<?php

/**
 * @file
 * Definitions of views_handler_filter and views_handler_filter_broken.
 */

/**
 * @defgroup views_filter_handlers Views filter handlers
 * @{
 * Handlers to tell Views how to filter queries.
 *
 * Definition items:
 * - allow empty: If true, the 'IS NULL' and 'IS NOT NULL' operators become
 *   available as standard operators.
 *
 * Object flags:
 *   It's possible to set specific behavior using the following flags on the
 *   custom class:
 *   - always_multiple:
 *     Disable the possibility to force a single value.
 *   - no_operator:
 *     Disable the possibility to use operators.
 *   - always_required:
 *     Disable the possibility to allow a exposed input to be optional.
 */

/**
 * Base class for filters.
 *
 * @ingroup views_filter_handlers
 */
class views_handler_filter extends views_handler {

  /**
   * Contains the actual value of the field.
   *
   * This will be either configured in the views UI or entered in the exposed
   * filters.
   *
   * @var mixed
   */
  public $value = NULL;

  /**
   * Contains the operator which is used on the query.
   *
   * @var string
   */
  public $operator = '=';

  /**
   * Contains the information of the selected item in a gruped filter.
   *
   * @var array|null
   */
  public $group_info = NULL;

  /**
   * Disable the possibility to force a single value.
   *
   * @var bool
   */
  public $always_multiple = FALSE;

  /**
   * Disable the possibility to use operators.
   *
   * @var bool
   */
  public $no_operator = FALSE;

  /**
   * Disable the possibility to allow a exposed input to be optional.
   *
   * @var bool
   */
  public $always_required = FALSE;

  /**
   * Provide some extra help to get the operator/value easier to use.
   *
   * This likely has to be overridden by filters which are more complex
   * than simple operator/value.
   */
  public function init(&$view, &$options) {
    parent::init($view, $options);

    $this->operator = $this->options['operator'];
    $this->value = $this->options['value'];
    $this->group_info = $this->options['group_info']['default_group'];

    // Compatibility: The new UI changed several settings.
    if (!empty($options['exposed']) && !empty($options['expose']['optional']) && !isset($options['expose']['required'])) {
      $this->options['expose']['required'] = !$options['expose']['optional'];
    }
    if (!empty($options['exposed']) && !empty($options['expose']['single']) && !isset($options['expose']['multiple'])) {
      $this->options['expose']['multiple'] = !$options['expose']['single'];
    }
    if (!empty($options['exposed']) && !empty($options['expose']['operator']) && !isset($options['expose']['operator_id'])) {
      $this->options['expose']['operator_id'] = $options['expose']['operator_id'] = $options['expose']['operator'];
    }

    if ($this->multiple_exposed_input()) {
      $this->group_info = NULL;
      if (!empty($options['group_info']['default_group_multiple'])) {
        $this->group_info = array_filter($options['group_info']['default_group_multiple']);
      }

      $this->options['expose']['multiple'] = TRUE;
    }

    // If there are relationships in the view, allow empty should be true
    // so that we can do IS NULL checks on items. Not all filters respect
    // allow empty, but string and numeric do and that covers enough.
    if ($this->view->display_handler->get_option('relationships')) {
      $this->definition['allow empty'] = TRUE;
    }
  }

  /**
   * {@inheritdoc}
   */
  public function option_definition() {
    $options = parent::option_definition();

    $options['operator'] = array('default' => '=');
    $options['value'] = array('default' => '');
    $options['group'] = array('default' => '1');
    $options['exposed'] = array('default' => FALSE, 'bool' => TRUE);
    $options['expose'] = array(
      'contains' => array(
        'operator_id' => array('default' => FALSE),
        'label' => array('default' => '', 'translatable' => TRUE),
        'description' => array('default' => '', 'translatable' => TRUE),
        'use_operator' => array('default' => FALSE, 'bool' => TRUE),
        'operator_label' => array('default' => '', 'translatable' => TRUE),
        'operator' => array('default' => ''),
        'limit_operators' => array('default' => FALSE, 'bool' => TRUE),
        'available_operators' => array('default' => array()),
        'identifier' => array('default' => ''),
        'required' => array('default' => FALSE, 'bool' => TRUE),
        'remember' => array('default' => FALSE, 'bool' => TRUE),
        'multiple' => array('default' => FALSE, 'bool' => TRUE),
        'remember_roles' => array(
          'default' => array(
            DRUPAL_AUTHENTICATED_RID => DRUPAL_AUTHENTICATED_RID,
          ),
        ),
      ),
    );

    // A group is a combination of a filter, an operator and a value
    // operating like a single filter.
    // Users can choose from a select box which group they want to apply.
    // Views will filter the view according to the defined values.
    // Because it acts as a standard filter, we have to define
    // an identifier and other settings like the widget and the label.
    // This settings are saved in another array to allow users to switch
    // between a normal filter and a group of filters with a single click.
    $options['is_grouped'] = array('default' => FALSE, 'bool' => TRUE);
    $options['group_info'] = array(
      'contains' => array(
        'label' => array('default' => '', 'translatable' => TRUE),
        'description' => array('default' => '', 'translatable' => TRUE),
        'identifier' => array('default' => ''),
        'optional' => array('default' => TRUE, 'bool' => TRUE),
        'widget' => array('default' => 'select'),
        'multiple' => array('default' => FALSE, 'bool' => TRUE),
        'remember' => array('default' => 0),
        'default_group' => array('default' => 'All'),
        'default_group_multiple' => array('default' => array()),
        'group_items' => array('default' => array()),
      ),
    );

    return $options;
  }

  /**
   * Display the filter on the administrative summary.
   */
  public function admin_summary() {
    return check_plain((string) $this->operator) . ' ' . check_plain((string) $this->value);
  }

  /**
   * Determine if a filter can be exposed.
   */
  public function can_expose() {
    return TRUE;
  }

  /**
   * Determine if a filter can be converted into a group.
   *
   * Only exposed filters with operators available can be converted into groups.
   */
  public function can_build_group() {
    return $this->is_exposed() && (count($this->operator_options()) > 0);
  }

  /**
   * Returns TRUE if the exposed filter works like a grouped filter.
   */
  public function is_a_group() {
    return $this->is_exposed() && !empty($this->options['is_grouped']);
  }

