t("hidden") .']';
    }
    $build['fields'][$id]['#link'] = l($link_text, "admin/structure/views/nojs/config-item/$view->name/$display->id/$type/$id", array('attributes' => $link_attributes, 'html' => TRUE));
    $build['fields'][$id]['#class'][] = backdrop_clean_css_identifier($display->id . '-' . $type . '-' . $id);
    if (!empty($view->changed_sections[$display->id . '-' . $type . '-' . $id])) {
      // @TODO: #changed is no longer being used?
      $build['fields'][$id]['#changed'] = TRUE;
    }

    if ($display->handler->use_group_by() && $handler->use_group_by()) {
      $build['fields'][$id]['#settings_links'][] = l('<span class="label">' . t('Aggregation settings') . '</span>', "admin/structure/views/nojs/config-item-group/$view->name/$display->id/$type/$id", array('attributes' => array('class' => 'views-button-configure views-ajax-link', 'title' => t('Aggregation settings')), 'html' => true));
    }

    if ($handler->has_extra_options()) {
      $build['fields'][$id]['#settings_links'][] = l('<span class="label">' . t('Settings') . '</span>', "admin/structure/views/nojs/config-item-extra/$view->name/$display->id/$type/$id", array('attributes' => array('class' => array('views-button-configure', 'views-ajax-link'), 'title' => t('Settings')), 'html' => true));
    }

    if ($grouping) {
      $gid = $handler->options['group'];

      // Show in default group if the group does not exist.
      if (empty($group_info['groups'][$gid])) {
        $gid = 0;
      }
      $groups[$gid][] = $id;
    }
  }

  // If using grouping, re-order fields so that they show up properly in the list.
  if ($type == 'filter' && $grouping) {
    $store = $build['fields'];
    $build['fields'] = array();
    foreach ($groups as $gid => $contents) {
      // Display an operator between each group.
      if (!empty($build['fields'])) {
        $build['fields'][] = array(
          '#theme' => 'views_ui_display_tab_setting',
          '#class' => array('views-group-text'),
          '#link' => ($group_info['operator'] == 'OR' ? t('OR') : t('AND')),
        );
      }
      // Display an operator between each pair of filters within the group.
      $keys = array_keys($contents);
      $last = end($keys);
      foreach ($contents as $key => $pid) {
        if ($key != $last) {
          $store[$pid]['#link'] .= '&nbsp;&nbsp;' . ($group_info['groups'][$gid] == 'OR' ? t('OR') : t('AND'));
        }
        $build['fields'][$pid] = $store[$pid];
      }
    }
  }

  return $build;
}

/**
 * Regenerate the current tab for AJAX updates.
 */
function views_ui_regenerate_tab(&$view, &$output, $display_id) {
  if (!$view->set_display('default')) {
    return;
  }

  // Regenerate the main display area.
  $build = views_ui_get_display_tab($view, $display_id);
  views_ui_add_microweights($build);
  $output[] = ajax_command_html('#views-tab-' . $display_id, backdrop_render($build));

  // Regenerate the top area so changes to display names and order will appear.
  $build = views_ui_render_display_top($view, $display_id);
  views_ui_add_microweights($build);
  $output[] = ajax_command_replace('#views-display-top', backdrop_render($build));
}

/**
 * Recursively adds microweights to a render array, similar to what form_builder() does for forms.
 *
 * @todo Submit a core patch to fix backdrop_render() to do this, so that all
 *   render arrays automatically preserve array insertion order, as forms do.
 */
function views_ui_add_microweights(&$build) {
  $count = 0;
  foreach (element_children($build) as $key) {
    if (!isset($build[$key]['#weight'])) {
      $build[$key]['#weight'] = $count/1000;
    }
    views_ui_add_microweights($build[$key]);
    $count++;
  }
}

/**
 * Provide a standard set of Apply/Cancel/OK buttons for the forms. Also provide
 * a hidden op operator because the forms plugin doesn't seem to properly
 * provide which button was clicked.
 *
 * TODO: Is the hidden op operator still here somewhere, or is that part of the
 * docblock outdated?
 */
function views_ui_standard_form_buttons(&$form, &$form_state, $form_id, $name = NULL, $third = NULL, $submit = NULL) {
  $form['actions'] = array(
    '#type' => 'actions',
  );

  if (empty($name)) {
    $name = t('Apply');
    $view = $form_state['view'];
    if (!empty($view->stack) && count($view->stack) > 1) {
      $name = t('Apply and continue');
    }
    $names = array(t('Apply'), t('Apply and continue'));
  }

  // Views provides its own custom handling of AJAX form submissions. Usually
  // this happens at the same path, but custom paths may be specified in
  // $form_state.
  $form_path = empty($form_state['path']) ? current_path() : $form_state['path'];

  // Forms that are purely informational set an ok_button flag, so we know not
  // to create an "Apply" button for them.
  if (empty($form_state['ok_button'])) {
    $form['actions']['submit'] = array(
      '#type' => 'submit',
      '#value' => $name,
      '#id' => 'edit-submit-' . backdrop_html_id($form_id),
      // The regular submit handler ($form_id . '_submit') does not apply if
      // we're updating the default display. It does apply if we're updating
      // the current display. Since we have no way of knowing at this point
      // which display the user wants to update, views_ui_standard_submit will
      // take care of running the regular submit handler as appropriate.
      '#submit' => array('views_ui_standard_submit'),
      '#ajax' => array(
        'path' => $form_path,
      ),
    );
    // Form API button click detection requires the button's #value to be the
    // same between the form build of the initial page request, and the initial
    // form build of the request processing the form submission. Ideally, the
    // button's #value shouldn't change until the form rebuild step. However,
    // views_ui_ajax_form() implements a different multistep form workflow than
    // the Form API does, and adjusts $view->stack prior to form processing, so
    // we compensate by extending button click detection code to support any of
    // the possible button labels.
    if (isset($names)) {
      $form['actions']['submit']['#values'] = $names;
      $form['actions']['submit']['#process'] = array_merge(array('views_ui_form_button_was_clicked'), element_info_property($form['actions']['submit']['#type'], '#process', array()));
    }
    // If a validation handler exists for the form, assign it to this button.
    if (function_exists($form_id . '_validate')) {
      $form['actions']['submit']['#validate'][] = $form_id . '_validate';
    }
  }

  // Create a "Cancel" button. For purely informational forms, label it "OK".
  $cancel_submit = function_exists($form_id . '_cancel') ? $form_id . '_cancel' : 'views_ui_standard_cancel';
  $form['actions']['cancel'] = array(
    '#type' => 'submit',
    '#value' => empty($form_state['ok_button']) ? t('Cancel') : t('Ok'),
    '#submit' => array($cancel_submit),
    '#validate' => array(),
    '#ajax' => array(
      'path' => $form_path,
    ),
  );

  // Some forms specify a third button, with a name and submit handler.
  if ($third) {
    if (empty($submit)) {
      $submit = 'third';
    }
    $third_submit = function_exists($form_id . '_' . $submit) ? $form_id . '_' . $submit : 'views_ui_standard_cancel';

    $form['actions'][$submit] = array(
      '#type' => 'submit',
      '#value' => $third,
      '#validate' => array(),
      '#submit' => array($third_submit),
      '#ajax' => array(
        'path' => $form_path,
      ),
    );
  }

  // Compatibility, to be removed later: // TODO: When is "later"?
  // We used to set these items on the form, but now we want them on the $form_state:
  if (isset($form['#title'])) {
    $form_state['title'] = $form['#title'];
  }
  if (isset($form['#help_topic'])) {
    $form_state['help_topic'] = $form['#help_topic'];
  }
  if (isset($form['#help_module'])) {
    $form_state['help_module'] = $form['#help_module'];
  }
  if (isset($form['#section'])) {
    $form_state['#section'] = $form['#section'];
  }
  // Finally, we never want these cached -- our object cache does that for us.
  $form['#no_cache'] = TRUE;

  // If this isn't an AJAX form, then we want to set the title.
  if (!empty($form['#title'])) {
    backdrop_set_title($form['#title']);
  }
}

/**
 * Basic submit handler applicable to all 'standard' forms.
 *
 * This submit handler determines whether the user wants the submitted changes
 * to apply to the default display or to the current display, and dispatches
 * control appropriately.
 */
function views_ui_standard_submit($form, &$form_state) {
  // Determine whether the values the user entered are intended to apply to
  // the current display or the default display.

  list($was_defaulted, $is_defaulted, $revert) = views_ui_standard_override_values($form, $form_state);

  // Mark the changed section of the view as changed.
  // TODO: Document why we are doing this, and see if we still need it.
  if (!empty($form['#section'])) {
    $form_state['view']->changed_sections[$form['#section']] = TRUE;
  }

  // Based on the user's choice in the display dropdown, determine which display
  // these changes apply to.
  if ($revert) {
    // If it's revert just change the override and return.
    $display = &$form_state['view']->display[$form_state['display_id']];
    $display->handler->options_override($form, $form_state);

    // Don't execute the normal submit handling but still store the changed view into cache.
    views_ui_cache_set($form_state['view']);
    return;
  }
  elseif ($was_defaulted === $is_defaulted) {
    // We're not changing which display these form values apply to.
    // Run the regular submit handler for this form.
  }
  elseif ($was_defaulted && !$is_defaulted) {
    // We were using the default display's values, but we're now overriding
    // the default display and saving values specific to this display.
    $display = &$form_state['view']->display[$form_state['display_id']];
    // options_override toggles the override of this section.
    $display->handler->options_override($form, $form_state);
    $display->handler->options_submit($form, $form_state);
  }
  elseif (!$was_defaulted && $is_defaulted) {
    // We used to have an override for this display, but the user now wants
    // to go back to the default display.
    // Overwrite the default display with the current form values, and make
    // the current display use the new default values.
    $display = &$form_state['view']->display[$form_state['display_id']];
    // options_override toggles the override of this section.
    $display->handler->options_override($form, $form_state);
    $display->handler->options_submit($form, $form_state);
  }

  $submit_handler = $form['#form_id'] . '_submit';
  if (function_exists($submit_handler)) {
    $submit_handler($form, $form_state);
  }
}

/**
 * Return the was_defaulted, is_defaulted and revert state of a form.
 */
function views_ui_standard_override_values($form, $form_state) {
  // Make sure the dropdown exists in the first place.
  if (isset($form_state['values']['override']['dropdown'])) {
    // #default_value is used to determine whether it was the default value or not.
    // So the available options are: $display, 'default' and 'default_revert', not 'defaults'.
    $was_defaulted = ($form['override']['dropdown']['#default_value'] === 'defaults');
    $is_defaulted = ($form_state['values']['override']['dropdown'] === 'default');
    $revert = ($form_state['values']['override']['dropdown'] === 'default_revert');

    if ($was_defaulted !== $is_defaulted && isset($form['#section'])) {
      // We're changing which display these values apply to.
      // Update the #section so it knows what to mark changed.
      $form['#section'] = str_replace('default-', $form_state['display_id'] . '-', $form['#section']);
    }
  }
  else {
    // The user didn't get the dropdown for overriding the default display.
    $was_defaulted = FALSE;
    $is_defaulted = FALSE;
    $revert = FALSE;
  }

  return array($was_defaulted, $is_defaulted, $revert);
}

/**
 * Submit handler for cancel button
 */
function views_ui_standard_cancel($form, &$form_state) {
  if (!empty($form_state['view']->changed) && isset($form_state['view']->form_cache)) {
    unset($form_state['view']->form_cache);
    views_ui_cache_set($form_state['view']);
  }

