Club Drupal

    if (!empty($this->info['revision table']) && !empty($this->info['entity keys']['revision'])) {

      $revision_table = $this->info['revision table'];

      $data[$table]['table']['default_relationship'] = array(

        $revision_table => array(

          'table' => $revision_table,

          'field' => $this->info['entity keys']['revision'],

        ),

      );

      // Define the base group of this table. Fields that don't

      // have a group defined will go into this field by default.

      $data[$revision_table]['table']['group']  = drupal_ucfirst($this->info['label']) . ' ' . t('Revisions');

      $data[$revision_table]['table']['entity type'] = $this->type;

      // If the plural label isn't available, use the regular label.

      $label = isset($this->info['plural label']) ? $this->info['plural label'] : $this->info['label'];

      $data[$revision_table]['table']['base'] = array(

        'field' => $this->info['entity keys']['revision'],

        'access query tag' => $this->type . '_access',

        'title' => drupal_ucfirst($label) . ' ' . t('Revisions'),

        'help' => (isset($this->info['description']) ? $this->info['description'] . ' ' : '') . t('Revisions'),

      );

      $data[$revision_table]['table']['entity type'] = $this->type;

      $data[$revision_table] += $this->schema_revision_fields();

      // Add in any reverse-relationships which have been determined.

      $data += $this->relationships;

      // For other base tables, explain how we join.

      $data[$revision_table]['table']['join'] = array(

        // Directly links to base table.

        $table => array(

          'left_field' => $this->info['entity keys']['revision'],

          'field' => $this->info['entity keys']['revision'],

        ),

      );

      $data[$revision_table]['table']['default_relationship'] = array(

        $table => array(

          'table' => $table,

          'field' => $this->info['entity keys']['id'],

        ),

      );

    }

  /**

   * Try to come up with some views fields with the help of the revision schema

   * and the entity property information.

   */

  protected function schema_revision_fields() {

    $data = array();

    if (!empty($this->info['revision table'])) {

      $schema = drupal_get_schema($this->info['revision table']);

      $properties = entity_get_property_info($this->type) + array('properties' => array());

      foreach ($properties['properties'] as $name => $property_info) {

        if (isset($property_info['schema field']) && isset($schema['fields'][$property_info['schema field']])) {

          if ($views_info = $this->map_from_schema_info($name, $schema['fields'][$property_info['schema field']], $property_info)) {

            $data[$name] = $views_info;

          }

        }

      }

    }

    return $data;

  }