  /**
   * Provide the basic form which calls through to subforms.
   *
   * If overridden, it is best to call through to the parent, or to at least
   * make sure all of the functions in this form are called.
   */
  public function options_form(&$form, &$form_state) {
    parent::options_form($form, $form_state);
    if ($this->can_expose()) {
      $this->show_expose_button($form, $form_state);
    }
    if ($this->can_build_group()) {
      $this->show_build_group_button($form, $form_state);
    }
    $form['clear_markup_start'] = array(
      '#markup' => '<div class="clearfix">',
    );
    if ($this->is_a_group()) {
      if ($this->can_build_group()) {
        $form['clear_markup_start'] = array(
          '#markup' => '<div class="clearfix">',
        );
        // Render the build group form.
        $this->show_build_group_form($form, $form_state);
        $form['clear_markup_end'] = array(
          '#markup' => '</div>',
        );
      }
    }
    else {
      // Add the subform from operator_form().
      $this->show_operator_form($form, $form_state);
      // Add the subform from value_form().
      $this->show_value_form($form, $form_state);
      $form['clear_markup_end'] = array(
        '#markup' => '</div>',
      );
      if ($this->can_expose()) {
        // Add the subform from expose_form().
        $this->show_expose_form($form, $form_state);
      }
    }
  }

  /**
   * Simple validate handler.
   */
  public function options_validate(&$form, &$form_state) {
    $this->operator_validate($form, $form_state);
    $this->value_validate($form, $form_state);
    if (!empty($this->options['exposed']) && !$this->is_a_group()) {
      $this->expose_validate($form, $form_state);
    }
    if ($this->is_a_group()) {
      $this->build_group_validate($form, $form_state);
    }
  }

  /**
   * Simple submit handler.
   */
  public function options_submit(&$form, &$form_state) {
    // Don't store these.
    unset($form_state['values']['expose_button']);
    unset($form_state['values']['group_button']);

    if (!$this->is_a_group()) {
      $this->operator_submit($form, $form_state);
      $this->value_submit($form, $form_state);
    }
    if (!empty($this->options['exposed'])) {
      $options = &$form_state['values']['options']['expose'];
      $options['available_operators'] = (!empty($options['use_operator']) && !empty($options['limit_operators'])) ? array_filter($options['available_operators']) : array();
      $this->expose_submit($form, $form_state);
    }
    if ($this->is_a_group()) {
      $this->build_group_submit($form, $form_state);
    }
  }

  /**
   * Shortcut to display the operator form.
   */
  public function show_operator_form(&$form, &$form_state) {
    $this->operator_form($form, $form_state);
    $form['operator']['#prefix'] = '<div class="views-group-box views-left-30">';
    $form['operator']['#suffix'] = '</div>';
  }

  /**
   * Options form subform for setting the operator.
   *
   * This may be overridden by child classes, and it must define
   * $form['operator'].
   *
   * @see options_form()
   */
  public function operator_form(&$form, &$form_state) {
    $options = $this->operator_options();
    if (!empty($options)) {
      $available = $this->options['expose']['available_operators'];
      if ($this->options['expose']['limit_operators'] && count($available)) {
        foreach ($options as $key => $value) {
          if (!isset($available[$key])) {
            unset($options[$key]);
          }
        }

        // Make sure we have a valid default value if the current one is
        // excluded.
        if (!isset($options[$this->operator])) {
          // Just choose the first.
          $this->operator = key($options);
        }
      }
      $form['operator'] = array(
        '#type' => count($options) < 10 ? 'radios' : 'select',
        '#title' => t('Operator'),
        '#default_value' => $this->operator,
        '#options' => $options,
      );
    }
  }

  /**
   * Provide a list of options for the default operator form.
   *
   * Should be overridden by classes that don't override operator_form.
   */
  public function operator_options() {
    return array();
  }

  /**
   * Validate the operator form.
   */
  public function operator_validate($form, &$form_state) {
  }

  /**
   * Perform any necessary changes to the form values prior to storage.
   *
   * There is no need for this function to actually store the data.
   */
  public function operator_submit($form, &$form_state) {
  }

  /**
   * Shortcut to display the value form.
   */
  public function show_value_form(&$form, &$form_state) {
    $this->value_form($form, $form_state);
    if (empty($this->no_operator)) {
      $form['value']['#prefix'] = '<div class="views-group-box views-right-70">' . (isset($form['value']['#prefix']) ? $form['value']['#prefix'] : '');
      $form['value']['#suffix'] = (isset($form['value']['#suffix']) ? $form['value']['#suffix'] : '') . '</div>';
    }
  }

  /**
   * Options form subform for setting options.
   *
   * This should be overridden by all child classes and it must define
   * $form['value'].
   *
   * @see options_form()
   */
  public function value_form(&$form, &$form_state) {
    $form['value'] = array();
  }

  /**
   * Validate the options form.
   */
  public function value_validate($form, &$form_state) {
  }

  /**
   * Perform any necessary changes to the form values prior to storage.
   *
   * There is no need for this function to actually store the data.
   */
  public function value_submit($form, &$form_state) {
  }

  /**
   * Shortcut to display the exposed options form.
   */
  public function show_build_group_form(&$form, &$form_state) {
    if (empty($this->options['is_grouped'])) {
      return;
    }

    $this->build_group_form($form, $form_state);

    // When we click the expose button, we add new gadgets to the form but they
    // have no data in $_POST so their defaults get wiped out. This prevents
    // these defaults from getting wiped out. This setting will only be TRUE
    // during a 2nd pass rerender.
    if (!empty($form_state['force_build_group_options'])) {
      foreach (element_children($form['group_info']) as $id) {
        if (isset($form['group_info'][$id]['#default_value']) && !isset($form['group_info'][$id]['#value'])) {
          $form['group_info'][$id]['#value'] = $form['group_info'][$id]['#default_value'];
        }
      }
    }
  }

  /**
   * Shortcut to display the build_group/hide button.
   */
  public function show_build_group_button(&$form, &$form_state) {
    $form['group_button'] = array(
      '#prefix' => '<div class="views-grouped clearfix">',
      '#suffix' => '</div>',
      // Should always come after the description and the relationship.
      '#weight' => -190,
    );