  $form_state['redirect'] = 'admin/structure/views/view/' . $form_state['view']->name . '/configure';
}

/**
 * Add a <select> dropdown for a given section, allowing the user to
 * change whether this info is stored on the default display or on
 * the current display.
 */
function views_ui_standard_display_dropdown(&$form, &$form_state, $section) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $displays = $view->display;
  $current_display = $view->display[$display_id];

  // Add the "2 of 3" progress indicator.
  // @TODO: Move this to a separate function if it's needed on any forms that
  // don't have the display dropdown.
  if ($form_progress = views_ui_get_form_progress($view)) {
    $form['progress']['#markup'] = '<div id="views-progress-indicator">' . t('@current of @total', array('@current' => $form_progress['current'], '@total' => $form_progress['total'])) . '</div>';
    $form['progress']['#weight'] = -1001;
  }

  if ($current_display->handler->is_default_display()) {
    return;
  }

  // Determine whether any other displays have overrides for this section.
  $section_overrides = FALSE;
  $section_defaulted = $current_display->handler->is_defaulted($section);
  foreach ($displays as $id => $display) {
    if ($id === 'default' || $id === $display_id) {
      continue;
    }
    if ($display->handler && !$display->handler->is_defaulted($section)) {
      $section_overrides = TRUE;
    }
  }

  $display_dropdown['default'] = ($section_overrides ? t('All displays (except overridden)') : t('All displays'));
  $display_dropdown[$display_id] = t('This @display_type (override)', array('@display_type' => $current_display->display_plugin));
  // Only display the revert option if we are in a overridden section.
  if (!$section_defaulted) {
    $display_dropdown['default_revert'] = t('Revert to default');
  }

  $form['override'] = array(
    '#prefix' => '<div class="views-override clearfix container-inline">',
    '#suffix' => '</div>',
    '#weight' => -1000,
    '#tree' => TRUE,
  );
  $form['override']['dropdown'] = array(
    '#type' => 'select',
    '#title' => t('For'), // @TODO: Translators may need more context than this.
    '#options' => $display_dropdown,
  );
  if ($current_display->handler->is_defaulted($section)) {
    $form['override']['dropdown']['#default_value'] = 'defaults';
  }
  else {
    $form['override']['dropdown']['#default_value'] = $display_id;
  }

}

/**
 * Get the user's current progress through the form stack.
 *
 * @param $view
 *   The current view.
 *
 * @return
 *   FALSE if the user is not currently in a multiple-form stack. Otherwise,
 *   an associative array with the following keys:
 *   - current: The number of the current form on the stack.
 *   - total: The total number of forms originally on the stack.
 */
function views_ui_get_form_progress($view) {
  $progress = FALSE;
  if (!empty($view->stack)) {
    $stack = $view->stack;
    // The forms on the stack have integer keys that don't change as the forms
    // are completed, so we can see which ones are still left.
    $keys = array_keys($view->stack);
    // Add 1 to the array keys for the benefit of humans, who start counting
    // from 1 and not 0.
    $current = reset($keys) + 1;
    $total = end($keys) + 1;
    if ($total > 1) {
      $progress = array();
      $progress['current'] = $current;
      $progress['total'] = $total;
    }
  }
  return $progress;
}


// --------------------------------------------------------------------------
// Various subforms for configuring the pieces of a view.

function views_ui_ajax_forms($key = NULL) {
  $forms = array(
    'display' => array(
      'form_id' => 'views_ui_edit_display_form',
      'args' => array('section'),
    ),
    'remove-display' => array(
      'form_id' => 'views_ui_remove_display_form',
      'args' => array(),
    ),
    'config-type' => array(
      'form_id' => 'views_ui_config_type_form',
      'args' => array('type'),
    ),
    'rearrange' => array(
      'form_id' => 'views_ui_rearrange_form',
      'args' => array('type'),
    ),
    'rearrange-filter' => array(
      'form_id' => 'views_ui_rearrange_filter_form',
      'args' => array('type'),
    ),
    'reorder-displays' => array(
      'form_id' => 'views_ui_reorder_displays_form',
      'args' => array(),
    ),
    'add-item' => array(
      'form_id' => 'views_ui_add_item_form',
      'args' => array('type'),
    ),
    'config-item' => array(
      'form_id' => 'views_ui_config_item_form',
      'args' => array('type', 'id'),
    ),
    'config-item-extra' => array(
      'form_id' => 'views_ui_config_item_extra_form',
      'args' => array('type', 'id'),
    ),
    'config-item-group' => array(
      'form_id' => 'views_ui_config_item_group_form',
      'args' => array('type', 'id'),
    ),
    'config-style' => array(
      'form_id' => 'views_ui_config_style_form',
      'args' => array('type', 'id'),
    ),
    'config-details' => array(
      'form_id' => 'views_ui_edit_details_form',
      'args' => array(),
    ),
    'analyze' => array(
      'form_id' => 'views_ui_analyze_view_form',
      'args' => array(),
    ),
  );

  if ($key) {
    return !empty($forms[$key]) ? $forms[$key] : NULL;
  }

  return $forms;
}

/**
 * Build a form identifier that we can use to see if one form
 * is the same as another. Since the arguments differ slightly
 * we do a lot of spiffy concatenation here.
 */
function views_ui_build_identifier($key, $view, $display_id, $args) {
  $form = views_ui_ajax_forms($key);
  // Automatically remove the single-form cache if it exists and
  // does not match the key.
  $identifier = implode('-', array($key, $view->name, $display_id));

  foreach ($form['args'] as $id) {
    $arg = (!empty($args)) ? array_shift($args) : NULL;
    $identifier .= '-' . $arg;
  }
  return $identifier;
}

/**
 * Build up a $form_state object suitable for use with backdrop_build_form
 * based on known information about a form.
 */
function views_ui_build_form_state($js, $key, &$view, $display_id, $args) {
  $form = views_ui_ajax_forms($key);
  // Build up form state
  $form_state = array(
    'form_key' => $key,
    'form_id' => $form['form_id'],
    'view' => &$view,
    'ajax' => $js,
    'display_id' => $display_id,
    'no_redirect' => TRUE,
  );

  foreach ($form['args'] as $id) {
    $form_state[$id] = (!empty($args)) ? array_shift($args) : NULL;
  }

  return $form_state;
}

/**
 * Create the menu path for one of our standard AJAX forms based upon known
 * information about the form.
 */
function views_ui_build_form_path($form_state) {
  $form = views_ui_ajax_forms($form_state['form_key']);
  $ajax = empty($form_state['ajax']) ? 'nojs' : 'ajax';
  $name = $form_state['view']->name;
  $path = "admin/structure/views/$ajax/$form_state[form_key]/$name/$form_state[display_id]";
  foreach ($form['args'] as $arg) {
    $path .= '/' . $form_state[$arg];
  }
  return $path;
}

/**
 * Backwards compatible wrapper function for views_ui_build_form_path().
 *
 * @deprecated since 1.0.0.
 */
function views_ui_build_form_url($form_state) {
  watchdog_deprecated_function('views_ui', __FUNCTION__);
  return views_ui_build_form_path($form_state);
}

/**
 * Add another form to the stack; clicking 'apply' will go to this form
 * rather than closing the ajax popup.
 */
function views_ui_add_form_to_stack($key, &$view, $display_id, $args, $top = FALSE, $rebuild_keys = FALSE) {
  if (empty($view->stack)) {
    $view->stack = array();
  }

  $stack = array(views_ui_build_identifier($key, $view, $display_id, $args), $key, &$view, $display_id, $args);
  // If we're being asked to add this form to the bottom of the stack, no
  // special logic is required. Our work is equally easy if we were asked to add
  // to the top of the stack, but there's nothing in it yet.
  if (!$top || empty($view->stack)) {
    $view->stack[] = $stack;
  }
  // If we're adding to the top of an existing stack, we have to maintain the
  // existing integer keys, so they can be used for the "2 of 3" progress
  // indicator (which will now read "2 of 4").
  else {
    $keys = array_keys($view->stack);
    $first = current($keys);
    $last = end($keys);
    for ($i = $last; $i >= $first; $i--) {
      if (!isset($view->stack[$i])) {
        continue;
      }
      // Move form number $i to the next position in the stack.
      $view->stack[$i + 1] = $view->stack[$i];
      unset($view->stack[$i]);
    }
    // Now that the previously $first slot is free, move the new form into it.
    $view->stack[$first] = $stack;
    ksort($view->stack);

    // Start the keys from 0 again, if requested.
    if ($rebuild_keys) {
      $view->stack = array_values($view->stack);
    }
  }
}

/**
 * Generic entry point to handle forms.
 *
 * We do this for consistency and to make it easy to chain forms
 * together.
 */
function views_ui_ajax_form($js, $key, $view, $display_id = '') {
  // Reset the cache of IDs. Backdrop rather aggressively prevents ID
  // duplication but this causes it to remember IDs that are no longer even
  // being used.
  if (isset($_POST['ajax_html_ids'])) {
    unset($_POST['ajax_html_ids']);
  }

  // AJAX requests may not have the triggering element set in POST, but ajax.js
  // adds a triggering element. Add to POST to ensure the correct button submit
  // handlers fire.
  if (isset($_POST['_triggering_element_name']) && isset($_POST['_triggering_element_value'])) {
    $_POST[$_POST['_triggering_element_name']] = $_POST['_triggering_element_value'];
  }

  $form = views_ui_ajax_forms($key);
  if (empty($form)) {
    return MENU_NOT_FOUND;
  }

  views_include('ajax');
  $args = func_get_args();
  // Remove the known args
  array_splice($args, 0, 4);

  $form_state = views_ui_build_form_state($js, $key, $view, $display_id, $args);
  // check to see if this is the top form of the stack. If it is, pop
  // it off; if it isn't, the user clicked somewhere else and the stack is
  // now irrelevant.
  if (!empty($view->stack)) {
    $identifier = views_ui_build_identifier($key, $view, $display_id, $args);
    // Retrieve the first form from the stack without changing the integer keys,
    // as they're being used for the "2 of 3" progress indicator.
    reset($view->stack);
    $key = key($view->stack);
    $top = current($view->stack);
    unset($view->stack[$key]);

    if (array_shift($top) != $identifier) {
      $view->stack = array();
    }
  }

  // Automatically remove the form cache if it is set and the key does
  // not match. This way navigating away from the form without hitting
  // update will work.
  if (isset($view->form_cache) && $key !== 0 && $view->form_cache['key'] != $key) {
    unset($view->form_cache);
  }

