class ViewExecutable in Zircon Profile 8

Represents a view as a whole.

An object to contain all of the data to generate a view, plus the member functions to build the view query, execute the query and render the output.

Hierarchy

• class \Drupal\views\ViewExecutable implements \Drupal\views\Serializable uses DependencySerializationTrait

95 files declare their use of ViewExecutable

AddHandler.php in core/modules/views_ui/src/Form/Ajax/AddHandler.php

Contains \Drupal\views_ui\Form\Ajax\AddHandler.

AreaPluginBase.php in core/modules/views/src/Plugin/views/area/AreaPluginBase.php

Contains \Drupal\views\Plugin\views\area\AreaPluginBase.

ArgumentPluginBase.php in core/modules/views/src/Plugin/views/argument/ArgumentPluginBase.php

Contains \Drupal\views\Plugin\views\argument\ArgumentPluginBase.

AssertViewsCacheTagsTrait.php in core/modules/views/src/Tests/AssertViewsCacheTagsTrait.php

Contains \Drupal\views\Tests\AssertViewsCacheTagsTrait.

Attachment.php in core/modules/views/src/Plugin/views/display/Attachment.php

Contains \Drupal\views\Plugin\views\display\Attachment.

... See full list

File

core/modules/views/src/ViewExecutable.php, line 27

Contains \Drupal\views\ViewExecutable.

Namespace

Drupal\views

class ViewExecutable implements \Serializable {
  use DependencySerializationTrait;

  /**
   * The config entity in which the view is stored.
   *
   * @var \Drupal\views\Entity\View
   */
  public $storage;

  /**
   * Whether or not the view has been built.
   *
   * @todo Group with other static properties.
   *
   * @var bool
   */
  public $built = FALSE;

  /**
   * Whether the view has been executed/query has been run.
   *
   * @todo Group with other static properties.
   *
   * @var bool
   */
  public $executed = FALSE;

  /**
   * Any arguments that have been passed into the view.
   *
   * @var array
   */
  public $args = array();

  /**
   * An array of build info.
   *
   * @var array
   */
  public $build_info = array();

  /**
   * Whether this view uses AJAX.
   *
   * @var bool
   */
  protected $ajaxEnabled = FALSE;

  /**
   * Where the results of a query will go.
   *
   * The array must use a numeric index starting at 0.
   *
   * @var \Drupal\views\ResultRow[]
   */
  public $result = array();

  // May be used to override the current pager info.

  /**
   * The current page. If the view uses pagination.
   *
   * @var int
   */
  protected $current_page = NULL;

  /**
   * The number of items per page.
   *
   * @var int
   */
  protected $items_per_page = NULL;

  /**
   * The pager offset.
   *
   * @var int
   */
  protected $offset = NULL;

  /**
   * The total number of rows returned from the query.
   *
   * @var int
   */
  public $total_rows = NULL;

  /**
   * Attachments to place before the view.
   *
   * @var array()
   */
  public $attachment_before = array();

  /**
   * Attachments to place after the view.
   *
   * @var array
   */
  public $attachment_after = array();

  /**
   * Feed icons attached to the view.
   *
   * @var array
   */
  public $feedIcons = array();

  // Exposed widget input

  /**
   * All the form data from $form_state->getValues().
   *
   * @var array
   */
  public $exposed_data = array();

  /**
   * An array of input values from exposed forms.
   *
   * @var array
   */
  protected $exposed_input = array();

  /**
   * Exposed widget input directly from the $form_state->getValues().
   *
   * @var array
   */
  public $exposed_raw_input = array();

  /**
   * Used to store views that were previously running if we recurse.
   *
   * @var \Drupal\views\ViewExecutable[]
   */
  public $old_view = array();

  /**
   * To avoid recursion in views embedded into areas.
   *
   * @var \Drupal\views\ViewExecutable[]
   */
  public $parent_views = array();

  /**
   * Whether this view is an attachment to another view.
   *
   * @var bool
   */
  public $is_attachment = NULL;

  /**
   * Identifier of the current display.
   *
   * @var string
   */
  public $current_display;

  /**
   * Where the $query object will reside.
   *
   * @var \Drupal\views\Plugin\views\query\QueryPluginBase
   */
  public $query = NULL;

  /**
   * The used pager plugin used by the current executed view.
   *
   * @var \Drupal\views\Plugin\views\pager\PagerPluginBase
   */
  public $pager = NULL;

  /**
   * The current used display plugin.
   *
   * @var \Drupal\views\Plugin\views\display\DisplayPluginBase
   */
  public $display_handler;

  /**
   * The list of used displays of the view.
   *
   * An array containing Drupal\views\Plugin\views\display\DisplayPluginBase
   * objects.
   *
   * @var \Drupal\views\DisplayPluginCollection
   */
  public $displayHandlers;

  /**
   * The current used style plugin.
   *
   * @var \Drupal\views\Plugin\views\style\StylePluginBase
   */
  public $style_plugin;

  /**
   * The current used row plugin, if the style plugin supports row plugins.
   *
   * @var \Drupal\views\Plugin\views\row\RowPluginBase
   */
  public $rowPlugin;

  /**
   * Stores the current active row while rendering.
   *
   * @var int
   */
  public $row_index;

  /**
   * Allow to override the url of the current view.
   *
   * @var \Drupal\Core\Url
   */
  public $override_url;

  /**
   * Allow to override the path used for generated urls.
   *
   * @var string
   */
  public $override_path = NULL;

  /**
   * Allow to override the used database which is used for this query.
   *
   * @var bool
   */
  public $base_database = NULL;

  // Handlers which are active on this view.