    $grouped_description = t('Grouped filters allow a choice between predefined operator|value pairs.');
    $form['group_button']['radios'] = array(
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('js-only')),
    );
    $form['group_button']['radios']['radios'] = array(
      '#title' => t('Filter type to expose'),
      '#description' => $grouped_description,
      '#type' => 'radios',
      '#options' => array(
        t('Single filter'),
        t('Grouped filters'),
      ),
    );

    if (empty($this->options['is_grouped'])) {
      $form['group_button']['markup'] = array(
        '#markup' => '<div class="description grouped-description">' . $grouped_description . '</div>',
      );
      $form['group_button']['button'] = array(
        '#limit_validation_errors' => array(),
        '#type' => 'submit',
        '#value' => t('Grouped filters'),
        '#submit' => array('views_ui_config_item_form_build_group'),
      );
      $form['group_button']['radios']['radios']['#default_value'] = 0;
    }
    else {
      $form['group_button']['button'] = array(
        '#limit_validation_errors' => array(),
        '#type' => 'submit',
        '#value' => t('Single filter'),
        '#submit' => array('views_ui_config_item_form_build_group'),
      );
      $form['group_button']['radios']['radios']['#default_value'] = 1;
    }
  }

  /**
   * Shortcut to display the expose/hide button.
   */
  public function show_expose_button(&$form, &$form_state) {
    $form['expose_button'] = array(
      '#prefix' => '<div class="views-expose clearfix">',
      '#suffix' => '</div>',
      // Should always come after the description and the relationship.
      '#weight' => -200,
    );

    // Add a checkbox for JS users, which will have behavior attached to it so
    // it can replace the button.
    $form['expose_button']['checkbox'] = array(
      '#theme_wrappers' => array('container'),
      '#attributes' => array('class' => array('js-only')),
    );
    $form['expose_button']['checkbox']['checkbox'] = array(
      '#title' => t('Expose this filter to visitors, to allow them to change it'),
      '#type' => 'checkbox',
    );

    // Then add the button itself.
    if (empty($this->options['exposed'])) {
      $form['expose_button']['markup'] = array(
        '#markup' => '<div class="description exposed-description">' . t('This filter is not exposed. Expose it to allow the users to change it.') . '</div>',
      );
      $form['expose_button']['button'] = array(
        '#limit_validation_errors' => array(),
        '#type' => 'submit',
        '#value' => t('Expose filter'),
        '#submit' => array('views_ui_config_item_form_expose'),
      );
      $form['expose_button']['checkbox']['checkbox']['#default_value'] = 0;
    }
    else {
      $form['expose_button']['markup'] = array(
        '#markup' => '<div class="description exposed-description">' . t('This filter is exposed. If you hide it, users will not be able to change it.') . '</div>',
      );
      $form['expose_button']['button'] = array(
        '#limit_validation_errors' => array(),
        '#type' => 'submit',
        '#value' => t('Hide filter'),
        '#submit' => array('views_ui_config_item_form_expose'),
      );
      $form['expose_button']['checkbox']['checkbox']['#default_value'] = 1;
    }
  }

  /**
   * Options form subform for exposed filter options.
   *
   * @see options_form()
   */
  public function expose_form(&$form, &$form_state) {
    $form['#theme'] = 'views_ui_expose_filter_form';
    // #flatten will move everything from $form['expose'][$key] to $form[$key]
    // prior to rendering. That's why the pre_render for it needs to run first,
    // so that when the next pre_render (the one for fieldsets) runs, it gets
    // the flattened data.
    array_unshift($form['#pre_render'], 'views_ui_pre_render_flatten_data');
    $form['expose']['#flatten'] = TRUE;

    if (empty($this->always_required)) {
      $form['expose']['required'] = array(
        '#type' => 'checkbox',
        '#title' => t('Required'),
        '#default_value' => $this->options['expose']['required'],
      );

      $operator_options = $this->operator_options();
      if (count($operator_options)) {
        $form['expose']['limit_operators'] = array(
          '#type' => 'checkbox',
          '#title' => t('Limit operators'),
          '#description' => t('When checked, the operator will be exposed to the user'),
          '#default_value' => !empty($this->options['expose']['limit_operators']),
          '#dependency' => array(
            'edit-options-expose-use-operator' => array(1),
          ),
          '#description' => t('Restrict which operators will be available to select in the exposed operator form.'),
        );

        $form['expose']['available_operators'] = array(
          '#type' => 'checkboxes',
          '#title' => t('Limit the exposed operators'),
          '#default_value' => $this->options['expose']['available_operators'],
          '#prefix' => '<div id="edit-options-expose-available-operators-wrapper"><div id="edit-options-expose-available-operators">',
          '#suffix' => '</div></div>',
          '#description' => t('Select which operators will be available to select in the exposed operator form. If none are selected, all the operators listed here will be used.'),
          '#options' => $operator_options,
          '#dependency' => array(
            'edit-options-expose-limit-operators' => array(1),
          ),
        );
      }
    }
    else {
      $form['expose']['required'] = array(
        '#type' => 'value',
        '#value' => TRUE,
      );
    }
    $form['expose']['label'] = array(
      '#type' => 'textfield',
      '#default_value' => $this->options['expose']['label'],
      '#title' => t('Label'),
      '#size' => 40,
    );

    $form['expose']['description'] = array(
      '#type' => 'textfield',
      '#default_value' => $this->options['expose']['description'],
      '#title' => t('Description'),
      '#size' => 60,
    );

    if (!empty($form['operator']['#type'])) {
      // Increase the width of the left (operator) column.
      $form['operator']['#prefix'] = '<div class="views-group-box views-left-40">';
      $form['operator']['#suffix'] = '</div>';
      $form['value']['#prefix'] = '<div class="views-group-box views-right-60">';
      $form['value']['#suffix'] = '</div>';

      $form['expose']['use_operator'] = array(
        '#type' => 'checkbox',
        '#title' => t('Expose operator'),
        '#description' => t('Allow the user to choose the operator.'),
        '#default_value' => !empty($this->options['expose']['use_operator']),
      );
      $form['expose']['operator_label'] = array(
        '#type' => 'textfield',
        '#default_value' => $this->options['expose']['operator_label'],
        '#title' => t('Operator label'),
        '#size' => 40,
        '#description' => t('This will appear before your operator select field.'),
        '#dependency' => array(
          'edit-options-expose-use-operator' => array(1),
        ),
      );
      $form['expose']['operator_id'] = array(
        '#type' => 'textfield',
        '#default_value' => $this->options['expose']['operator_id'],
        '#title' => t('Operator identifier'),
        '#size' => 40,
        '#description' => t('This will appear in the URL after the ? to identify this operator.'),
        '#dependency' => array(
          'edit-options-expose-use-operator' => array(1),
        ),
        '#fieldset' => 'more',
      );
    }
    else {
      $form['expose']['operator_id'] = array(
        '#type' => 'value',
        '#value' => '',
      );
    }

    if (empty($this->always_multiple)) {
      $form['expose']['multiple'] = array(
        '#type' => 'checkbox',
        '#title' => t('Allow multiple selections'),
        '#description' => t('Enable to allow users to select multiple items.'),
        '#default_value' => $this->options['expose']['multiple'],
      );
    }
    $form['expose']['remember'] = array(
      '#type' => 'checkbox',
      '#title' => t('Remember the last selection'),
      '#description' => t('Enable to remember the last selection made by the user.'),
      '#default_value' => $this->options['expose']['remember'],
    );