  // With the below logic, we may end up rendering a form twice (or two forms
  // each sharing the same element ids), potentially resulting in
  // backdrop_add_js() being called twice to add the same setting. backdrop_get_js()
  // is ok with that, but until ajax_render() is (http://drupal.org/node/208611),
  // reset the backdrop_add_js() static before rendering the second time.
  $backdrop_add_js_original = backdrop_add_js();
  $backdrop_add_js = &backdrop_static('backdrop_add_js');
  $output = views_ajax_form_wrapper($form_state['form_id'], $form_state);
  if ($form_state['submitted'] && empty($form_state['rerender'])) {
    // Sometimes we need to re-generate the form for multi-step type operations.
    $object = NULL;
    if (!empty($view->stack)) {
      $backdrop_add_js = $backdrop_add_js_original;
      $stack = $view->stack;
      $top = array_shift($stack);
      $top[0] = $js;

      // Change view into a reference.
      $stepview = $top[2];
      $top[2] = &$stepview;

      $form_state = call_user_func_array('views_ui_build_form_state', $top);
      $form_state['input'] = array();
      $form_state['path'] = views_ui_build_form_path($form_state);
      if (!$js) {
        return backdrop_goto(views_ui_build_form_path($form_state));
      }
      $output = views_ajax_form_wrapper($form_state['form_id'], $form_state);
    }
    elseif (!$js) {
      // if nothing on the stack, non-js forms just go back to the main view editor.
      return backdrop_goto("admin/structure/views/view/$view->name/configure");
    }
    else {
      $output = array();
      $output[] = ajax_command_close_modal_dialog();
      $output[] = views_ajax_command_show_buttons();
      $output[] = views_ajax_command_trigger_preview();
      if (!empty($form_state['#page_title'])) {
        $output[] = views_ajax_command_replace_title($form_state['#page_title']);
      }
    }
    // If this form was for view-wide changes, there's no need to regenerate
    // the display section of the form.
    if ($display_id !== '') {
      views_ui_regenerate_tab($view, $output, $display_id);
    }
  }

  return $js ? array('#type' => 'ajax', '#commands' => $output) : $output;
}

/**
 * Submit handler to add a restore a removed display to a view.
 */
function views_ui_remove_display_form_restore($form, &$form_state) {
  // Create the new display
  $id = $form_state['display_id'];
  $form_state['view']->display[$id]->deleted = FALSE;

  // Store in cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Form constructor callback to display analysis information on a view
 */
function views_ui_analyze_view_form($form, &$form_state) {
  $view = &$form_state['view'];

  $form['#title'] = t('View analysis');
  $form['#section'] = 'analyze';

  module_load_include('inc', 'views_ui', 'views_ui.analyze');
  $messages = views_ui_analyze_view($view);

  $form['analysis'] = array(
    '#prefix' => '<div class="form-item">',
    '#suffix' => '</div>',
    '#markup' => views_ui_analyze_format_result($view, $messages),
  );

  // Inform the standard button function that we want an OK button.
  $form_state['ok_button'] = TRUE;
  views_ui_standard_form_buttons($form, $form_state, 'views_ui_analyze_view_form');
  return $form;
}

/**
 * Submit handler for views_ui_analyze_view_form
 */
function views_ui_analyze_view_form_submit($form, &$form_state) {
  $form_state['redirect'] = 'admin/structure/views/view/' . $form_state['view']->name . '/configure';
}

/**
 * Form constructor callback to reorder displays on a view
 */
function views_ui_reorder_displays_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];

  $form['view'] = array('#type' => 'value', '#value' => $view);

  $form['#tree'] = TRUE;

  $last_display = end($view->display);

  foreach ($view->display as $display) {
    $form[$display->id] = array(
      'title'  => array('#markup' => check_plain($display->display_title)),
      'weight' => array(
        '#type' => 'weight',
        '#value' => $display->position,
        '#delta' => count($view->display),
        '#title' => t('Weight for @display', array('@display' => $display->display_title)),
        '#title_display' => 'invisible',
      ),
      '#tree' => TRUE,
      '#display' => $display,
      'removed' => array(
        '#type' => 'checkbox',
        '#id' => 'display-removed-' . $display->id,
        '#attributes' => array('class' => array('views-remove-checkbox')),
        '#default_value' => isset($display->deleted),
      ),
    );

    if (isset($display->deleted) && $display->deleted) {
      $form[$display->id]['deleted'] = array('#type' => 'value', '#value' => TRUE);
    }
    if ($display->id === 'default') {
      unset($form[$display->id]['weight']);
      unset($form[$display->id]['removed']);
    }

  }

  $form['#title'] = t('Displays Reorder');
  $form['#section'] = 'reorder';

  // Add javascript settings that will be added via $.extend for tabledragging
  $form['#js']['tableDrag']['reorder-displays']['weight'][0] = array(
    'target' => 'weight',
    'source' => NULL,
    'relationship' => 'sibling',
    'action' => 'order',
    'hidden' => TRUE,
    'limit' => 0,
  );

  $form['#action'] = url('admin/structure/views/nojs/reorder-displays/' . $view->name . '/' . $display_id);

  views_ui_standard_form_buttons($form, $form_state, 'views_ui_reorder_displays_form');

  return $form;
}

/**
 * Submit handler for rearranging display form
 */
function views_ui_reorder_displays_form_submit($form, &$form_state) {
  foreach($form_state['input'] as $display => $info) {
    // add each value that is a field with a weight to our list, but only if
    // it has had its 'removed' checkbox checked.
    if (is_array($info) && isset($info['weight']) && empty($info['removed'])) {
      $order[$display] = $info['weight'];
    }
  }

  // Sort the order array
  asort($order);

  // Fixing up positions
  $position = 2;

  foreach(array_keys($order) as $display) {
    $order[$display] = $position++;
  }

  // Setting up position and removing deleted displays
  $displays = $form_state['view']->display;
  foreach($displays as $display_id => $display) {
    // Don't touch the default !!!
    if ($display_id === 'default') {
      continue;
    }
    if (isset($order[$display_id])) {
      $form_state['view']->display[$display_id]->position = $order[$display_id];
    }
    else {
      $form_state['view']->display[$display_id]->deleted = TRUE;
    }
  }

  // Sorting back the display array as the position is not enough
  uasort($form_state['view']->display, function($display1, $display2) {
    if ($display1->position != $display2->position) {
      return $display1->position < $display2->position ? -1 : 1;
    }
    return 0;
  });

  // Store in cache
  views_ui_cache_set($form_state['view']);
  $form_state['redirect'] = array('admin/structure/views/view/' . $form_state['view']->name . '/configure', array('fragment' => 'views-tab-default'));
}

/**
 * Form builder to edit details of a view.
 */
function views_ui_edit_details_form($form, &$form_state) {
  $view = &$form_state['view'];

  $form['#title'] = t('View name and description');
  $form['#section'] = 'details';

  $form['details'] = array(
    '#theme_wrappers' => array('container'),
    '#attributes' => array('class' => array('scroll')),
  );
  $form['details']['human_name'] = array(
    '#type' => 'textfield',
    '#title' => t('Human-readable name'),
    '#description' => t('A descriptive human-readable name for this view. Spaces are allowed'),
    '#default_value' => $view->get_human_name(),
  );
  $form['details']['tag'] = array(
    '#type' => 'textfield',
    '#title' => t('View tags'),
    '#description' => t('Optionally, enter a comma delimited list of tags for this view to use in filtering and sorting views on the administrative page.'),
    '#default_value' => $view->tag,
    '#autocomplete_path' => 'admin/views/ajax/autocomplete/tag',
  );
  $form['details']['description'] = array(
    '#type' => 'textfield',
    '#title' => t('View description'),
    '#description' => t('This description will appear on the Views administrative UI to tell you what the view is about.'),
    '#default_value' => $view->description,
  );

  views_ui_standard_form_buttons($form, $form_state, 'views_ui_edit_details_form');
  return $form;
}

/**
 * Submit handler for views_ui_edit_details_form.
 */
function views_ui_edit_details_form_submit($form, &$form_state) {
  $view = $form_state['view'];
  foreach ($form_state['values'] as $key => $value) {
    // Only save values onto the view if they're actual view properties
    // (as opposed to 'op' or 'form_build_id').
    if (isset($form['details'][$key])) {
      $view->$key = $value;
    }
  }
  $form_state['#page_title'] = views_ui_edit_page_title($view);
  views_ui_cache_set($view);
}

/**
 * Form constructor callback to configure display of a view
 */
function views_ui_edit_display_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $section = $form_state['section'];

  if (!$view->set_display($display_id)) {
    views_ajax_error(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $display = &$view->display[$display_id];

  // Get form from the handler.
  $form['options'] = array(
    '#theme_wrappers' => array('container'),
    '#attributes' => array('class' => array('scroll')),
  );
  $display->handler->options_form($form['options'], $form_state);

  // The handler options form sets $form['#title'], which we need on the entire
  // $form instead of just the ['options'] section.
  $form['#title'] = $form['options']['#title'];
  unset($form['options']['#title']);

  // Move the override dropdown out of the scrollable section of the form.
  if (isset($form['options']['override'])) {
    $form['override'] = $form['options']['override'];
    unset($form['options']['override']);
  }

  $name = NULL;
  if (isset($form_state['update_name'])) {
    $name = $form_state['update_name'];
  }

  views_ui_standard_form_buttons($form, $form_state, 'views_ui_edit_display_form', $name);
  return $form;
}

/**
 * Validate handler for views_ui_edit_display_form
 */
function views_ui_edit_display_form_validate($form, &$form_state) {
  $display = &$form_state['view']->display[$form_state['display_id']];
  $display->handler->options_validate($form['options'], $form_state);

  if (form_get_errors()) {
    $form_state['rerender'] = TRUE;
  }
}

/**
 * Submit handler for views_ui_edit_display_form
 */
function views_ui_edit_display_form_submit($form, &$form_state) {
  $display = &$form_state['view']->display[$form_state['display_id']];
  $display->handler->options_submit($form, $form_state);

  views_ui_cache_set($form_state['view']);
}

/**
 * Override handler for views_ui_edit_display_form
 *
 * @TODO: Not currently used. Remove unless we implement an override toggle.
 */
function views_ui_edit_display_form_override($form, &$form_state) {
  $display = &$form_state['view']->display[$form_state['display_id']];
  $display->handler->options_override($form, $form_state);

  views_ui_cache_set($form_state['view']);
  $form_state['rerender'] = TRUE;
  $form_state['rebuild'] = TRUE;
}

/**
 * Form to config items in the views UI.
 */
function views_ui_config_type_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];