  /**
   * Stores the field handlers which are initialized on this view.
   *
   * @var \Drupal\views\Plugin\views\field\FieldPluginBase[]
   */
  public $field;

  /**
   * Stores the argument handlers which are initialized on this view.
   *
   * @var \Drupal\views\Plugin\views\argument\ArgumentPluginBase[]
   */
  public $argument;

  /**
   * Stores the sort handlers which are initialized on this view.
   *
   * @var \Drupal\views\Plugin\views\sort\SortPluginBase[]
   */
  public $sort;

  /**
   * Stores the filter handlers which are initialized on this view.
   *
   * @var \Drupal\views\Plugin\views\filter\FilterPluginBase[]
   */
  public $filter;

  /**
   * Stores the relationship handlers which are initialized on this view.
   *
   * @var \Drupal\views\Plugin\views\relationship\RelationshipPluginBase[]
   */
  public $relationship;

  /**
   * Stores the area handlers for the header which are initialized on this view.
   *
   * @var \Drupal\views\Plugin\views\area\AreaPluginBase[]
   */
  public $header;

  /**
   * Stores the area handlers for the footer which are initialized on this view.
   *
   * @var \Drupal\views\Plugin\views\area\AreaPluginBase[]
   */
  public $footer;

  /**
   * Stores the area handlers for the empty text which are initialized on this view.
   *
   * An array containing Drupal\views\Plugin\views\area\AreaPluginBase objects.
   *
   * @var \Drupal\views\Plugin\views\area\AreaPluginBase[]
   */
  public $empty;

  /**
   * Stores the current response object.
   *
   * @var \Symfony\Component\HttpFoundation\Response
   */
  protected $response = NULL;

  /**
   * Stores the current request object.
   *
   * @var \Symfony\Component\HttpFoundation\Request
   */
  protected $request;

  /**
   * Does this view already have loaded it's handlers.
   *
   * @todo Group with other static properties.
   *
   * @var bool
   */
  public $inited;

  /**
   * The rendered output of the exposed form.
   *
   * @var string
   */
  public $exposed_widgets;

  /**
   * If this view has been previewed.
   *
   * @var bool
   */
  public $preview;

  /**
   * Force the query to calculate the total number of results.
   *
   * @todo Move to the query.
   *
   * @var bool
   */
  public $get_total_rows;

  /**
   * Indicates if the sorts have been built.
   *
   * @todo Group with other static properties.
   *
   * @var bool
   */
  public $build_sort;

  /**
   * Stores the many-to-one tables for performance.
   *
   * @var array
   */
  public $many_to_one_tables;

  /**
   * A unique identifier which allows to update multiple views output via js.
   *
   * @var string
   */
  public $dom_id;

  /**
   * A render array container to store render related information.
   *
   * For example you can alter the array and attach some asset library or JS
   * settings via the #attached key. This is the required way to add custom
   * CSS or JS.
   *
   * @var array
   *
   * @see \Drupal\Core\Render\AttachmentsResponseProcessorInterface::processAttachments()
   */
  public $element = [
    '#attached' => [
      'library' => [
        'views/views.module',
      ],
      'drupalSettings' => [],
    ],
    '#cache' => [],
  ];

  /**
   * The current user.
   *
   * @var \Drupal\Core\Session\AccountInterface
   */
  protected $user;

  /**
   * Should the admin links be shown on the rendered view.
   *
   * @var bool
   */
  protected $showAdminLinks;

  /**
   * The views data.
   *
   * @var \Drupal\views\ViewsData
   */
  protected $viewsData;

  /**
   * The route provider.
   *
   * @var \Drupal\Core\Routing\RouteProviderInterface
   */
  protected $routeProvider;

  /**
   * Constructs a new ViewExecutable object.
   *
   * @param \Drupal\views\ViewEntityInterface $storage
   *   The view config entity the actual information is stored on.
   * @param \Drupal\Core\Session\AccountInterface $user
   *   The current user.
   * @param \Drupal\views\ViewsData $views_data
   *   The views data.
   * @param \Drupal\Core\Routing\RouteProviderInterface $route_provider
   *   The route provider.
   */
  public function __construct(ViewEntityInterface $storage, AccountInterface $user, ViewsData $views_data, RouteProviderInterface $route_provider) {

    // Reference the storage and the executable to each other.
    $this->storage = $storage;
    $this->storage
      ->set('executable', $this);
    $this->user = $user;
    $this->viewsData = $views_data;
    $this->routeProvider = $route_provider;
  }

  /**
   * Returns the identifier.
   *
   * @return string|null
   *   The entity identifier, or NULL if the object does not yet have an
   *   identifier.
   */
  public function id() {
    return $this->storage
      ->id();
  }

  /**
   * Saves the view.
   */
  public function save() {
    $this->storage
      ->save();
  }

  /**
   * Set the arguments that come to this view. Usually from the URL
   * but possibly from elsewhere.
   */
  public function setArguments(array $args) {

    // The array keys of the arguments will be incorrect if set by
    // views_embed_view() or \Drupal\views\ViewExecutable:preview().
    $this->args = array_values($args);
  }

  /**
   * Expands the list of used cache contexts for the view.
   *
   * @param string $cache_context
   *   The additional cache context.
   *
   * @return $this
   */
  public function addCacheContext($cache_context) {
    $this->element['#cache']['contexts'][] = $cache_context;
    return $this;
  }

  /**
   * Change/Set the current page for the pager.
   *
   * @param int $page
   *   The current page.
   */
  public function setCurrentPage($page) {
    $this->current_page = $page;

    // Calls like ::unserialize() might call this method without a proper $page.
    // Also check whether the element is pre rendered. At that point, the cache
    // keys cannot longer be manipulated.
    if ($page !== NULL && empty($this->element['#pre_rendered'])) {
      $this->element['#cache']['keys'][] = 'page:' . $page;
    }

    // If the pager is already initialized, pass it through to the pager.
    if (!empty($this->pager)) {
      return $this->pager
        ->setCurrentPage($page);
    }
  }