    $role_options = array_map('check_plain', user_roles());
    $form['expose']['remember_roles'] = array(
      '#type' => 'checkboxes',
      '#title' => t('User roles'),
      '#description' => t('Remember exposed selection only for the selected user role(s). If you select no roles, the exposed data will never be stored.'),
      '#default_value' => $this->options['expose']['remember_roles'],
      '#options' => $role_options,
      '#dependency' => array(
        'edit-options-expose-remember' => array(1),
      ),
    );

    $form['expose']['identifier'] = array(
      '#type' => 'textfield',
      '#default_value' => $this->options['expose']['identifier'],
      '#title' => t('Filter identifier'),
      '#size' => 40,
      '#description' => t('This will appear in the URL after the ? to identify this filter. Cannot be blank.'),
      '#fieldset' => 'more',
    );
  }

  /**
   * Validate the options form.
   */
  public function expose_validate($form, &$form_state) {
    if (empty($form_state['values']['options']['expose']['identifier'])) {
      form_error($form['expose']['identifier'], t('The identifier is required if the filter is exposed.'));
    }

    if (!empty($form_state['values']['options']['expose']['identifier'])) {
      $illegal_identifiers = array('value', 'q');
      if (in_array($form_state['values']['options']['expose']['identifier'], $illegal_identifiers)) {
        form_error($form['expose']['identifier'], t('This identifier is not allowed.'));
      }
    }

    if (!$this->view->display_handler->is_identifier_unique($form_state['id'], $form_state['values']['options']['expose']['identifier'])) {
      form_error($form['expose']['identifier'], t('This identifier is used by another handler.'));
    }

    // Filter out roles which weren't selected, so that they aren't exported.
    // This is purely cosmetic.
    if (!empty($form_state['values']['options']['expose']['remember_roles'])) {
      $form_state['values']['options']['expose']['remember_roles'] = array_filter($form_state['values']['options']['expose']['remember_roles']);
    }
  }

  /**
   * Validate the build group options form.
   */
  public function build_group_validate($form, &$form_state) {
    if (!empty($form_state['values']['options']['group_info'])) {
      if (empty($form_state['values']['options']['group_info']['identifier'])) {
        form_error($form['group_info']['identifier'], t('The identifier is required if the filter is exposed.'));
      }

      if (!empty($form_state['values']['options']['group_info']['identifier'])) {
        $illegal_identifiers = array('value', 'q');
        if (in_array($form_state['values']['options']['group_info']['identifier'], $illegal_identifiers)) {
          form_error($form['group_info']['identifier'], t('This identifier is not allowed.'));
        }
      }

      if (!$this->view->display_handler->is_identifier_unique($form_state['id'], $form_state['values']['options']['group_info']['identifier'])) {
        form_error($form['group_info']['identifier'], t('This identifier is used by another handler.'));
      }
    }

    if (!empty($form_state['values']['options']['group_info']['group_items'])) {
      foreach ($form_state['values']['options']['group_info']['group_items'] as $id => $group) {
        if (empty($group['remove'])) {
          // Check if the title is defined but value wasn't defined.
          if (!empty($group['title'])) {
            // No value is needed for 'empty' and 'not empty' operator.
            if (!in_array($group['operator'], array('empty', 'not empty'))) {
              if ((!is_array($group['value']) && trim($group['value']) == "") ||
                  (is_array($group['value']) && count(array_filter($group['value'], '_views_array_filter_zero')) == 0)) {
                form_error($form['group_info']['group_items'][$id]['value'],
                  t('The value is required if title for this item is defined.'));
              }
            }
          }

          // Check if the value is defined but title wasn't defined.
          if ((!is_array($group['value']) && trim($group['value']) != "") ||
              (is_array($group['value']) && count(array_filter($group['value'], '_views_array_filter_zero')) > 0)) {
            if (empty($group['title'])) {
              form_error($form['group_info']['group_items'][$id]['title'],
                t('The title is required if value for this item is defined.'));
            }
          }
        }
      }
    }
  }

  /**
   * Save new group items, re-enumerates and remove groups marked to delete.
   */
  public function build_group_submit($form, &$form_state) {
    $groups = array();
    uasort($form_state['values']['options']['group_info']['group_items'], 'drupal_sort_weight');

    // Filter out removed items.
    // Start from 1 to avoid problems with #default_value in the widget.
    $new_id = 1;
    $new_default = 'All';
    foreach ($form_state['values']['options']['group_info']['group_items'] as $id => $group) {
      if (empty($group['remove'])) {
        // Don't store this.
        unset($group['remove']);
        unset($group['weight']);
        $groups[$new_id] = $group;

        if ($form_state['values']['options']['group_info']['default_group'] === $id) {
          $new_default = $new_id;
        }
      }
      $new_id++;
    }
    if ($new_default != 'All') {
      $form_state['values']['options']['group_info']['default_group'] = $new_default;
    }
    $filter_default_multiple = array_filter($form_state['values']['options']['group_info']['default_group_multiple']);
    $form_state['values']['options']['group_info']['default_group_multiple'] = $filter_default_multiple;

    $form_state['values']['options']['group_info']['group_items'] = $groups;
  }

  /**
   * Provide default options for exposed filters.
   */
  public function expose_options() {
    $this->options['expose'] = array(
      'use_operator' => FALSE,
      'operator' => $this->options['id'] . '_op',
      'identifier' => $this->options['id'],
      'label' => $this->definition['title'],
      'description' => NULL,
      'remember' => FALSE,
      'multiple' => FALSE,
      'required' => FALSE,
    );
  }