  $types = views_object_types();
  if (!$view->set_display($display_id)) {
    views_ajax_error(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $display = &$view->display[$display_id];
  $form['#title'] = t('Configure @type', array('@type' => $types[$type]['ltitle']));
  $form['#section'] = $display_id . 'config-item';

  if ($display->handler->defaultable_sections($types[$type]['plural'])) {
    $form_state['section'] = $types[$type]['plural'];
    views_ui_standard_display_dropdown($form, $form_state, $form_state['section']);
  }

  if (!empty($types[$type]['options']) && function_exists($types[$type]['options'])) {
    $options = $type . '_options';
    $form[$options] = array('#tree' => TRUE);
    $types[$type]['options']($form, $form_state);
  }

  $name = NULL;
  if (isset($form_state['update_name'])) {
    $name = $form_state['update_name'];
  }

  views_ui_standard_form_buttons($form, $form_state, 'views_ui_config_type_form', $name);
  return $form;
}

/**
 * Submit handler for type configuration form
 */
function views_ui_config_type_form_submit($form, &$form_state) {
  $types = views_object_types();
  $display = &$form_state['view']->display[$form_state['display_id']];

  // Store in cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Form to rearrange items in the views UI.
 */
function views_ui_rearrange_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];

  $types = views_object_types();
  if (!$view->set_display($display_id)) {
    views_ajax_error(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $display = &$view->display[$display_id];
  $form['#title'] = t('Rearrange @type', array('@type' => $types[$type]['ltitle']));
  $form['#section'] = $display_id . 'rearrange-item';

  if ($display->handler->defaultable_sections($types[$type]['plural'])) {
    $form_state['section'] = $types[$type]['plural'];
    views_ui_standard_display_dropdown($form, $form_state, $form_state['section']);
  }

  $count = 0;

  // Get relationship labels
  $relationships = array();
  foreach ($display->handler->get_handlers('relationship') as $id => $handler) {
    $relationships[$id] = $handler->label();
    $handlers = $display->handler->get_option('relationships');
    if ($handlers) {
      foreach ($handlers as $id => $info) {
        $handler = $display->handler->get_handler('relationship', $id);
        $relationships[$id] = $handler->label();
      }
    }
  }

  // Filters can now be grouped so we do a little bit extra:
  $groups = array();
  $grouping = FALSE;
  if ($type == 'filter') {
    $group_info = $view->display_handler->get_option('filter_groups');
    if (!empty($group_info['groups']) && count($group_info['groups']) > 1) {
      $grouping = TRUE;
      $groups = array(0 => array());
    }
  }

  foreach ($display->handler->get_option($types[$type]['plural']) as $id => $field) {
    $form['fields'][$id] = array('#tree' => TRUE);
    $form['fields'][$id]['weight'] = array(
      '#type' => 'textfield',
      '#default_value' => ++$count,
    );
    $handler = $display->handler->get_handler($type, $id);
    if ($handler) {
      $name = $handler->ui_name() . ' ' . $handler->admin_summary();
      if (!empty($field['relationship']) && !empty($relationships[$field['relationship']])) {
        $name = '(' . $relationships[$field['relationship']] . ') ' . $name;
      }

      $form['fields'][$id]['name'] = array(
        '#markup' => $name,
      );
    }
    else {
      $form['fields'][$id]['name'] = array('#markup' => t('Broken field @id', array('@id' => $id)));
    }
    $form['fields'][$id]['removed'] = array(
      '#type' => 'checkbox',
      '#id' => 'views-removed-' . $id,
      '#attributes' => array('class' => array('views-remove-checkbox')),
      '#default_value' => 0,
    );
  }

  // Add javascript settings that will be added via $.extend for tabledragging
  $form['#js']['tableDrag']['arrange']['weight'][0] = array(
    'target' => 'weight',
    'source' => NULL,
    'relationship' => 'sibling',
    'action' => 'order',
    'hidden' => TRUE,
    'limit' => 0,
  );

  $name = NULL;
  if (isset($form_state['update_name'])) {
    $name = $form_state['update_name'];
  }

  views_ui_standard_form_buttons($form, $form_state, 'views_ui_rearrange_form');
  return $form;
}

/**
 * Submit handler for rearranging form
 */
function views_ui_rearrange_form_submit($form, &$form_state) {
  $types = views_object_types();
  $display = &$form_state['view']->display[$form_state['display_id']];

  $old_fields = $display->handler->get_option($types[$form_state['type']]['plural']);
  $new_fields = $order = array();

  // Make an array with the weights
  foreach ($form_state['values'] as $field => $info) {
    // add each value that is a field with a weight to our list, but only if
    // it has had its 'removed' checkbox checked.
    if (is_array($info) && isset($info['weight']) && empty($info['removed'])) {
      $order[$field] = $info['weight'];
    }
  }

  // Sort the array
  asort($order);

  // Create a new list of fields in the new order.
  foreach (array_keys($order) as $field) {
    $new_fields[$field] = $old_fields[$field];
  }
  $display->handler->set_option($types[$form_state['type']]['plural'], $new_fields);

  // Store in cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Form to rearrange items in the views UI.
 */
function views_ui_rearrange_filter_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];

  $types = views_object_types();
  if (!$view->set_display($display_id)) {
    views_ajax_render(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $display = &$view->display[$display_id];
  $form['#title'] = check_plain($display->display_title) . ': ';
  $form['#title'] .= t('Rearrange @type', array('@type' => $types[$type]['ltitle']));
  $form['#section'] = $display_id . 'rearrange-item';

  if ($display->handler->defaultable_sections($types[$type]['plural'])) {
    $form_state['section'] = $types[$type]['plural'];
    views_ui_standard_display_dropdown($form, $form_state, $form_state['section']);
  }

  if (!empty($view->form_cache)) {
    $groups = $view->form_cache['groups'];
    $handlers = $view->form_cache['handlers'];
  }
  else {
    $groups = $display->handler->get_option('filter_groups');
    $handlers = $display->handler->get_option($types[$type]['plural']);
  }
  $count = 0;

  // Get relationship labels
  $relationships = array();
  foreach ($display->handler->get_handlers('relationship') as $id => $handler) {
    $relationships[$id] = $handler->label();
  }

  $group_options = array();

  /**
   * Filter groups is an array that contains:
   * array(
   *   'operator' => 'and' || 'or',
   *   'groups' => array(
   *     $group_id => 'and' || 'or',
   *   ),
   * );
   */

  $grouping = count(array_keys($groups['groups'])) > 1;

  $form['filter_groups']['#tree'] = TRUE;
  $form['filter_groups']['operator'] = array(
    '#type' => 'select',
    '#options' => array (
      'AND' => t('And'),
      'OR' => t('Or'),
    ),
    '#default_value' => $groups['operator'],
    '#attributes' => array(
      'class' => array('warning-on-change'),
    ),
    '#title' => t('Operator to use on all groups'),
    '#description' => t('Either "group 0 AND group 1 AND group 2" or "group 0 OR group 1 OR group 2", etc'),
    '#access' => $grouping,
  );

  $form['remove_groups']['#tree'] = TRUE;

  foreach ($groups['groups'] as $id => $group) {
    $form['filter_groups']['groups'][$id] = array(
      '#title' => t('Operator'),
      '#type' => 'select',
      '#options' => array(
        'AND' => t('And'),
        'OR' => t('Or'),
      ),
      '#default_value' => $group,
      '#attributes' => array(
        'class' => array('warning-on-change'),
      ),
      '#title_display' => 'before',
    );

    $form['remove_groups'][$id] = array(); // to prevent a notice
    if ($id != 1) {
      $form['remove_groups'][$id] = array(
        '#type' => 'submit',
        '#value' => t('Remove group @group', array('@group' => $id)),
        '#id' => "views-remove-group-$id",
        '#attributes' => array(
          'class' => array('views-remove-group'),
        ),
        '#group' => $id,
        '#ajax' => array(
          'path' => empty($form_state['path']) ? current_path() : $form_state['path'],
        ),
      );
    }
    $group_options[$id] = $id == 1 ? t('Default group') : t('Group @group', array('@group' => $id));
    $form['#group_renders'][$id] = array();
  }

  $form['#group_options'] = $group_options;
  $form['#groups'] = $groups;
  // We don't use get_handlers() because we want items without handlers to
  // appear and show up as 'broken' so that the user can see them.
  $form['filters'] = array('#tree' => TRUE);
  foreach ($handlers as $id => $field) {
    // If the group does not exist, move the filters to the default group.
    if (empty($field['group']) || empty($groups['groups'][$field['group']])) {
      $field['group'] = 1;
    }

    $handler = $display->handler->get_handler($type, $id);
    if ($grouping && $handler && !$handler->can_group()) {
      $field['group'] = 'ungroupable';
    }

    // If not grouping and the handler is set ungroupable, move it back to
    // the default group to prevent weird errors from having it be in its
    // own group:
    if (!$grouping && $field['group'] == 'ungroupable') {
      $field['group'] = 1;
    }

    // Place this item into the proper group for rendering.
    $form['#group_renders'][$field['group']][] = $id;

    $form['filters'][$id]['weight'] = array(
      '#type' => 'textfield',
      '#default_value' => ++$count,
      '#size' => 8,
    );
    $form['filters'][$id]['group'] = array(
      '#type' => 'select',
      '#options' => $group_options,
      '#default_value' => $field['group'],
      '#attributes' => array(
        'class' => array('views-region-select', 'views-region-' . $id),
      ),
      '#access' => $field['group'] !== 'ungroupable',
    );

    if ($handler) {
      $name = $handler->ui_name() . ' ' . $handler->admin_summary();
      if (!empty($field['relationship']) && !empty($relationships[$field['relationship']])) {
        $name = '(' . $relationships[$field['relationship']] . ') ' . $name;
      }

      $form['filters'][$id]['name'] = array(
        '#markup' => $name,
      );
    }
    else {
      $form['filters'][$id]['name'] = array('#markup' => t('Broken field @id', array('@id' => $id)));
    }
    $form['filters'][$id]['removed'] = array(
      '#type' => 'checkbox',
      '#id' => 'views-removed-' . $id,
      '#attributes' => array('class' => array('views-remove-checkbox')),
      '#default_value' => 0,
    );
  }

  if (isset($form_state['update_name'])) {
    $name = $form_state['update_name'];
  }

  views_ui_standard_form_buttons($form, $form_state, 'views_ui_rearrange_filter_form');
  $form['actions']['add_group'] = array(
    '#type' => 'submit',
    '#value' => t('Create new filter group'),
    '#id' => 'views-add-group',
    '#group' => 'add',
    '#ajax' => array(
      'path' => empty($form_state['path']) ? current_path() : $form_state['path'],
    ),
  );

  return $form;
}

/**
 * Submit handler for rearranging form
 */
function views_ui_rearrange_filter_form_submit($form, &$form_state) {
  views_include('utility');
  $types = views_object_types();
  $display = &$form_state['view']->display[$form_state['display_id']];
  $remember_groups = array();

  if (!empty($form_state['view']->form_cache)) {
    $old_fields = $form_state['view']->form_cache['handlers'];
  }
  else {
    $old_fields = $display->handler->get_option($types[$form_state['type']]['plural']);
  }