  /**
   * Get the current page from the pager.
   */
  public function getCurrentPage() {

    // If the pager is already initialized, pass it through to the pager.
    if (!empty($this->pager)) {
      return $this->pager
        ->getCurrentPage();
    }
    if (isset($this->current_page)) {
      return $this->current_page;
    }
  }

  /**
   * Get the items per page from the pager.
   */
  public function getItemsPerPage() {

    // If the pager is already initialized, pass it through to the pager.
    if (!empty($this->pager)) {
      return $this->pager
        ->getItemsPerPage();
    }
    if (isset($this->items_per_page)) {
      return $this->items_per_page;
    }
  }

  /**
   * Set the items per page on the pager.
   *
   * @param int $items_per_page
   *   The items per page.
   */
  public function setItemsPerPage($items_per_page) {

    // Check whether the element is pre rendered. At that point, the cache keys
    // cannot longer be manipulated.
    if (empty($this->element['#pre_rendered'])) {
      $this->element['#cache']['keys'][] = 'items_per_page:' . $items_per_page;
    }
    $this->items_per_page = $items_per_page;

    // If the pager is already initialized, pass it through to the pager.
    if (!empty($this->pager)) {
      $this->pager
        ->setItemsPerPage($items_per_page);
    }
  }

  /**
   * Get the pager offset from the pager.
   */
  public function getOffset() {

    // If the pager is already initialized, pass it through to the pager.
    if (!empty($this->pager)) {
      return $this->pager
        ->getOffset();
    }
    if (isset($this->offset)) {
      return $this->offset;
    }
  }

  /**
   * Set the offset on the pager.
   *
   * @param int $offset
   *   The pager offset.
   */
  public function setOffset($offset) {

    // Check whether the element is pre rendered. At that point, the cache keys
    // cannot longer be manipulated.
    if (empty($this->element['#pre_rendered'])) {
      $this->element['#cache']['keys'][] = 'offset:' . $offset;
    }
    $this->offset = $offset;

    // If the pager is already initialized, pass it through to the pager.
    if (!empty($this->pager)) {
      $this->pager
        ->setOffset($offset);
    }
  }

  /**
   * Determine if the pager actually uses a pager.
   */
  public function usePager() {
    if (!empty($this->pager)) {
      return $this->pager
        ->usePager();
    }
  }

  /**
   * Sets whether or not AJAX should be used.
   *
   * If AJAX is used, paging, tablesorting and exposed filters will be fetched
   * via an AJAX call rather than a page refresh.
   *
   * @param bool $use_ajax
   *   TRUE if AJAX should be used, FALSE otherwise.
   */
  public function setAjaxEnabled($ajax_enabled) {
    $this->ajaxEnabled = (bool) $ajax_enabled;
  }

  /**
   * Whether or not AJAX should be used.
   *
   * @see \Drupal\views\ViewExecutable::setAjaxEnabled().
   *
   * @return bool
   */
  public function ajaxEnabled() {
    return $this->ajaxEnabled;
  }

  /**
   * Set the exposed filters input to an array. If unset they will be taken
   * from \Drupal::request()->query when the time comes.
   */
  public function setExposedInput($filters) {
    $this->exposed_input = $filters;
  }

  /**
   * Figure out what the exposed input for this view is.
   */
  public function getExposedInput() {

    // Fill our input either from \Drupal::request()->query or from something
    // previously set on the view.
    if (empty($this->exposed_input)) {

      // Ensure that we can call the method at any point in time.
      $this
        ->initDisplay();
      $this->exposed_input = \Drupal::request()->query
        ->all();

      // unset items that are definitely not our input:
      foreach (array(
        'page',
        'q',
      ) as $key) {
        if (isset($this->exposed_input[$key])) {
          unset($this->exposed_input[$key]);
        }
      }

      // If we have no input at all, check for remembered input via session.
      // If filters are not overridden, store the 'remember' settings on the
      // default display. If they are, store them on this display. This way,
      // multiple displays in the same view can share the same filters and
      // remember settings.
      $display_id = $this->display_handler
        ->isDefaulted('filters') ? 'default' : $this->current_display;
      if (empty($this->exposed_input) && !empty($_SESSION['views'][$this->storage
        ->id()][$display_id])) {
        $this->exposed_input = $_SESSION['views'][$this->storage
          ->id()][$display_id];
      }
    }
    return $this->exposed_input;
  }

  /**
   * Set the display for this view and initialize the display handler.
   */
  public function initDisplay() {
    if (isset($this->current_display)) {
      return TRUE;
    }

    // Initialize the display cache array.
    $this->displayHandlers = new DisplayPluginCollection($this, Views::pluginManager('display'));
    $this->current_display = 'default';
    $this->display_handler = $this->displayHandlers
      ->get('default');
    return TRUE;
  }

  /**
   * Get the first display that is accessible to the user.
   *
   * @param array|string $displays
   *   Either a single display id or an array of display ids.
   *
   * @return string
   *   The first accessible display id, at least default.
   */
  public function chooseDisplay($displays) {
    if (!is_array($displays)) {
      return $displays;
    }
    $this
      ->initDisplay();
    foreach ($displays as $display_id) {
      if ($this->displayHandlers
        ->get($display_id)
        ->access($this->user)) {
        return $display_id;
      }
    }
    return 'default';
  }

  /**
   * Gets the current display plugin.
   *
   * @return \Drupal\views\Plugin\views\display\DisplayPluginBase
   */
  public function getDisplay() {
    if (!isset($this->display_handler)) {
      $this
        ->initDisplay();
    }
    return $this->display_handler;
  }

  /**
   * Sets the current display.
   *
   * @param string $display_id
   *   The ID of the display to mark as current.
   *
   * @return bool
   *   TRUE if the display was correctly set, FALSE otherwise.
   */
  public function setDisplay($display_id = NULL) {