  /**
   * Provide default options for exposed filters.
   */
  public function build_group_options() {
    $this->options['group_info'] = array(
      'label' => $this->definition['title'],
      'description' => NULL,
      'identifier' => $this->options['id'],
      'optional' => TRUE,
      'widget' => 'select',
      'multiple' => FALSE,
      'remember' => FALSE,
      'default_group' => 'All',
      'default_group_multiple' => array(),
      'group_items' => array(),
    );
  }

  /**
   * Build a form with a group of operator | values to apply as a single filter.
   */
  public function group_form(&$form, &$form_state) {
    if (!empty($this->options['group_info']['optional']) && !$this->multiple_exposed_input()) {
      $old_any = $this->options['group_info']['widget'] == 'select' ? '<Any>' : '&lt;Any&gt;';
      $any_label = variable_get('views_exposed_filter_any_label', 'new_any') == 'old_any' ? $old_any : t('- Any -');
      $groups = array('All' => $any_label);
    }
    foreach ($this->options['group_info']['group_items'] as $id => $group) {
      if (!empty($group['title'])) {
        $groups[$id] = $id != 'All' ? t($group['title']) : $group['title'];
      }
    }

    if (count($groups)) {
      $value = $this->options['group_info']['identifier'];

      $form[$value] = array(
        '#type' => $this->options['group_info']['widget'],
        '#default_value' => $this->group_info,
        '#options' => $groups,
      );
      if (!empty($this->options['group_info']['multiple'])) {
        if (count($groups) < 5) {
          $form[$value]['#type'] = 'checkboxes';
        }
        else {
          $form[$value]['#type'] = 'select';
          $form[$value]['#size'] = 5;
          $form[$value]['#multiple'] = TRUE;
        }
        unset($form[$value]['#default_value']);
        if (empty($form_state['input'][$value])) {
          $form_state['input'][$value] = $this->group_info;
        }
      }

      $this->options['expose']['label'] = '';
    }
  }

  /**
   * Render our chunk of the exposed filter form when selecting.
   *
   * You can override this if it doesn't do what you expect.
   */
  public function exposed_form(&$form, &$form_state) {
    if (empty($this->options['exposed'])) {
      return;
    }

    // Build the exposed form, when its based on an operator.
    if (!empty($this->options['expose']['use_operator']) && !empty($this->options['expose']['operator_id'])) {
      $operator = $this->options['expose']['operator_id'];
      $this->operator_form($form, $form_state);
      $form[$operator] = $form['operator'];
      $form[$operator]['#title'] = $this->options['expose']['operator_label'];
      $form[$operator]['#title_display'] = 'invisible';

      $this->exposed_translate($form[$operator], 'operator');

      unset($form['operator']);
    }

    // Build the form and set the value based on the identifier.
    if (!empty($this->options['expose']['identifier'])) {
      $value = $this->options['expose']['identifier'];
      if ($this->operator == 'empty' || $this->operator == 'not empty') {
        $boolean = new views_handler_filter_boolean_operator();
        $boolean->value = $this->value = 'All';
        $boolean->value_value = $this->value_value = '';
        $boolean->value_options = $this->value_options = array(
          1 => t('Yes'),
          0 => t('No'),
        );
        $boolean->value_form($form, $form_state);
      }
      else {
        $this->value_form($form, $form_state);
      }
      $form[$value] = $form['value'];

      if (isset($form[$value]['#title']) && !empty($form[$value]['#type']) && $form[$value]['#type'] != 'checkbox') {
        unset($form[$value]['#title']);
      }

      $this->exposed_translate($form[$value], 'value');

      if (!empty($form['#type']) && ($form['#type'] == 'checkboxes' || ($form['#type'] == 'select' && !empty($form['#multiple'])))) {
        unset($form[$value]['#default_value']);
      }

      if (!empty($form['#type']) && $form['#type'] == 'select' && empty($form['#multiple'])) {
        $form[$value]['#default_value'] = 'All';
      }

      if ($value != 'value') {
        unset($form['value']);
      }
    }
  }

  /**
   * Build the form to let users create the group of exposed filters.
   *
   * This form is displayed when users click on button 'Build group'
   */
  public function build_group_form(&$form, &$form_state) {
    if (empty($this->options['exposed']) || empty($this->options['is_grouped'])) {
      return;
    }
    $form['#theme'] = 'views_ui_build_group_filter_form';

    // #flatten will move everything from $form['group_info'][$key] to
    // $form[$key] prior to rendering. That's why the pre_render for it needs
    // to run first, so that when the next pre_render (the one for fieldsets)
    // runs, it gets the flattened data.
    array_unshift($form['#pre_render'], 'views_ui_pre_render_flatten_data');
    $form['group_info']['#flatten'] = TRUE;

    if (!empty($this->options['group_info']['identifier'])) {
      $identifier = $this->options['group_info']['identifier'];
    }
    else {
      $identifier = 'group_' . $this->options['expose']['identifier'];
    }
    $form['group_info']['identifier'] = array(
      '#type' => 'textfield',
      '#default_value' => $identifier,
      '#title' => t('Filter identifier'),
      '#size' => 40,
      '#description' => t('This will appear in the URL after the ? to identify this filter. Cannot be blank.'),
      '#fieldset' => 'more',
    );
    $form['group_info']['label'] = array(
      '#type' => 'textfield',
      '#default_value' => $this->options['group_info']['label'],
      '#title' => t('Label'),
      '#size' => 40,
    );

    $form['group_info']['optional'] = array(
      '#type' => 'checkbox',
      '#title' => t('Optional'),
      '#description' => t('This exposed filter is optional and will have added options to allow it not to be set.'),
      '#default_value' => $this->options['group_info']['optional'],
    );
    $form['group_info']['multiple'] = array(
      '#type' => 'checkbox',
      '#title' => t('Allow multiple selections'),
      '#description' => t('Enable to allow users to select multiple items.'),
      '#default_value' => $this->options['group_info']['multiple'],
    );
    $form['group_info']['widget'] = array(
      '#type' => 'radios',
      '#default_value' => $this->options['group_info']['widget'],
      '#title' => t('Widget type'),
      '#options' => array(
        'radios' => t('Radios'),
        'select' => t('Select'),
      ),
      '#description' => t('Select which kind of widget will be used to render the group of filters'),
    );
    $form['group_info']['remember'] = array(
      '#type' => 'checkbox',
      '#title' => t('Remember'),
      '#description' => t('Remember the last setting the user gave this filter.'),
      '#default_value' => $this->options['group_info']['remember'],
    );