  // Ensure defaults.
  $form_state['values'] += array(
    'filter_groups' => array(),
    'filters' => array(),
  );

  $groups = $form_state['values']['filter_groups'];
  // Whatever button was clicked, re-calculate field information.
  $new_fields = $order = array();

  // Make an array with the weights
  foreach ($form_state['values']['filters'] as $field => $info) {
    // add each value that is a field with a weight to our list, but only if
    // it has had its 'removed' checkbox checked.
    if (is_array($info) && empty($info['removed'])) {
      if (isset($info['weight'])) {
        $order[$field] = $info['weight'];
      }

      if (isset($info['group'])) {
        $old_fields[$field]['group'] = $info['group'];
        $remember_groups[$info['group']][] = $field;
      }
    }
  }

  // Sort the array
  asort($order);

  // Create a new list of fields in the new order.
  foreach (array_keys($order) as $field) {
    $new_fields[$field] = $old_fields[$field];
  }

  // If the #group property is set on the clicked button, that means we are
  // either adding or removing a group, not actually updating the filters.
  if (!empty($form_state['clicked_button']['#group'])) {
    if ($form_state['clicked_button']['#group'] == 'add') {
      // Add a new group
      $groups['groups'][] = 'AND';
    }
    else {
      // Renumber groups above the removed one down.
      foreach (array_keys($groups['groups']) as $group_id) {
        if ($group_id >= $form_state['clicked_button']['#group']) {
          $old_group = $group_id + 1;
          if (isset($groups['groups'][$old_group])) {
            $groups['groups'][$group_id] = $groups['groups'][$old_group];
            if (isset($remember_groups[$old_group])) {
              foreach ($remember_groups[$old_group] as $id) {
                $new_fields[$id]['group'] = $group_id;
              }
            }
          }
          else {
            // If this is the last one, just unset it.
            unset($groups['groups'][$group_id]);
          }
        }
      }
    }
    // Update our cache with values so that cancel still works the way
    // people expect.
    $form_state['view']->form_cache = array(
      'key' => 'rearrange-filter',
      'groups' => $groups,
      'handlers' => $new_fields,
    );

    // Return to this form except on actual Update.
    views_ui_add_form_to_stack('rearrange-filter', $form_state['view'], $form_state['display_id'], array($form_state['type']));
  }
  else {
    // The actual update button was clicked. Remove the empty groups, and
    // renumber them sequentially.
    ksort($remember_groups);
    $groups['groups'] = views_array_key_plus(array_values(array_intersect_key($groups['groups'], $remember_groups)));
    // Change the 'group' key on each field to match. Here, $mapping is an
    // array whose keys are the old group numbers and whose values are the new
    // (sequentially numbered) ones.
    $mapping = array_flip(views_array_key_plus(array_keys($remember_groups)));
    foreach ($new_fields as &$new_field) {
      $new_field['group'] = $mapping[$new_field['group']];
    }

    // Write the changed handler values.
    $display->handler->set_option($types[$form_state['type']]['plural'], $new_fields);
    $display->handler->set_option('filter_groups', $groups);
    if (isset($form_state['view']->form_cache)) {
      unset($form_state['view']->form_cache);
    }
  }

  // Store in cache.
  views_ui_cache_set($form_state['view']);
}

/**
 * Form to add_item items in the views UI.
 */
function views_ui_add_item_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];

  $form = array(
    'options' => array(
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('scroll'), 'data-backdrop-views-scroll' => TRUE),
    ),
  );

  if (!$view->set_display($display_id)) {
    views_ajax_error(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $display = &$view->display[$display_id];

  $types = views_object_types();
  $ltitle = $types[$type]['ltitle'];
  $section = $types[$type]['plural'];

  if (!empty($types[$type]['type'])) {
    $type = $types[$type]['type'];
  }

  $form['#title'] = t('Add @type', array('@type' => $ltitle));
  $form['#section'] = $display_id . 'add-item';


  // Add the display override dropdown.
  views_ui_standard_display_dropdown($form, $form_state, $section);

  // Figure out all the base tables allowed based upon what the relationships provide.
  $base_tables = $view->get_base_tables();
  $options = views_fetch_fields(array_keys($base_tables), $type, $display->handler->use_group_by());

  if (!empty($options)) {
    $form['options']['controls'] = array(
      '#theme_wrappers' => array('container'),
      '#id' => 'views-filterable-options-controls',
      '#attributes' => array('class' => array('container-inline')),
    );
    $form['options']['controls']['options_search'] = array(
      '#type' => 'textfield',
      '#title' => t('Search'),
    );

    $groups = array('all' => t('- All -'));
    $form['options']['controls']['group'] = array(
      '#type' => 'select',
      '#title' => t('Filter'),
      '#options' => array(),
    );

    $form['options']['name'] = array(
      '#prefix' => '<div class="views-radio-box form-checkboxes views-filterable-options">',
      '#suffix' => '</div>',
      '#tree' => TRUE,
      '#default_value' => 'all',
    );

    // Group options first to simplify the DOM objects that Views
    // dependent JS will act upon.
    $grouped_options = array();
    foreach ($options as $key => $option) {
      $group = preg_replace('/[^a-z0-9]/', '-', strtolower($option['group']));
      $groups[$group] = $option['group'];
      $grouped_options[$group][$key] = $option;
      if (!empty($option['aliases']) && is_array($option['aliases'])) {
        foreach ($option['aliases'] as $id => $alias) {
          if (empty($alias['base']) || !empty($base_tables[$alias['base']])) {
            $copy = $option;
            $copy['group'] = $alias['group'];
            $copy['title'] = $alias['title'];
            if (isset($alias['help'])) {
              $copy['help'] = $alias['help'];
            }

            $group = preg_replace('/[^a-z0-9]/', '-', strtolower($copy['group']));
            $groups[$group] = $copy['group'];
            $grouped_options[$group][$key . '$' . $id] = $copy;
          }
        }
      }
    }

    foreach ($grouped_options as $group => $group_options) {
      $form['options']['name'][$group . '_start']['#markup'] = '<div class="views-filterable-group views-filterable-group-' . $group . '">';
      $zebra = 0;
      foreach ($group_options as $key => $option) {
        $zebra_class = ($zebra % 2) ? 'odd' : 'even';
        $form['options']['name'][$key] = array(
          '#type' => 'checkbox',
          '#title' => t('!group: !field', array('!group' => check_plain($option['group']), '!field' => check_plain($option['title']))),
          '#description' => filter_xss_admin($option['help']),
          '#return_value' => $key,
          '#prefix' => "<div class='$zebra_class filterable-option'>",
          '#suffix' => '</div>',
        );
        $zebra++;
      }
      $form['options']['name'][$group . '_end']['#markup'] = '</div>';
    }

    $form['options']['controls']['group']['#options'] = $groups;
  }
  else {
    $form['options']['markup'] = array(
      '#markup' => '<div class="form-item">' . t('There are no @types available to add.', array('@types' =>  $ltitle)) . '</div>',
    );
  }
  // Add a div to show the selected items
  $form['selected'] = array(
    '#type' => 'item',
    '#markup' => '<div class="views-selected-options"></div>',
    '#title' => t('Selected') . ':',
    '#theme_wrappers' => array('form_element', 'views_container'),
    '#attributes' => array(
      'class' => array('container-inline', 'views-add-form-selected'),
      'data-views-offset' => 'bottom',
    ),
  );
  views_ui_standard_form_buttons($form, $form_state, 'views_ui_add_item_form', t('Add and configure @types', array('@types' => $ltitle)));

  // Remove the default submit function.
  $form['actions']['submit']['#submit'] = array_diff($form['actions']['submit']['#submit'], array('views_ui_standard_submit'));
  $form['actions']['submit']['#submit'][] = 'views_ui_add_item_form_submit';

  return $form;
}

/**
 * Submit handler for adding new item(s) to a view.
 */
function views_ui_add_item_form_submit($form, &$form_state) {
  $type = $form_state['type'];
  $types = views_object_types();
  $section = $types[$type]['plural'];

  // Handle the override select.
  list($was_defaulted, $is_defaulted) = views_ui_standard_override_values($form, $form_state);
  if ($was_defaulted && !$is_defaulted) {
    // We were using the default display's values, but we're now overriding
    // the default display and saving values specific to this display.
    $display = &$form_state['view']->display[$form_state['display_id']];
    // set_override toggles the override of this section.
    $display->handler->set_override($section);
  }
  elseif (!$was_defaulted && $is_defaulted) {
    // We used to have an override for this display, but the user now wants
    // to go back to the default display.
    // Overwrite the default display with the current form values, and make
    // the current display use the new default values.
    $display = &$form_state['view']->display[$form_state['display_id']];
    // options_override toggles the override of this section.
    $display->handler->set_override($section);
  }

  if (!empty($form_state['values']['name']) && is_array($form_state['values']['name'])) {
    // Loop through each of the items that were checked and add them to the view.
    foreach (array_keys(array_filter($form_state['values']['name'])) as $field) {
      list($table, $field) = explode('.', $field, 2);

      if ($cut = strpos($field, '$')) {
        $field = substr($field, 0, $cut);
      }
      $id = $form_state['view']->add_item($form_state['display_id'], $type, $table, $field);

      // check to see if we have group by settings
      $key = $type;
      // Footer,header and empty text have a different internal handler type(area).
      if (isset($types[$type]['type'])) {
        $key = $types[$type]['type'];
      }
      $handler = views_get_handler($table, $field, $key);
      if ($form_state['view']->display_handler->use_group_by() && $handler->use_group_by()) {
        views_ui_add_form_to_stack('config-item-group', $form_state['view'], $form_state['display_id'], array($type, $id));
      }

      // check to see if this type has settings, if so add the settings form first
      if ($handler && $handler->has_extra_options()) {
        views_ui_add_form_to_stack('config-item-extra', $form_state['view'], $form_state['display_id'], array($type, $id));
      }
      // Then add the form to the stack
      views_ui_add_form_to_stack('config-item', $form_state['view'], $form_state['display_id'], array($type, $id));
    }
  }

  if (isset($form_state['view']->form_cache)) {
    unset($form_state['view']->form_cache);
  }

  // Store in cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Override handler for views_ui_edit_display_form
 */
function views_ui_config_item_form_build_group($form, &$form_state) {
  $item = &$form_state['handler']->options;
  // flip. If the filter was a group, set back to a standard filter.
  $item['is_grouped'] = empty($item['is_grouped']);

  // If necessary, set new defaults:
  if ($item['is_grouped']) {
    $form_state['handler']->build_group_options();
  }