    // If we have not already initialized the display, do so.
    if (!isset($this->current_display)) {

      // This will set the default display and instantiate the default display
      // plugin.
      $this
        ->initDisplay();
    }

    // If no display ID is passed, we either have initialized the default or
    // already have a display set.
    if (!isset($display_id)) {
      return TRUE;
    }
    $display_id = $this
      ->chooseDisplay($display_id);

    // Ensure the requested display exists.
    if (!$this->displayHandlers
      ->has($display_id)) {
      debug(format_string('setDisplay() called with invalid display ID "@display".', array(
        '@display' => $display_id,
      )));
      return FALSE;
    }

    // Reset if the display has changed. It could be called multiple times for
    // the same display, especially in the UI.
    if ($this->current_display != $display_id) {

      // Set the current display.
      $this->current_display = $display_id;

      // Reset the style and row plugins.
      $this->style_plugin = NULL;
      $this->plugin_name = NULL;
      $this->rowPlugin = NULL;
    }
    if ($display = $this->displayHandlers
      ->get($display_id)) {

      // Set a shortcut.
      $this->display_handler = $display;
      return TRUE;
    }
    return FALSE;
  }

  /**
   * Creates a new display and a display handler instance for it.
   *
   * @param string $plugin_id
   *   (optional) The plugin type from the Views plugin annotation. Defaults to
   *   'page'.
   * @param string $title
   *   (optional) The title of the display. Defaults to NULL.
   * @param string $id
   *   (optional) The ID to use, e.g., 'default', 'page_1', 'block_2'. Defaults
   *   to NULL.
   *
   * @return \Drupal\views\Plugin\views\display\DisplayPluginBase
   *   A new display plugin instance if executable is set, the new display ID
   *   otherwise.
   */
  public function newDisplay($plugin_id = 'page', $title = NULL, $id = NULL) {
    $this
      ->initDisplay();
    $id = $this->storage
      ->addDisplay($plugin_id, $title, $id);
    $this->displayHandlers
      ->addInstanceId($id);
    $display = $this->displayHandlers
      ->get($id);
    $display
      ->newDisplay();
    return $display;
  }

  /**
   * Gets the current style plugin.
   *
   * @return \Drupal\views\Plugin\views\style\StylePluginBase
   */
  public function getStyle() {
    if (!isset($this->style_plugin)) {
      $this
        ->initStyle();
    }
    return $this->style_plugin;
  }

  /**
   * Find and initialize the style plugin.
   *
   * Note that arguments may have changed which style plugin we use, so
   * check the view object first, then ask the display handler.
   */
  public function initStyle() {
    if (isset($this->style_plugin)) {
      return TRUE;
    }
    $this->style_plugin = $this->display_handler
      ->getPlugin('style');
    if (empty($this->style_plugin)) {
      return FALSE;
    }
    return TRUE;
  }

  /**
   * Acquire and attach all of the handlers.
   */
  public function initHandlers() {
    $this
      ->initDisplay();
    if (empty($this->inited)) {
      foreach ($this::getHandlerTypes() as $key => $info) {
        $this
          ->_initHandler($key, $info);
      }
      $this->inited = TRUE;
    }
  }

  /**
   * Get the current pager plugin.
   *
   * @return \Drupal\views\Plugin\views\pager\PagerPluginBase
   */
  public function getPager() {
    if (!isset($this->pager)) {
      $this
        ->initPager();
    }
    return $this->pager;
  }

  /**
   * Initialize the pager
   *
   * Like style initialization, pager initialization is held until late
   * to allow for overrides.
   */
  public function initPager() {
    if (!isset($this->pager)) {
      $this->pager = $this->display_handler
        ->getPlugin('pager');
      if ($this->pager
        ->usePager()) {
        $this->pager
          ->setCurrentPage($this->current_page);
      }

      // These overrides may have been set earlier via $view->set_*
      // functions.
      if (isset($this->items_per_page)) {
        $this->pager
          ->setItemsPerPage($this->items_per_page);
      }
      if (isset($this->offset)) {
        $this->pager
          ->setOffset($this->offset);
      }
    }
  }

  /**
   * Render the pager, if necessary.
   */
  public function renderPager($exposed_input) {
    if (!empty($this->pager) && $this->pager
      ->usePager()) {
      return $this->pager
        ->render($exposed_input);
    }
    return '';
  }

  /**
   * Create a list of base tables eligible for this view. Used primarily
   * for the UI. Display must be already initialized.
   */
  public function getBaseTables() {
    $base_tables = array(
      $this->storage
        ->get('base_table') => TRUE,
      '#global' => TRUE,
    );
    foreach ($this->display_handler
      ->getHandlers('relationship') as $handler) {
      $base_tables[$handler->definition['base']] = TRUE;
    }
    return $base_tables;
  }

  /**
   * Run the preQuery() on all active handlers.
   */
  protected function _preQuery() {
    foreach ($this::getHandlerTypes() as $key => $info) {
      $handlers =& $this->{$key};
      $position = 0;
      foreach ($handlers as $id => $handler) {
        $handlers[$id]->position = $position;
        $handlers[$id]
          ->preQuery();
        $position++;
      }
    }
  }

  /**
   * Run the postExecute() on all active handlers.
   */
  protected function _postExecute() {
    foreach ($this::getHandlerTypes() as $key => $info) {
      $handlers =& $this->{$key};
      foreach ($handlers as $id => $handler) {
        $handlers[$id]
          ->postExecute($this->result);
      }
    }
  }

  /**
   * Attach all of the handlers for each type.
   *
   * @param $key
   *   One of 'argument', 'field', 'sort', 'filter', 'relationship'
   * @param $info
   *   The $info from getHandlerTypes for this object.
   */
  protected function _initHandler($key, $info) {

    // Load the requested items from the display onto the object.
    $this->{$key} =& $this->display_handler
      ->getHandlers($key);