    if (!empty($this->options['group_info']['identifier'])) {
      $identifier = $this->options['group_info']['identifier'];
    }
    else {
      $identifier = 'group_' . $this->options['expose']['identifier'];
    }
    $form['group_info']['identifier'] = array(
      '#type' => 'textfield',
      '#default_value' => $identifier,
      '#title' => t('Filter identifier'),
      '#size' => 40,
      '#description' => t('This will appear in the URL after the ? to identify this filter. Cannot be blank.'),
      '#fieldset' => 'more',
    );
    $form['group_info']['label'] = array(
      '#type' => 'textfield',
      '#default_value' => $this->options['group_info']['label'],
      '#title' => t('Label'),
      '#size' => 40,
    );
    $form['group_info']['description'] = array(
      '#type' => 'textfield',
      '#default_value' => $this->options['group_info']['description'],
      '#title' => t('Description'),
      '#size' => 60,
    );
    $form['group_info']['optional'] = array(
      '#type' => 'checkbox',
      '#title' => t('Optional'),
      '#description' => t('This exposed filter is optional and will have added options to allow it not to be set.'),
      '#default_value' => $this->options['group_info']['optional'],
    );
    $form['group_info']['widget'] = array(
      '#type' => 'radios',
      '#default_value' => $this->options['group_info']['widget'],
      '#title' => t('Widget type'),
      '#options' => array(
        'radios' => t('Radios'),
        'select' => t('Select'),
      ),
      '#description' => t('Select which kind of widget will be used to render the group of filters'),
    );
    $form['group_info']['remember'] = array(
      '#type' => 'checkbox',
      '#title' => t('Remember'),
      '#description' => t('Remember the last setting the user gave this filter.'),
      '#default_value' => $this->options['group_info']['remember'],
    );

    // The string '- Any -' will not be rendered.
    // @see theme_views_ui_build_group_filter_form()
    $groups = array('All' => '- Any -');

    // Provide 3 options to start when we are in a new group.
    if (count($this->options['group_info']['group_items']) == 0) {
      $this->options['group_info']['group_items'] = array_fill(1, 3, array());
    }

    // After the general settings, comes a table with all the existent groups.
    $default_weight = 0;
    foreach ($this->options['group_info']['group_items'] as $item_id => $item) {
      if (!empty($form_state['values']['options']['group_info']['group_items'][$item_id]['remove'])) {
        continue;
      }

      // Each rows contains three widgets:
      // a) The title, where users define how they identify a pair of operator
      //    | value.
      // b) The operator.
      // c) The value (or values) to use in the filter with the selected
      //    operator.
      // In each row, we have to display the operator form and the value from
      // $row acts as a fake form to render each widget in a row.
      $row = array();
      $groups[$item_id] = '';
      $this->operator_form($row, $form_state);
      // Force the operator form to be a select box. Some handlers uses radios
      // and they occupy a lot of space in a table row.
      $row['operator']['#type'] = 'select';
      $row['operator']['#title'] = '';
      $this->value_form($row, $form_state);

      // Fix the dependencies to update value forms when operators changes.
      // This is needed because forms are inside a new form and their IDs
      // changes. Dependencies are used when operator changes from to
      // 'Between', 'Not Between', etc, and two or more widgets are displayed.
      $without_children = TRUE;
      foreach (element_children($row['value']) as $children) {
        if (isset($row['value'][$children]['#dependency']['edit-options-operator'])) {
          $row['value'][$children]['#dependency']["edit-options-group-info-group-items-$item_id-operator"] = $row['value'][$children]['#dependency']['edit-options-operator'];
          unset($row['value'][$children]['#dependency']['edit-options-operator']);
          $row['value'][$children]['#title'] = '';

          if (!empty($this->options['group_info']['group_items'][$item_id]['value'][$children])) {
            $row['value'][$children]['#default_value'] = $this->options['group_info']['group_items'][$item_id]['value'][$children];
          }
        }
        $without_children = FALSE;
      }

      if ($without_children) {
        if (!empty($this->options['group_info']['group_items'][$item_id]['value'])) {
          $row['value']['#default_value'] = $this->options['group_info']['group_items'][$item_id]['value'];
        }
      }

      if (!empty($this->options['group_info']['group_items'][$item_id]['operator'])) {
        $row['operator']['#default_value'] = $this->options['group_info']['group_items'][$item_id]['operator'];
      }

      $default_title = '';
      if (!empty($this->options['group_info']['group_items'][$item_id]['title'])) {
        $default_title = $this->options['group_info']['group_items'][$item_id]['title'];
      }

      // Per item group, we have a title that identifies it.
      $form['group_info']['group_items'][$item_id] = array(
        'title' => array(
          '#type' => 'textfield',
          '#size' => 20,
          '#default_value' => $default_title,
        ),
        'operator' => $row['operator'],
        'value' => $row['value'],
        'remove' => array(
          '#type' => 'checkbox',
          '#id' => 'views-removed-' . $item_id,
          '#attributes' => array('class' => array('views-remove-checkbox')),
          '#default_value' => 0,
        ),
        'weight' => array(
          '#type' => 'weight',
          '#delta' => count($this->options['group_info']['group_items']),
          '#default_value' => $default_weight++,
          '#attributes' => array('class' => array('weight')),
        ),
      );
    }

    // From all groups, let chose which is the default.
    $form['group_info']['default_group'] = array(
      '#type' => 'radios',
      '#options' => $groups,
      '#default_value' => $this->options['group_info']['default_group'],
      '#required' => TRUE,
      '#attributes' => array(
        'class' => array('default-radios'),
      ),
    );

    // From all groups, let chose which is the default.
    $form['group_info']['default_group_multiple'] = array(
      '#type' => 'checkboxes',
      '#options' => $groups,
      '#default_value' => $this->options['group_info']['default_group_multiple'],
      '#attributes' => array(
        'class' => array('default-checkboxes'),
      ),
    );

    $form['group_info']['add_group'] = array(
      '#prefix' => '<div class="views-build-group clear-block">',
      '#suffix' => '</div>',
      '#type' => 'submit',
      '#value' => t('Add another item'),
      '#submit' => array('views_ui_config_item_form_add_group'),
    );