  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], $item);

  views_ui_add_form_to_stack($form_state['form_key'], $form_state['view'], $form_state['display_id'], array($form_state['type'], $form_state['id']), TRUE, TRUE);

  views_ui_cache_set($form_state['view']);
  $form_state['rerender'] = TRUE;
  $form_state['rebuild'] = TRUE;
  $form_state['force_build_group_options'] = TRUE;
}

/**
 * Add a new group to the exposed filter groups.
 */
function views_ui_config_item_form_add_group($form, &$form_state) {
  $item =& $form_state['handler']->options;

  // Add a new row.
  $item['group_info']['group_items'][] = array();

  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], $item);

  views_ui_cache_set($form_state['view']);
  $form_state['rerender'] = TRUE;
  $form_state['rebuild'] = TRUE;
  $form_state['force_build_group_options'] = TRUE;
}

/**
 * Form to config_item items in the views UI.
 */
function views_ui_config_item_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];
  $id = $form_state['id'];

  $form = array(
    'options' => array(
      '#tree' => TRUE,
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('scroll'), 'data-backdrop-views-scroll' => TRUE),
    ),
  );
  if (!$view->set_display($display_id)) {
    views_ajax_error(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $item = $view->get_item($display_id, $type, $id);

  if ($item) {
    $handler = $view->display_handler->get_handler($type, $id);
    if (empty($handler)) {
      $form['markup'] = array('#markup' => t("Error: handler for @table > @field doesn't exist!", array('@table' => $item['table'], '@field' => $item['field'])));
    }
    else {
      $types = views_object_types();

      // If this item can come from the default display, show a dropdown
      // that lets the user choose which display the changes should apply to.
      if ($view->display_handler->defaultable_sections($types[$type]['plural'])) {
        $form_state['section'] = $types[$type]['plural'];
        views_ui_standard_display_dropdown($form, $form_state, $form_state['section']);
      }

      // A whole bunch of code to figure out what relationships are valid for
      // this item.
      $relationships = $view->display_handler->get_option('relationships');
      $relationship_options = array();

      foreach ($relationships as $relationship) {
        // relationships can't link back to self. But also, due to ordering,
        // relationships can only link to prior relationships.
        if ($type == 'relationship' && $id == $relationship['id']) {
          break;
        }
        $relationship_handler = views_get_handler($relationship['table'], $relationship['field'], 'relationship');
        // ignore invalid/broken relationships.
        if (empty($relationship_handler)) {
          continue;
        }

        // If this relationship is valid for this type, add it to the list.
        $data = views_fetch_data($relationship['table']);
        $base = $data[$relationship['field']]['relationship']['base'];
        $base_fields = views_fetch_fields($base, $form_state['type'], $view->display_handler->use_group_by());
        if (isset($base_fields[$item['table'] . '.' . $item['field']])) {
          $relationship_handler->init($view, $relationship);
          $relationship_options[$relationship['id']] = $relationship_handler->label();
        }
      }

      if (!empty($relationship_options)) {
        // Make sure the existing relationship is even valid. If not, force
        // it to none.
        $base_fields = views_fetch_fields($view->base_table, $form_state['type'], $view->display_handler->use_group_by());
        if (isset($base_fields[$item['table'] . '.' . $item['field']])) {
          $relationship_options = array_merge(array('none' => t('Do not use a relationship')), $relationship_options);
        }
        $rel = empty($item['relationship']) ? 'none' : $item['relationship'];
        if (empty($relationship_options[$rel])) {
          // Pick the first relationship.
          $rel = key($relationship_options);
          // We want this relationship option to get saved even if the user
          // skips submitting the form.
          $view->set_item_option($display_id, $type, $id, 'relationship', $rel);
          $temp_view = $view->clone_view();
          views_ui_cache_set($temp_view);
        }

        $form['options']['relationship'] = array(
          '#type' => 'select',
          '#title' => t('Relationship'),
          '#options' => $relationship_options,
          '#default_value' => $rel,
          '#weight' => -500,
        );
      }
      else {
        $form['options']['relationship'] = array(
          '#type' => 'value',
          '#value' => 'none',
        );
      }

      $form['#title'] = t('Configure @type: @item', array('@type' => $types[$type]['lstitle'], '@item' => $handler->ui_name()));

      if (!empty($handler->definition['help'])) {
        $form['options']['form_description'] = array(
          '#type' => 'help',
          '#markup' => $handler->definition['help'],
          '#theme_wrappers' => array('container'),
          '#attributes' => array('class' => array('form-item description')),
          '#weight' => -1000,
        );
      }

      $form['#section'] = $display_id . '-' . $type . '-' . $id;

      // Get form from the handler.
      $handler->options_form($form['options'], $form_state);
      $form_state['handler'] = &$handler;

      // Allow other modules to alter the formatter settings form.
      if ($handler instanceof views_handler_field_field) {
        $context = array(
          'module' => $handler->field_info['module'],
          'formatter' => $handler->field_info['type'],
          'field' => field_info_field($handler->options['field']),
          'instance' => $handler->instance,
          'view_mode' => '_custom', // Same view mode as field_view_field().
          'form' => $form,
          'form_state' => $form_state,
        );
        backdrop_alter('field_formatter_settings_form', $form['options']['settings'], $context);
      }
    }

    $name = NULL;
    if (isset($form_state['update_name'])) {
      $name = $form_state['update_name'];
    }

    views_ui_standard_form_buttons($form, $form_state, 'views_ui_config_item_form', $name, t('Remove'), 'remove');
    // Only validate the override values, because this values are required for
    // the override selection.
    $form['actions']['remove']['#limit_validation_errors'] = array(array('override'));
  }

  return $form;
}

/**
 * Submit handler for configing new item(s) to a view.
 */
function views_ui_config_item_form_validate($form, &$form_state) {
  $form_state['handler']->options_validate($form['options'], $form_state);

  if (form_get_errors()) {
    $form_state['rerender'] = TRUE;
  }
}

/**
 * A submit handler that is used for storing temporary items when using
 * multi-step changes, such as ajax requests.
 */
function views_ui_config_item_form_submit_temporary($form, &$form_state) {
  // Run it through the handler's submit function.
  $form_state['handler']->options_submit($form['options'], $form_state);
  $item = $form_state['handler']->options;
  $types = views_object_types();

  // For footer/header $handler_type is area but $type is footer/header.
  // For all other handle types it's the same.
  $handler_type = $type = $form_state['type'];
  if (!empty($types[$type]['type'])) {
    $handler_type = $types[$type]['type'];
  }

  $override = NULL;
  if ($form_state['view']->display_handler->use_group_by() && !empty($item['group_type'])) {
    if (empty($form_state['view']->query)) {
      $form_state['view']->init_query();
    }
    $aggregate = $form_state['view']->query->get_aggregation_info();
    if (!empty($aggregate[$item['group_type']]['handler'][$type])) {
      $override = $aggregate[$item['group_type']]['handler'][$type];
    }
  }

  // Create a new handler and unpack the options from the form onto it. We
  // can use that for storage.
  $handler = views_get_handler($item['table'], $item['field'], $handler_type, $override);
  $handler->init($form_state['view'], $item);


  // Add the incoming options to existing options because items using
  // the extra form may not have everything in the form here.
  $options = $form_state['values']['options'] + $form_state['handler']->options;

  // This unpacks only options that are in the definition, ensuring random
  // extra stuff on the form is not sent through.
  $handler->unpack_options($handler->options, $options, NULL, FALSE);

  // Store the item back on the view
  $form_state['view']->temporary_options[$type][$form_state['id']] = $handler->options;

  // @todo: Figure out whether views_ui_ajax_form is perhaps the better place to fix the issue.
  // views_ui_ajax_form() drops the current form from the stack, even if it's an #ajax.
  // So add the item back to the top of the stack.
  views_ui_add_form_to_stack($form_state['form_key'], $form_state['view'], $form_state['display_id'], array($type, $item['id']), TRUE);

  $form_state['rerender'] = TRUE;
  $form_state['rebuild'] = TRUE;
  // Write to cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Submit handler for configing new item(s) to a view.
 */
function views_ui_config_item_form_submit($form, &$form_state) {
  // Run it through the handler's submit function.
  $form_state['handler']->options_submit($form['options'], $form_state);
  $item = $form_state['handler']->options;
  $types = views_object_types();

  // For footer/header $handler_type is area but $type is footer/header.
  // For all other handle types it's the same.
  $handler_type = $type = $form_state['type'];
  if (!empty($types[$type]['type'])) {
    $handler_type = $types[$type]['type'];
  }

  $override = NULL;
  if ($form_state['view']->display_handler->use_group_by() && !empty($item['group_type'])) {
    if (empty($form_state['view']->query)) {
      $form_state['view']->init_query();
    }
    $aggregate = $form_state['view']->query->get_aggregation_info();
    if (!empty($aggregate[$item['group_type']]['handler'][$type])) {
      $override = $aggregate[$item['group_type']]['handler'][$type];
    }
  }

  // Create a new handler and unpack the options from the form onto it. We
  // can use that for storage.
  $handler = views_get_handler($item['table'], $item['field'], $handler_type, $override);
  $handler->init($form_state['view'], $item);


  // Add the incoming options to existing options because items using
  // the extra form may not have everything in the form here.
  $options = $form_state['values']['options'] + $form_state['handler']->options;

  // This unpacks only options that are in the definition, ensuring random
  // extra stuff on the form is not sent through.
  $handler->unpack_options($handler->options, $options, NULL, FALSE);

  // Store the item back on the view
  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], $handler->options);

  // Ensure any temporary options are removed.
  if (isset($form_state['view']->temporary_options[$type][$form_state['id']])) {
    unset($form_state['view']->temporary_options[$type][$form_state['id']]);
  }

  // Write to cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Form to config_item items in the views UI.
 */
function views_ui_config_item_group_form($type, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];
  $id = $form_state['id'];

  $form = array(
    'options' => array(
      '#tree' => TRUE,
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('scroll')),
    ),
  );
  if (!$view->set_display($display_id)) {
    views_ajax_render(t('Invalid display id @display', array('@display' => $display_id)));
  }

  $view->init_query();

  $item = $view->get_item($display_id, $type, $id);

  if ($item) {
    $handler = $view->display_handler->get_handler($type, $id);
    if (empty($handler)) {
      $form['markup'] = array('#markup' => t("Error: handler for @table > @field doesn't exist!", array('@table' => $item['table'], '@field' => $item['field'])));
    }
    else {
      $handler->init($view, $item);
      $types = views_object_types();

      $form['#title'] = t('Configure group settings for @type %item', array('@type' => $types[$type]['lstitle'], '%item' => $handler->ui_name()));

      $handler->groupby_form($form['options'], $form_state);
      $form_state['handler'] = &$handler;
    }

    views_ui_standard_form_buttons($form, $form_state, 'views_ui_config_item_group_form');
  }
  return $form;
}