    // This reference deals with difficult PHP indirection.
    $handlers =& $this->{$key};

    // Run through and test for accessibility.
    foreach ($handlers as $id => $handler) {
      if (!$handler
        ->access($this->user)) {
        unset($handlers[$id]);
      }
    }
  }

  /**
   * Build all the arguments.
   */
  protected function _buildArguments() {

    // Initially, we want to build sorts and fields. This can change, though,
    // if we get a summary view.
    if (empty($this->argument)) {
      return TRUE;
    }

    // build arguments.
    $position = -1;
    $substitutions = array();
    $status = TRUE;

    // Get the title.
    $title = $this->display_handler
      ->getOption('title');

    // Iterate through each argument and process.
    foreach ($this->argument as $id => $arg) {
      $position++;
      $argument = $this->argument[$id];
      if ($argument
        ->broken()) {
        continue;
      }
      $argument
        ->setRelationship();
      $arg = isset($this->args[$position]) ? $this->args[$position] : NULL;
      $argument->position = $position;
      if (isset($arg) || $argument
        ->hasDefaultArgument()) {
        if (!isset($arg)) {
          $arg = $argument
            ->getDefaultArgument();

          // make sure default args get put back.
          if (isset($arg)) {
            $this->args[$position] = $arg;
          }

          // remember that this argument was computed, not passed on the URL.
          $argument->is_default = TRUE;
        }

        // Set the argument, which will also validate that the argument can be set.
        if (!$argument
          ->setArgument($arg)) {
          $status = $argument
            ->validateFail($arg);
          break;
        }
        if ($argument
          ->isException()) {
          $arg_title = $argument
            ->exceptionTitle();
        }
        else {
          $arg_title = $argument
            ->getTitle();
          $argument
            ->query($this->display_handler
            ->useGroupBy());
        }

        // Add this argument's substitution
        $substitutions["{{ arguments.{$id} }}"] = $arg_title;
        $substitutions["{{ raw_arguments.{$id} }}"] = strip_tags(Html::decodeEntities($arg));

        // Test to see if we should use this argument's title
        if (!empty($argument->options['title_enable']) && !empty($argument->options['title'])) {
          $title = $argument->options['title'];
        }
      }
      else {

        // determine default condition and handle.
        $status = $argument
          ->defaultAction();
        break;
      }

      // Be safe with references and loops:
      unset($argument);
    }

    // set the title in the build info.
    if (!empty($title)) {
      $this->build_info['title'] = $title;
    }

    // Store the arguments for later use.
    $this->build_info['substitutions'] = $substitutions;
    return $status;
  }

  /**
   * Gets the current query plugin.
   *
   * @return \Drupal\views\Plugin\views\query\QueryPluginBase
   */
  public function getQuery() {
    if (!isset($this->query)) {
      $this
        ->initQuery();
    }
    return $this->query;
  }

  /**
   * Do some common building initialization.
   */
  public function initQuery() {
    if (!empty($this->query)) {
      $class = get_class($this->query);
      if ($class && $class != 'stdClass') {

        // return if query is already initialized.
        return TRUE;
      }
    }

    // Create and initialize the query object.
    $views_data = Views::viewsData()
      ->get($this->storage
      ->get('base_table'));
    $this->storage
      ->set('base_field', !empty($views_data['table']['base']['field']) ? $views_data['table']['base']['field'] : '');
    if (!empty($views_data['table']['base']['database'])) {
      $this->base_database = $views_data['table']['base']['database'];
    }
    $this->query = $this->display_handler
      ->getPlugin('query');
    return TRUE;
  }

  /**
   * Build the query for the view.
   */
  public function build($display_id = NULL) {
    if (!empty($this->built)) {
      return;
    }
    if (empty($this->current_display) || $display_id) {
      if (!$this
        ->setDisplay($display_id)) {
        return FALSE;
      }
    }

    // Let modules modify the view just prior to building it.
    $module_handler = \Drupal::moduleHandler();
    $module_handler
      ->invokeAll('views_pre_build', array(
      $this,
    ));

    // Attempt to load from cache.
    // @todo Load a build_info from cache.
    $start = microtime(TRUE);

    // If that fails, let's build!
    $this->build_info = array(
      'query' => '',
      'count_query' => '',
      'query_args' => array(),
    );
    $this
      ->initQuery();

    // Call a module hook and see if it wants to present us with a
    // pre-built query or instruct us not to build the query for
    // some reason.
    // @todo: Implement this. Use the same mechanism Panels uses.
    // Run through our handlers and ensure they have necessary information.
    $this
      ->initHandlers();

    // Let the handlers interact with each other if they really want.
    $this
      ->_preQuery();
    if ($this->display_handler
      ->usesExposed()) {
      $exposed_form = $this->display_handler
        ->getPlugin('exposed_form');
      $this->exposed_widgets = $exposed_form
        ->renderExposedForm();
      if (FormState::hasAnyErrors() || !empty($this->build_info['abort'])) {
        $this->built = TRUE;

        // Don't execute the query, $form_state, but rendering will still be executed to display the empty text.
        $this->executed = TRUE;
        return empty($this->build_info['fail']);
      }
    }

    // Build all the relationships first thing.
    $this
      ->_build('relationship');

    // Set the filtering groups.
    if (!empty($this->filter)) {
      $filter_groups = $this->display_handler
        ->getOption('filter_groups');
      if ($filter_groups) {
        $this->query
          ->setGroupOperator($filter_groups['operator']);
        foreach ($filter_groups['groups'] as $id => $operator) {
          $this->query
            ->setWhereGroup($operator, $id);
        }
      }
    }

    // Build all the filters.
    $this
      ->_build('filter');
    $this->build_sort = TRUE;