    $js = array();
    $js['tableDrag']['views-filter-groups']['weight'][0] = array(
      'target' => 'weight',
      'source' => NULL,
      'relationship' => 'sibling',
      'action' => 'order',
      'hidden' => TRUE,
      'limit' => 0,
    );
    if (!empty($form_state['js settings']) && is_array($js)) {
      $form_state['js settings'] = array_merge($form_state['js settings'], $js);
    }
    else {
      $form_state['js settings'] = $js;
    }
  }

  /**
   * Make some translations to a form item to make it more suitable to exposing.
   */
  public function exposed_translate(&$form, $type) {
    if (!isset($form['#type'])) {
      return;
    }

    if ($form['#type'] == 'radios') {
      $form['#type'] = 'select';
    }
    // Checkboxes don't work so well in exposed forms due to GET conversions.
    if ($form['#type'] == 'checkboxes') {
      if (empty($form['#no_convert']) || empty($this->options['expose']['multiple'])) {
        $form['#type'] = 'select';
      }
      if (!empty($this->options['expose']['multiple'])) {
        $form['#multiple'] = TRUE;
      }
    }
    if (empty($this->options['expose']['multiple']) && isset($form['#multiple'])) {
      unset($form['#multiple']);
      $form['#size'] = NULL;
    }

    // Cleanup in case the translated element's (radios or checkboxes) display
    // value contains html.
    if ($form['#type'] == 'select') {
      $this->prepare_filter_select_options($form['#options']);
    }

    if ($type == 'value' && empty($this->always_required) && empty($this->options['expose']['required']) && $form['#type'] == 'select' && empty($form['#multiple'])) {
      $any_label = variable_get('views_exposed_filter_any_label', 'new_any') == 'old_any' ? t('<Any>') : t('- Any -');
      $form['#options'] = array('All' => $any_label) + $form['#options'];
      if (empty($form['#default_value'])) {
        $form['#default_value'] = 'All';
      }
    }

    if (!empty($this->options['expose']['required'])) {
      $form['#required'] = TRUE;
    }
  }

  /**
   * Sanitizes the HTML select element's options.
   *
   * The function is recursive to support optgroups.
   */
  public function prepare_filter_select_options(&$options) {
    foreach ($options as $value => $label) {
      // Recurse for optgroups.
      if (is_array($label)) {
        $this->prepare_filter_select_options($options[$value]);
      }
      // FAPI has some special value to allow hierarchy.
      // @see _form_options_flatten()
      elseif (is_object($label)) {
        $this->prepare_filter_select_options($options[$value]->option);
      }
      else {
        $options[$value] = strip_tags(decode_entities($label));
      }
    }
  }

  /**
   * Tell the renderer about our exposed form.
   *
   * This only needs to be overridden for particularly complex forms. And maybe
   * not even then.
   *
   * @return array|null
   *   For standard exposed filters. An array with the following keys:
   *   - operator: The $form key of the operator. Set to NULL if no operator.
   *   - value: The $form key of the value. Set to NULL if no value.
   *   - label: The label to use for this piece.
   *   For grouped exposed filters. An array with the following keys:
   *   - value: The $form key of the value. Set to NULL if no value.
   *   - label: The label to use for this piece.
   */
  public function exposed_info() {
    if (empty($this->options['exposed'])) {
      return;
    }

    if ($this->is_a_group()) {
      return array(
        'value' => $this->options['group_info']['identifier'],
        'label' => $this->options['group_info']['label'],
        'description' => $this->options['group_info']['description'],
      );
    }

    return array(
      'operator' => $this->options['expose']['operator_id'],
      'value' => $this->options['expose']['identifier'],
      'label' => $this->options['expose']['label'],
      'description' => $this->options['expose']['description'],
    );
  }

  /**
   * Transform the input from a grouped filter into a standard filter.
   *
   * When a filter is a group, find the set of operator and values that the
   * choosen item represents, and inform views that a normal filter was
   * submitted by telling the operator and the value selected.
   *
   * The param $selected_group_id is only passed when the filter uses the
   * checkboxes widget, and this function will be called for each item choosen
   * in the checkboxes.
   */
  public function convert_exposed_input(&$input, $selected_group_id = NULL) {
    if ($this->is_a_group()) {
      // If it is already defined the selected group, use it. Only valid when
      // the filter uses checkboxes for widget.
      if (!empty($selected_group_id)) {
        $selected_group = $selected_group_id;
      }
      else {
        $selected_group = $input[$this->options['group_info']['identifier']];
      }
      if ($selected_group == 'All' && !empty($this->options['group_info']['optional'])) {
        return NULL;
      }
      if ($selected_group != 'All' && empty($this->options['group_info']['group_items'][$selected_group])) {
        return FALSE;
      }
      if (isset($selected_group) && isset($this->options['group_info']['group_items'][$selected_group])) {
        $input[$this->options['expose']['operator']] = $this->options['group_info']['group_items'][$selected_group]['operator'];

        // Value can be optional, For example for 'empty' and 'not empty'
        // filters.
        if (!empty($this->options['group_info']['group_items'][$selected_group]['value'])) {
          $input[$this->options['expose']['identifier']] = $this->options['group_info']['group_items'][$selected_group]['value'];
        }
        $this->options['expose']['use_operator'] = TRUE;

        $this->group_info = $input[$this->options['group_info']['identifier']];
        return TRUE;
      }
      else {
        return FALSE;
      }
    }
  }

  /**
   * Options available for a grouped filter which uses checkboxes.
   *
   * Note: has to be applied several times, one per item selected.
   *
   * @return array
   *   The options available for a grouped filter.
   */
  public function group_multiple_exposed_input(&$input) {
    if (!empty($input[$this->options['group_info']['identifier']])) {
      return array_filter($input[$this->options['group_info']['identifier']]);
    }
    return array();
  }

  /**
   * Indicate whether users can select multiple group items.
   *
   * @return bool
   *   TRUE if users can select multiple groups items of a grouped exposed
   *   filter.
   */
  public function multiple_exposed_input() {
    return $this->is_a_group() && !empty($this->options['group_info']['multiple']);
  }

  /**
   * If set to remember exposed input in the session, store it there.
   *
   * This function is similar to store_exposed_input but modified to work
   * properly when the filter is a group.
   */
  public function store_group_input($input, $status) {
    if (!$this->is_a_group() || empty($this->options['group_info']['identifier'])) {
      return TRUE;
    }

    if (empty($this->options['group_info']['remember'])) {
      return;
    }

    // Figure out which display id is responsible for the filters, so we know
    // where to look for session stored values.
    $display_id = ($this->view->display_handler->is_defaulted('filters')) ? 'default' : $this->view->current_display;