/**
 * Submit handler for configing group settings on a view.
 */
function views_ui_config_item_group_form_submit($form, &$form_state) {
  $item =& $form_state['handler']->options;
  $type = $form_state['type'];
  $id = $form_state['id'];

  $handler = views_get_handler($item['table'], $item['field'], $type);
  $handler->init($form_state['view'], $item);

  $handler->groupby_form_submit($form, $form_state);

  // Store the item back on the view
  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], $item);

  // Write to cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Submit handler for removing an item from a view
 */
function views_ui_config_item_form_remove($form, &$form_state) {
  // Store the item back on the view
  list($was_defaulted, $is_defaulted) = views_ui_standard_override_values($form, $form_state);
  // If the display selection was changed toggle the override value.
  if ($was_defaulted != $is_defaulted) {
    $display =& $form_state['view']->display[$form_state['display_id']];
    $display->handler->options_override($form, $form_state);
  }
  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], NULL);

  // Write to cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Override handler for views_ui_edit_display_form
 */
function views_ui_config_item_form_expose($form, &$form_state) {
  $item = &$form_state['handler']->options;
  // flip
  $item['exposed'] = empty($item['exposed']);

  // If necessary, set new defaults:
  if ($item['exposed']) {
    $form_state['handler']->expose_options();
  }

  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], $item);

  views_ui_add_form_to_stack($form_state['form_key'], $form_state['view'], $form_state['display_id'], array($form_state['type'], $form_state['id']), TRUE, TRUE);

  views_ui_cache_set($form_state['view']);
  $form_state['rerender'] = TRUE;
  $form_state['rebuild'] = TRUE;
  $form_state['force_expose_options'] = TRUE;
}

/**
 * Form to config_item items in the views UI.
 */
function views_ui_config_item_extra_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];
  $id = $form_state['id'];

  $form = array(
    'options' => array(
      '#tree' => TRUE,
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('scroll')),
    ),
  );
  if (!$view->set_display($display_id)) {
    views_ajax_error(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $item = $view->get_item($display_id, $type, $id);

  if ($item) {
    $handler = $view->display_handler->get_handler($type, $id);
    if (empty($handler)) {
      $form['markup'] = array('#markup' => t("Error: handler for @table > @field doesn't exist!", array('@table' => $item['table'], '@field' => $item['field'])));
    }
    else {
      $handler->init($view, $item);
      $types = views_object_types();

      $form['#title'] = t('Configure extra settings for @type %item', array('@type' => $types[$type]['lstitle'], '%item' => $handler->ui_name()));

      $form['#section'] = $display_id . '-' . $type . '-' . $id;

      // Get form from the handler.
      $handler->extra_options_form($form['options'], $form_state);
      $form_state['handler'] = &$handler;
    }

    views_ui_standard_form_buttons($form, $form_state, 'views_ui_config_item_extra_form');
  }
  return $form;
}

/**
 * Validation handler for configing new item(s) to a view.
 */
function views_ui_config_item_extra_form_validate($form, &$form_state) {
  $form_state['handler']->extra_options_validate($form['options'], $form_state);
}

/**
 * Submit handler for configing new item(s) to a view.
 */
function views_ui_config_item_extra_form_submit($form, &$form_state) {
  // Run it through the handler's submit function.
  $form_state['handler']->extra_options_submit($form['options'], $form_state);
  $item = $form_state['handler']->options;

  // Store the data we're given.
  foreach ($form_state['values']['options'] as $key => $value) {
    $item[$key] = $value;
  }

  // Store the item back on the view
  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], $item);

  // Write to cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Form to config_style items in the views UI.
 */
function views_ui_config_style_form($form, &$form_state) {
  $view = &$form_state['view'];
  $display_id = $form_state['display_id'];
  $type = $form_state['type'];
  $id = $form_state['id'];

  $form = array(
    'options' => array(
      '#tree' => TRUE,
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('scroll')),
    ),
  );
  if (!$view->set_display($display_id)) {
    views_ajax_error(t('Invalid display id @display', array('@display' => $display_id)));
  }
  $item = $view->get_item($display_id, $type, $id);

  if ($item) {
    $handler = views_get_handler($item['table'], $item['field'], $type);
    if (empty($handler)) {
      $form['markup'] = array('#markup' => t("Error: handler for @table > @field doesn't exist!", array('@table' => $item['table'], '@field' => $item['field'])));
    }
    else {
      $handler->init($view, $item);
      $types = views_object_types();

      $form['#title'] = t('Configure summary style for @type %item', array('@type' => $types[$type]['lstitle'], '%item' => $handler->ui_name()));

      $form['#section'] = $display_id . '-' . $type . '-style-options';

      $plugin = views_get_plugin('style', $handler->options['style_plugin']);
      if ($plugin) {
        $form['style_options'] = array(
          '#tree' => TRUE,
        );
        $plugin->init($view, $view->display[$display_id], $handler->options['style_options']);

        $plugin->options_form($form['style_options'], $form_state);
      }

      $form_state['handler'] = &$handler;
    }

    views_ui_standard_form_buttons($form, $form_state, 'views_ui_config_style_form');
  }
  return $form;
}

/**
 * Submit handler for configing new item(s) to a view.
 */
function views_ui_config_style_form_submit($form, &$form_state) {
  // Run it through the handler's submit function.
  $form_state['handler']->options_submit($form['style_options'], $form_state);
  $item = $form_state['handler']->options;

  // Store the data we're given.
  $item['style_options'] = $form_state['values']['style_options'];

  // Store the item back on the view
  $form_state['view']->set_item($form_state['display_id'], $form_state['type'], $form_state['id'], $item);

  // Write to cache
  views_ui_cache_set($form_state['view']);
}

/**
 * Form builder for the admin display defaults page.
 */
function views_ui_admin_settings_basic() {
  $form = array();
  $form['#attached']['css'] = views_ui_get_admin_css();
  $config = config('views_ui.settings');

  $form['wizard'] = array(
    '#type' => 'fieldset',
    '#title' => t("'Add view' wizard"),
  );
  $form['wizard']['wizard_default_display'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Display types to include by default'),
    '#description' => t("These display types will be selected by default when a new view is created using the '!add_view' wizard.", array('!add_view' => l(t('Add View'), 'admin/structure/views/add'))),
    '#options' => array(
      'page' => t('Page'),
      'block' => t('Block'),
    ),
    '#default_value' => $config->get('wizard_default_display'),
  );

  $form['basic'] = array(
    '#type' => 'fieldset',
    '#title' => t('Views UI settings'),
  );
  $form['basic']['show_default_display'] = array(
    '#type' => 'checkbox',
    '#title' => t('Always show the <em>Default</em> display'),
    '#description' => t('Show the <em>Default</em> (i.e. default) display, which is otherwise hidden.'),
    '#default_value' => $config->get('show_default_display'),
  );
  $form['basic']['display_embed'] = array(
    '#type' => 'checkbox',
    '#title' => t('Allow <em>embed</em> displays to be created via the UI'),
    '#description' => t('Enables the <em>embed</em> type of display. Embed displays can be used in code via <a href="@api_link"><code>views_embed_view()</code></a>. Embedded displays will still work even if this setting is disabled.', array('@api_link' => url('https://docs.backdropcms.org/api/backdrop/core%21modules%21views%21views.module/function/views_embed_view'))),
    '#default_value' => $config->get('display_embed'),
  );
  $options = array();
  foreach (list_themes() as $name => $theme) {
    if ($theme->status) {
      $options[$name] = $theme->info['name'];
    }
  }
  $form['basic']['custom_theme'] = array(
    '#type' => 'select',
    '#title' => t('Custom admin theme for the Views UI'),
    '#options' => array('_default' => t('- Use default -')) + $options,
    '#default_value' => $config->get('custom_theme'),
    '#description' => t('In some cases you might want to select a different admin theme for the Views UI.')
  );
  $form['basic']['exposed_filter_any_label'] = array(
    '#type' => 'select',
    '#title' => t('Label for "Any" value on non-required single-select exposed filters'),
    '#options' => array('old_any' => '<Any>', 'new_any' => t('- Any -')),
    '#default_value' => config_get('views.settings', 'exposed_filter_any_label'),
  );

  $form['live_preview'] = array(
    '#type' => 'fieldset',
    '#title' => t('Live preview settings'),
  );
  $form['live_preview']['always_live_preview'] = array(
    '#type' => 'checkbox',
    '#title' => t('Automatically update preview on changes'),
    '#default_value' => $config->get('always_live_preview'),
  );
  $form['live_preview']['show_preview_information'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show information and statistics about the view during live preview'),
    '#default_value' => $config->get('show_preview_information'),
  );
  // Set a common variable used for #states on the following elements.
  $preview_checked = array(
    'visible' => array(
      ':input[name="show_preview_information"]' => array('checked' => TRUE),
    ),
  );
  $form['live_preview']['show_sql_query_where'] = array(
    '#type' => 'radios',
    '#title' => t('Statistics location'),
    '#options' => array(
      'above' => t('Above the preview'),
      'below' => t('Below the preview'),
    ),
    '#default_value' => $config->get('show_sql_query_where'),
    '#states' => $preview_checked,
  );
  $form['live_preview']['show_sql_query'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show the SQL query'),
    '#default_value' => $config->get('show_sql_query'),
    '#states' => $preview_checked,
  );
  $form['live_preview']['show_performance_statistics'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show performance statistics'),
    '#default_value' => $config->get('show_performance_statistics'),
    '#states' => $preview_checked,
  );
  $form['live_preview']['show_additional_queries'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show other queries run during render during live preview'),
    '#description' => t("Backdrop has the potential to run many queries while a view is being rendered. Checking this box will display every query run during view render as part of the live preview."),
    '#default_value' => config_get('views.settings', 'show_additional_queries'),
    '#states' => array(
      'visible' => array(
        ':input[name="show_preview_information"]' => array('checked' => TRUE),
      ),
    ),
  );

  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save settings'),
  );

  return $form;
}

/**
 * Submit handler for views_ui_admin_settings_basic().
 */
function views_ui_admin_settings_basic_submit($form, $form_state) {
  // Views UI saves some Views module settings.
  $views_config = config('views.settings');
  $views_config->set('exposed_filter_any_label', $form_state['values']['exposed_filter_any_label']);
  $views_config->set('show_additional_queries', $form_state['values']['show_additional_queries']);
  $views_config->save();
  unset($form_state['values']['exposed_filter_any_label']);
  unset($form_state['values']['show_additional_queries']);

  form_state_values_clean($form_state);
  $config = config('views_ui.settings');
  $config->setData($form_state['values']);
  $config->save();
  backdrop_set_message(t('The configuration options have been saved.'));
}

/**
 * Form builder for the advanced admin settings page.
 */
function views_ui_admin_settings_advanced() {
  $form = array();
  $form['#attached']['css'] = views_ui_get_admin_css();
  $config = config('views.settings');