    // Arguments can, in fact, cause this whole thing to abort.
    if (!$this
      ->_buildArguments()) {
      $this->build_time = microtime(TRUE) - $start;
      $this
        ->attachDisplays();
      return $this->built;
    }

    // Initialize the style; arguments may have changed which style we use,
    // so waiting as long as possible is important. But we need to know
    // about the style when we go to build fields.
    if (!$this
      ->initStyle()) {
      $this->build_info['fail'] = TRUE;
      return FALSE;
    }
    if ($this->style_plugin
      ->usesFields()) {
      $this
        ->_build('field');
    }

    // Build our sort criteria if we were instructed to do so.
    if (!empty($this->build_sort)) {

      // Allow the style handler to deal with sorting.
      if ($this->style_plugin
        ->buildSort()) {
        $this
          ->_build('sort');
      }

      // allow the plugin to build second sorts as well.
      $this->style_plugin
        ->buildSortPost();
    }

    // Allow area handlers to affect the query.
    $this
      ->_build('header');
    $this
      ->_build('footer');
    $this
      ->_build('empty');

    // Allow display handler to affect the query:
    $this->display_handler
      ->query($this->display_handler
      ->useGroupBy());

    // Allow style handler to affect the query:
    $this->style_plugin
      ->query($this->display_handler
      ->useGroupBy());

    // Allow exposed form to affect the query:
    if (isset($exposed_form)) {
      $exposed_form
        ->query();
    }
    if (\Drupal::config('views.settings')
      ->get('sql_signature')) {
      $this->query
        ->addSignature($this);
    }

    // Let modules modify the query just prior to finalizing it.
    $this->query
      ->alter($this);

    // Only build the query if we weren't interrupted.
    if (empty($this->built)) {

      // Build the necessary info to execute the query.
      $this->query
        ->build($this);
    }
    $this->built = TRUE;
    $this->build_time = microtime(TRUE) - $start;

    // Attach displays
    $this
      ->attachDisplays();

    // Let modules modify the view just after building it.
    $module_handler
      ->invokeAll('views_post_build', array(
      $this,
    ));
    return TRUE;
  }

  /**
   * Internal method to build an individual set of handlers.
   *
   * @todo Some filter needs this function, even it is internal.
   *
   * @param string $key
   *    The type of handlers (filter etc.) which should be iterated over to
   *    build the relationship and query information.
   */
  public function _build($key) {
    $handlers =& $this->{$key};
    foreach ($handlers as $id => $data) {
      if (!empty($handlers[$id]) && is_object($handlers[$id])) {
        $multiple_exposed_input = array(
          0 => NULL,
        );
        if ($handlers[$id]
          ->multipleExposedInput()) {
          $multiple_exposed_input = $handlers[$id]
            ->groupMultipleExposedInput($this->exposed_data);
        }
        foreach ($multiple_exposed_input as $group_id) {

          // Give this handler access to the exposed filter input.
          if (!empty($this->exposed_data)) {
            if ($handlers[$id]
              ->isAGroup()) {
              $converted = $handlers[$id]
                ->convertExposedInput($this->exposed_data, $group_id);
              $handlers[$id]
                ->storeGroupInput($this->exposed_data, $converted);
              if (!$converted) {
                continue;
              }
            }
            $rc = $handlers[$id]
              ->acceptExposedInput($this->exposed_data);
            $handlers[$id]
              ->storeExposedInput($this->exposed_data, $rc);
            if (!$rc) {
              continue;
            }
          }
          $handlers[$id]
            ->setRelationship();
          $handlers[$id]
            ->query($this->display_handler
            ->useGroupBy());
        }
      }
    }
  }

  /**
   * Execute the view's query.
   *
   * @param string $display_id
   *   The machine name of the display, which should be executed.
   *
   * @return bool
   *   Return whether the executing was successful, for example an argument
   *   could stop the process.
   */
  public function execute($display_id = NULL) {
    if (empty($this->built)) {
      if (!$this
        ->build($display_id)) {
        return FALSE;
      }
    }
    if (!empty($this->executed)) {
      return TRUE;
    }

    // Don't allow to use deactivated displays, but display them on the live preview.
    if (!$this->display_handler
      ->isEnabled() && empty($this->live_preview)) {
      $this->build_info['fail'] = TRUE;
      return FALSE;
    }

    // Let modules modify the view just prior to executing it.
    $module_handler = \Drupal::moduleHandler();
    $module_handler
      ->invokeAll('views_pre_execute', array(
      $this,
    ));

    // Check for already-cached results.
    if (!empty($this->live_preview)) {
      $cache = $this->display_handler
        ->getPlugin('cache', 'none');
    }
    else {
      $cache = $this->display_handler
        ->getPlugin('cache');
    }
    if ($cache
      ->cacheGet('results')) {
      if ($this->pager
        ->usePager()) {
        $this->pager->total_items = $this->total_rows;
        $this->pager
          ->updatePageInfo();
      }
    }
    else {
      $this->query
        ->execute($this);

      // Enforce the array key rule as documented in
      // views_plugin_query::execute().
      $this->result = array_values($this->result);
      $this
        ->_postExecute();
      $cache
        ->cacheSet('results');
    }

    // Let modules modify the view just after executing it.
    $module_handler
      ->invokeAll('views_post_execute', array(
      $this,
    ));
    $this->executed = TRUE;
  }

  /**
   * Render this view for a certain display.
   *
   * Note: You should better use just the preview function if you want to
   * render a view.
   *
   * @param string $display_id
   *   The machine name of the display, which should be rendered.
   *
   * @return string|null
   *   Return the output of the rendered view or NULL if something failed in the process.
   */
  public function render($display_id = NULL) {
    $this
      ->execute($display_id);

    // Check to see if the build failed.
    if (!empty($this->build_info['fail'])) {
      return;
    }
    if (!empty($this->build_info['denied'])) {
      return;
    }
    $exposed_form = $this->display_handler
      ->getPlugin('exposed_form');
    $exposed_form
      ->preRender($this->result);
    $module_handler = \Drupal::moduleHandler();

    // @TODO In the longrun, it would be great to execute a view without
    //   the theme system at all. See https://www.drupal.org/node/2322623.
    $active_theme = \Drupal::theme()
      ->getActiveTheme();
    $themes = array_keys($active_theme
      ->getBaseThemes());
    $themes[] = $active_theme
      ->getName();

    // Check for already-cached output.