    // False means that we got a setting that means to recuse ourselves, so we
    // should erase whatever happened to be there.
    if ($status === FALSE && isset($_SESSION['views'][$this->view->name][$display_id])) {
      $session = &$_SESSION['views'][$this->view->name][$display_id];

      if (isset($session[$this->options['group_info']['identifier']])) {
        unset($session[$this->options['group_info']['identifier']]);
      }
    }

    if ($status !== FALSE) {
      if (!isset($_SESSION['views'][$this->view->name][$display_id])) {
        $_SESSION['views'][$this->view->name][$display_id] = array();
      }

      $session = &$_SESSION['views'][$this->view->name][$display_id];

      $session[$this->options['group_info']['identifier']] = $input[$this->options['group_info']['identifier']];
    }
  }

  /**
   * Check to see if input from the exposed filters should change the behavior.
   */
  public function accept_exposed_input($input) {
    if (empty($this->options['exposed'])) {
      return TRUE;
    }

    if (!empty($this->options['expose']['use_operator']) && !empty($this->options['expose']['operator_id']) && isset($input[$this->options['expose']['operator_id']])) {
      $this->operator = $input[$this->options['expose']['operator_id']];
    }

    if (!empty($this->options['expose']['identifier'])) {
      if (isset($input[$this->options['expose']['identifier']])) {
        $value = $input[$this->options['expose']['identifier']];
      }
      else {
        return FALSE;
      }

      // Various ways to check for the absence of non-required input.
      if (empty($this->options['expose']['required'])) {
        if ($this->operator == 'empty' || $this->operator == 'not empty') {
          if (is_array($value) && array_key_exists('value', $value)) {
            $value = $value['value'];
          }
          $this->operator = ($this->operator == 'empty' && empty($value)) || ($this->operator == 'not empty' && !empty($value)) ? 'not empty' : 'empty';
        }

        if ($value == 'All' || $value === array()) {
          return FALSE;
        }

        if (!empty($this->always_multiple) && $value === '') {
          return FALSE;
        }
      }

      if (isset($value)) {
        $this->value = $value;
        if (empty($this->always_multiple) && empty($this->options['expose']['multiple'])) {
          $this->value = array($value);
        }
      }
      else {
        return FALSE;
      }
    }

    return TRUE;
  }

  /**
   * Store the exposed input for processing later.
   */
  public function store_exposed_input($input, $status) {
    if (empty($this->options['exposed']) || empty($this->options['expose']['identifier'])) {
      return TRUE;
    }

    if (empty($this->options['expose']['remember'])) {
      return;
    }

    // Check if we store exposed value for current user.
    global $user;
    $allowed_rids = empty($this->options['expose']['remember_roles']) ? array() : array_filter($this->options['expose']['remember_roles']);
    $intersect_rids = array_intersect_key($allowed_rids, $user->roles);
    if (empty($intersect_rids)) {
      return;
    }

    // Figure out which display id is responsible for the filters, so we know
    // where to look for session stored values.
    $display_id = ($this->view->display_handler->is_defaulted('filters')) ? 'default' : $this->view->current_display;

    // Shortcut test.
    $operator = !empty($this->options['expose']['use_operator']) && !empty($this->options['expose']['operator_id']);

    // False means that we got a setting that means to recuse ourselves, so we
    // should erase whatever happened to be there.
    if (!$status && isset($_SESSION['views'][$this->view->name][$display_id])) {
      $session = &$_SESSION['views'][$this->view->name][$display_id];
      if ($operator && isset($session[$this->options['expose']['operator_id']])) {
        unset($session[$this->options['expose']['operator_id']]);
      }

      if (isset($session[$this->options['expose']['identifier']])) {
        unset($session[$this->options['expose']['identifier']]);
      }
    }

    if ($status) {
      if (!isset($_SESSION['views'][$this->view->name][$display_id])) {
        $_SESSION['views'][$this->view->name][$display_id] = array();
      }

      $session = &$_SESSION['views'][$this->view->name][$display_id];

      if ($operator && isset($input[$this->options['expose']['operator_id']])) {
        $session[$this->options['expose']['operator_id']] = $input[$this->options['expose']['operator_id']];
      }

      if (isset($input[$this->options['expose']['identifier']])) {
        $session[$this->options['expose']['identifier']] = $input[$this->options['expose']['identifier']];
      }
    }
  }

  /**
   * Add this filter to the query.
   *
   * Due to the nature of fapi, the value and the operator have an unintended
   * level of indirection. You will find them in $this->operator and
   * $this->value respectively.
   */
  public function query() {
    $this->ensure_my_table();
    $this->query->add_where($this->options['group'], "$this->table_alias.$this->real_field", $this->value, $this->operator);
  }

  /**
   * Can this filter be used in OR groups?
   *
   * Some filters have complicated where clauses that cannot be easily used with
   * OR groups. Some filters must also use HAVING which also makes them not
   * groupable. These filters will end up in a special group if OR grouping is
   * in use.
   *
   * @return bool
   *   Whether the filter can be used in OR groups.
   */
  public function can_group() {
    return TRUE;
  }

}


/**
 * A special handler to take the place of missing or broken handlers.
 *
 * @ingroup views_filter_handlers
 */
class views_handler_filter_broken extends views_handler_filter {

  /**
   * {@inheritdoc}
   */
  public function ui_name($short = FALSE) {
    return t('Broken/missing handler');
  }

  /**
   * {@inheritdoc}
   */
  public function ensure_my_table() {
    // No table to ensure!
  }

  /**
   * {@inheritdoc}
   */
  public function query($group_by = FALSE) {
    // No query to run.
  }

  /**
   * {@inheritdoc}
   */
  public function options_form(&$form, &$form_state) {
    $form['markup'] = array(
      '#markup' => '<div class="form-item description">' . t('The handler for this item is broken or missing and cannot be used. If a module provided the handler and was disabled, re-enabling the module may restore it. Otherwise, you should probably delete this item.') . '</div>',
    );
  }

  /**
   * {@inheritdoc}
   */
  public function broken() {
    return TRUE;
  }

}

/**
 * Filter by no empty values, though allow to use "0".
 *
 * @param string $var
 *   The string to check.
 *
 * @return bool
 *   Indicates if the argument is an empty string.
 */
function _views_array_filter_zero($var) {
  return trim($var) != '';
}

/**
 * @}
 */