  // Set the "any" label as a value so it is included in the saved config.
  $form['exposed_filter_any_label'] = array(
    '#type' => 'value',
    '#value' => $config->get('exposed_filter_any_label'),
  );

  $form['cache'] = array(
    '#type' => 'fieldset',
    '#title' => t('Caching'),
    '#access' => user_access('flush caches'),
  );

  $form['cache']['clear_cache'] = array(
    '#type' => 'submit',
    '#value' => t("Clear Views' cache"),
    '#submit' => array('views_ui_tools_clear_cache'),
  );

  $form['debug'] = array(
    '#type' => 'fieldset',
    '#title' => t('Debugging'),
  );

  $form['debug']['sql_signature'] = array(
    '#type' => 'checkbox',
    '#title' => t('Add Views signature to all SQL queries'),
    '#description' => t("All Views-generated queries will include the name of the views and display 'view-name:display-name' as a string  at the end of the SELECT clause. This makes identifying Views queries in database server logs simpler, but should only be used when troubleshooting."),
    '#default_value' => $config->get('sql_signature'),
  );

  $form['debug']['devel_output'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enable views performance statistics/debug messages via the Devel module'),
    '#description' => t("Check this to enable some Views query and performance statistics/debug messages <em>if Devel is installed</em>."),
    '#default_value' => $config->get('devel_output'),
  );

  $form['locale'] = array(
    '#type' => 'fieldset',
    '#title' => t('Localization'),
  );

  $form['locale']['views_localization_plugin'] = array(
    '#type' => 'radios',
    '#title' => t('Translation method'),
    '#options' => views_fetch_plugin_names('localization', NULL, array()),
    '#default_value' => views_get_localization_plugin(),
    '#description' => t('Select a translation method to use for Views data like header, footer, and empty text.'),
  );

  $regions = array();
  $regions['watchdog'] = t('Watchdog');

  $form['debug']['devel_region'] = array(
    '#type' => 'select',
    '#title' => t('Page region to output performance statistics/debug messages'),
    '#default_value' => $config->get('devel_region'),
    '#options' => $regions,
    '#states' => array(
      'visible' => array(
        ':input[name="views_devel_output"]' => array('checked' => TRUE),
      ),
    ),
  );

  $options = views_fetch_plugin_names('display_extender');
  $form['extenders'] = array(
    '#type' => 'fieldset',
    '#access' => count($options) > 0,
  );
  $form['extenders']['display_extenders'] = array(
    '#title' => t('Display extenders'),
    '#default_value' => views_get_enabled_display_extenders(),
    '#options' => $options,
    '#type' => 'checkboxes',
    '#description' => t('Select extensions of the views interface.')
  );

  $form['field_rewrite_elements'] = array(
    '#type' => 'value',
    '#value' => $config->get('field_rewrite_elements'),
  );

  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save settings'),
  );

  return $form;
}

/**
 * Submit handler for views_ui_admin_settings_advanced().
 */
function views_ui_admin_settings_advanced_submit($form, $form_state) {
  form_state_values_clean($form_state);

  // Note that all settings on this page affect Views module, not Views UI.
  $config = config('views.settings');
  $config->setData($form_state['values']);
  $config->save();
  backdrop_set_message(t('The configuration options have been saved.'));
}

/**
 * Submit hook to clear the views cache.
 */
function views_ui_tools_clear_cache() {
  views_invalidate_cache();
  backdrop_set_message(t('The cache has been cleared.'));
}

/**
 * Submit hook to clear Backdrop's theme registry (thereby triggering
 * a templates rescan).
 */
function views_ui_config_item_form_rescan($form, &$form_state) {
  backdrop_theme_rebuild();

  // The 'Theme: Information' page is about to be shown again. That page
  // analyzes the output of theme_get_registry(). However, this latter
  // function uses an internal cache (which was initialized before we
  // called backdrop_theme_rebuild()) so it won't reflect the
  // current state of our theme registry. The only way to clear that cache
  // is to re-initialize the theme system:
  unset($GLOBALS['theme']);
  backdrop_theme_initialize();

  $form_state['rerender'] = TRUE;
  $form_state['rebuild'] = TRUE;
}

/**
 * Override handler for views_ui_edit_display_form
 */
function views_ui_edit_display_form_change_theme($form, &$form_state) {
  // This is just a temporary variable.
  $form_state['view']->theme = $form_state['values']['theme'];

  views_ui_cache_set($form_state['view']);
  $form_state['rerender'] = TRUE;
  $form_state['rebuild'] = TRUE;
}

/**
 * Page callback for views tag autocomplete
 */
function views_ui_autocomplete_tag($string = '') {
  $matches = array();
  $views = views_get_all_views();
  foreach ($views as $view) {
    if (!empty($view->tag) && strpos($view->tag, $string) === 0) {
      $matches[$view->tag] = check_plain($view->tag);
      if (count($matches) >= 10) {
        break;
      }
    }
  }

  // Displayed as JSON by delivery callback backdrop_json_deliver().
  return $matches;
}

// ------------------------------------------------------------------
// Get information from the Views data

function _views_weight_sort($a, $b) {
  if ($a['weight'] != $b['weight']) {
    return $a['weight'] < $b['weight'] ? -1 : 1;
  }
  if ($a['title'] != $b['title']) {
    return $a['title'] < $b['title'] ? -1 : 1;
  }

  return 0;
}

/**
 * Fetch a list of all base tables available
 *
 * @return
 *   A keyed array of in the form of 'base_table' => 'Description'.
 */
function views_fetch_base_tables() {
  static $base_tables = array();
  if (empty($base_tables)) {
    $weights = array();
    $tables = array();
    $data = views_fetch_data();
    foreach ($data as $table => $info) {
      if (!empty($info['table']['base'])) {
        $tables[$table] = array(
          'title' => $info['table']['base']['title'],
          'description' => !empty($info['table']['base']['help']) ? $info['table']['base']['help'] : '',
          'weight' => !empty($info['table']['base']['weight']) ? $info['table']['base']['weight'] : 0,
        );
      }
    }
    uasort($tables, '_views_weight_sort');
    $base_tables = $tables;
  }

  return $base_tables;
}

function _views_sort_types($a, $b) {
  $a_group = backdrop_strtolower($a['group']);
  $b_group = backdrop_strtolower($b['group']);
  if ($a_group != $b_group) {
    return $a_group < $b_group ? -1 : 1;
  }

  $a_title = backdrop_strtolower($a['title']);
  $b_title = backdrop_strtolower($b['title']);
  if ($a_title != $b_title) {
    return $a_title < $b_title ? -1 : 1;
  }

  return 0;
}

/**
 * Placeholder function for overriding $display->display_title.
 *
 * @todo Remove this function once configuring the display title is possible.
 */
function views_ui_get_display_label($view, $display_id, $check_changed = TRUE) {
  $title = $display_id == 'default' ? t('Default') : $view->display[$display_id]->display_title;
  $title = views_ui_truncate($title, 25);

  if ($check_changed && !empty($view->changed_display[$display_id])) {
    $changed = '*';
    $title = $title . $changed;
  }

  return $title;
}

/**
 * #process callback for a button; determines if a button is the form's triggering element.
 *
 * The Form API has logic to determine the form's triggering element based on
 * the data in $_POST. However, it only checks buttons based on a single #value
 * per button. This function may be added to a button's #process callbacks to
 * extend button click detection to support multiple #values per button. If the
 * data in $_POST matches any value in the button's #values array, then the
 * button is detected as having been clicked. This can be used when the value
 * (label) of the same logical button may be different based on context (e.g.,
 * "Apply" vs. "Apply and continue").
 *
 * @see _form_builder_handle_input_element()
 * @see _form_button_was_clicked()
 */
function views_ui_form_button_was_clicked($element, &$form_state) {
  $process_input = empty($element['#disabled']) && ($form_state['programmed'] || ($form_state['process_input'] && (!isset($element['#access']) || $element['#access'])));
  if ($process_input && !isset($form_state['triggering_element']) && isset($element['#button_type']) && isset($form_state['input'][$element['#name']]) && isset($element['#values']) && in_array($form_state['input'][$element['#name']], $element['#values'], TRUE)) {
    $form_state['triggering_element'] = $element;
  }
  return $element;
}

/**
 * #process callback for a button; makes implicit form submissions trigger as this button.
 *
 * @see Backdrop.behaviors.viewsImplicitFormSubmission
 */
function views_ui_default_button($element, &$form_state, $form) {
  $setting['viewsImplicitFormSubmission'][$form['#id']]['defaultButton'] = $element['#id'];
  $element['#attached']['js'][] = array('type' => 'setting', 'data' => $setting);
  return $element;
}

/**
 * List all instances of fields on any views.
 *
 * Therefore it builds up a table of each field which is used in any view.
 *
 * @see field_ui_fields_list()
 */
function views_ui_field_list() {
  $views = views_get_all_views();

  // Fetch all fieldapi fields which are used in views
  // Therefore search in all views, displays and handler-types.
  $fields = array();
  foreach ($views as $view) {
    foreach ($view->display as $display_id => $display) {
      if ($view->set_display($display_id)) {
        foreach (views_object_types() as $type => $info) {
          foreach ($view->get_items($type, $display_id) as $item) {
            $data = views_fetch_data($item['table']);
            if (isset($data[$item['field']]) && isset($data[$item['field']][$type])
              && $data = $data[$item['field']][$type]) {
              // The final check that we have a fieldapi field now.
              if (isset($data['field_name'])) {
                $fields[$data['field_name']][$view->name] = $view->name;
              }
            }
          }
        }
      }
    }
  }

  $header = array(t('Field name'), t('Used in'));
  $rows = array();
  foreach ($fields as $field_name => $views) {

    $rows[$field_name]['data'][0] = check_plain($field_name);
    foreach ($views as $view) {
      $rows[$field_name]['data'][1][] = l($view, "admin/structure/views/view/$view");
    }
    $rows[$field_name]['data'][1] = implode(', ', $rows[$field_name]['data'][1]);
  }

  // Sort rows by field name.
  ksort($rows);
  $output = array(
    '#theme' => 'table',
    '#header' => $header,
    '#rows' => $rows,
    '#empty' => t('No fields have been used in views yet.'),
  );

  return $output;
}

/**
 * Lists all plugins and what enabled Views use them.
 */
function views_ui_plugin_list() {
  $rows = views_plugin_list();
  foreach ($rows as &$row) {
    // Link each view name to the view itself.
    foreach ($row['views'] as $row_name => $view) {
      $row['views'][$row_name] = l($view, "admin/structure/views/view/$view");
    }
    $row['views'] = implode(', ', $row['views']);
  }

  // Sort rows by field name.
  ksort($rows);
  return array(
    '#theme' => 'table',
    '#header' => array(t('Type'), t('Name'), t('Provided by'), t('Used in')),
    '#rows' => $rows,
    '#empty' => t('There are no enabled views.'),
  );
}