    /** @var \Drupal\views\Plugin\views\cache\CachePluginBase $cache */
    if (!empty($this->live_preview)) {
      $cache = Views::pluginManager('cache')
        ->createInstance('none');
    }
    else {
      $cache = $this->display_handler
        ->getPlugin('cache');
    }

    // Run preRender for the pager as it might change the result.
    if (!empty($this->pager)) {
      $this->pager
        ->preRender($this->result);
    }

    // Initialize the style plugin.
    $this
      ->initStyle();
    if (!isset($this->response)) {

      // Set the response so other parts can alter it.
      $this->response = new Response('', 200);
    }

    // Give field handlers the opportunity to perform additional queries
    // using the entire resultset prior to rendering.
    if ($this->style_plugin
      ->usesFields()) {
      foreach ($this->field as $id => $handler) {
        if (!empty($this->field[$id])) {
          $this->field[$id]
            ->preRender($this->result);
        }
      }
    }
    $this->style_plugin
      ->preRender($this->result);

    // Let each area handler have access to the result set.
    $areas = array(
      'header',
      'footer',
    );

    // Only call preRender() on the empty handlers if the result is empty.
    if (empty($this->result)) {
      $areas[] = 'empty';
    }
    foreach ($areas as $area) {
      foreach ($this->{$area} as $handler) {
        $handler
          ->preRender($this->result);
      }
    }

    // Let modules modify the view just prior to rendering it.
    $module_handler
      ->invokeAll('views_pre_render', array(
      $this,
    ));

    // Let the themes play too, because pre render is a very themey thing.
    foreach ($themes as $theme_name) {
      $function = $theme_name . '_views_pre_render';
      if (function_exists($function)) {
        $function($this);
      }
    }
    $this->display_handler->output = $this->display_handler
      ->render();
    $exposed_form
      ->postRender($this->display_handler->output);
    $cache
      ->postRender($this->display_handler->output);

    // Let modules modify the view output after it is rendered.
    $module_handler
      ->invokeAll('views_post_render', array(
      $this,
      &$this->display_handler->output,
      $cache,
    ));

    // Let the themes play too, because post render is a very themey thing.
    foreach ($themes as $theme_name) {
      $function = $theme_name . '_views_post_render';
      if (function_exists($function)) {
        $function($this, $this->display_handler->output, $cache);
      }
    }
    return $this->display_handler->output;
  }

  /**
   * Gets the cache tags associated with the executed view.
   *
   * Note: The cache plugin controls the used tags, so you can override it, if
   *   needed.
   *
   * @return string[]
   *   An array of cache tags.
   */
  public function getCacheTags() {
    $this
      ->initDisplay();

    /** @var \Drupal\views\Plugin\views\cache\CachePluginBase $cache */
    $cache = $this->display_handler
      ->getPlugin('cache');
    return $cache
      ->getCacheTags();
  }

  /**
   * Builds the render array outline for the given display.
   *
   * This render array has a #pre_render callback which will call
   * ::executeDisplay in order to actually execute the view and then build the
   * final render array structure.
   *
   * @param string $display_id
   *   The display ID.
   * @param array $args
   *   An array of arguments passed along to the view.
   * @param bool $cache
   *   (optional) Should the result be render cached.
   *
   * @return array|null
   *   A renderable array with #type 'view' or NULL if the display ID was
   *   invalid.
   */
  public function buildRenderable($display_id = NULL, $args = array(), $cache = TRUE) {

    // @todo Extract that into a generic method.
    if (empty($this->current_display) || $this->current_display != $this
      ->chooseDisplay($display_id)) {
      if (!$this
        ->setDisplay($display_id)) {
        return NULL;
      }
    }
    return $this->display_handler
      ->buildRenderable($args, $cache);
  }

  /**
   * Execute the given display, with the given arguments.
   * To be called externally by whatever mechanism invokes the view,
   * such as a page callback, hook_block, etc.
   *
   * This function should NOT be used by anything external as this
   * returns data in the format specified by the display. It can also
   * have other side effects that are only intended for the 'proper'
   * use of the display, such as setting page titles.
   *
   * If you simply want to view the display, use View::preview() instead.
   */
  public function executeDisplay($display_id = NULL, $args = array()) {
    if (empty($this->current_display) || $this->current_display != $this
      ->chooseDisplay($display_id)) {
      if (!$this
        ->setDisplay($display_id)) {
        return NULL;
      }
    }
    $this
      ->preExecute($args);

    // Execute the view
    $output = $this->display_handler
      ->execute();
    $this
      ->postExecute();
    return $output;
  }

  /**
   * Preview the given display, with the given arguments.
   *
   * To be called externally, probably by an AJAX handler of some flavor.
   * Can also be called when views are embedded, as this guarantees
   * normalized output.
   *
   * This function does not do any access checks on the view. It is the
   * responsibility of the caller to check $view->access() or implement other
   * access logic. To render the view normally with access checks, use
   * views_embed_view() instead.
   */
  public function preview($display_id = NULL, $args = array()) {
    if (empty($this->current_display) || !empty($display_id) && $this->current_display != $display_id) {
      if (!$this
        ->setDisplay($display_id)) {
        return FALSE;
      }
    }
    $this->preview = TRUE;
    $this
      ->preExecute($args);

    // Preview the view.
    $output = $this->display_handler
      ->preview();
    $this
      ->postExecute();
    return $output;
  }

  /**
   * Run attachments and let the display do what it needs to do prior
   * to running.
   */
  public function preExecute($args = array()) {
    $this->old_view[] = views_get_current_view();
    views_set_current_view($this);
    $display_id = $this->current_display;

    // Prepare the view with the information we have, but only if we were
    // passed arguments, as they may have been set previously.
    if ($args) {
      $this
        ->setArguments($args);
    }

    // Let modules modify the view just prior to executing it.
    \Drupal::moduleHandler()
      ->invokeAll('views_pre_view', array(
      $this,
      $display_id,
      &$this->args,
    ));

    // Allow hook_views_pre_view() to set the dom_id, then ensure it is set.
    $this->dom_id = !empty($this->dom_id) ? $this->dom_id : hash('sha256', $this->storage
      ->id() . REQUEST_TIME . mt_rand());

    // Allow the display handler to set up for execution
    $this->display_handler
      ->preExecute();
  }

  /**
   * Unset the current view, mostly.
   */
  public function postExecute() {

    // unset current view so we can be properly destructed later on.
    // Return the previous value in case we're an attachment.
    if ($this->old_view) {
      $old_view = array_pop($this->old_view);
    }
    views_set_current_view(isset($old_view) ? $old_view : FALSE);
  }

  /**
   * Run attachment displays for the view.
   */
  public function attachDisplays() {
    if (!empty($this->is_attachment)) {
      return;
    }
    if (!$this->display_handler
      ->acceptAttachments()) {
      return;
    }
    $this->is_attachment = TRUE;

    // Find out which other displays attach to the current one.
    foreach ($this->display_handler
      ->getAttachedDisplays() as $id) {
      $display_handler = $this->displayHandlers
        ->get($id);

      // Only attach enabled attachments.
      if ($display_handler
        ->isEnabled()) {
        $cloned_view = Views::executableFactory()
          ->get($this->storage);
        $display_handler
          ->attachTo($cloned_view, $this->current_display, $this->element);
      }
    }
    $this->is_attachment = FALSE;
  }

  /**
   * Determine if the given user has access to the view. Note that
   * this sets the display handler if it hasn't been.
   */
  public function access($displays = NULL, $account = NULL) {

    // No one should have access to disabled views.
    if (!$this->storage
      ->status()) {
      return FALSE;
    }
    if (!isset($this->current_display)) {
      $this
        ->initDisplay();
    }
    if (!$account) {
      $account = $this->user;
    }

    // We can't use choose_display() here because that function
    // calls this one.
    $displays = (array) $displays;
    foreach ($displays as $display_id) {
      if ($this->displayHandlers
        ->has($display_id)) {
        if (($display = $this->displayHandlers
          ->get($display_id)) && $display
          ->access($account)) {
          return TRUE;
        }
      }
    }
    return FALSE;
  }

  /**
   * Sets the used response object of the view.
   *
   * @param \Symfony\Component\HttpFoundation\Response $response
   *   The response object which should be set.
   */
  public function setResponse(Response $response) {
    $this->response = $response;
  }

  /**
   * Gets the response object used by the view.
   *
   * @return \Symfony\Component\HttpFoundation\Response
   *   The response object of the view.
   */
  public function getResponse() {
    if (!isset($this->response)) {
      $this->response = new Response();
    }
    return $this->response;
  }

  /**
   * Sets the request object.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The request object.
   */
  public function setRequest(Request $request) {
    $this->request = $request;
  }

  /**
   * Gets the request object.
   *
   * @return \Symfony\Component\HttpFoundation\Request $request
   *   Returns the request object.
   */
  public function getRequest() {
    return $this->request;
  }

  /**
   * Get the view's current title. This can change depending upon how it
   * was built.
   */
  public function getTitle() {
    if (empty($this->display_handler)) {
      if (!$this
        ->setDisplay('default')) {
        return FALSE;
      }
    }

    // During building, we might find a title override. If so, use it.
    if (!empty($this->build_info['title'])) {
      $title = $this->build_info['title'];
    }
    else {
      $title = $this->display_handler
        ->getOption('title');
    }

    // Allow substitutions from the first row.
    if ($this
      ->initStyle()) {
      $title = $this->style_plugin
        ->tokenizeValue($title, 0);
    }
    return $title;
  }

  /**
   * Override the view's current title.
   *
   * The tokens in the title get's replaced before rendering.
   */
  public function setTitle($title) {
    $this->build_info['title'] = $title;
    return TRUE;
  }

  /**
   * Force the view to build a title.
   */
  public function buildTitle() {
    $this
      ->initDisplay();
    if (empty($this->built)) {
      $this
        ->initQuery();
    }
    $this
      ->initHandlers();
    $this
      ->_buildArguments();
  }

  /**
   * Determines whether you can link to the view or a particular display.
   *
   * Some displays (e.g. block displays) do not have their own route, but may
   * optionally provide a link to another display that does have a route.
   *
   * @param array $args
   *   (optional) The arguments.
   * @param string $display_id
   *   (optional) The display ID. The current display will be used by default.
   *
   * @return bool
   */
  public function hasUrl($args = NULL, $display_id = NULL) {
    if (!empty($this->override_url)) {
      return TRUE;
    }

    // If the display has a valid route available (either its own or for a
    // linked display), then we can provide a URL for it.
    $display_handler = $this->displayHandlers
      ->get($display_id ?: $this->current_display)
      ->getRoutedDisplay();
    if (!$display_handler instanceof DisplayRouterInterface) {
      return FALSE;
    }

    // Look up the route name to make sure it exists.  The name may exist, but
    // not be available yet in some instances when editing a view and doing
    // a live preview.
    $provider = \Drupal::service('router.route_provider');
    try {
      $provider
        ->getRouteByName($display_handler
        ->getRouteName());
    } catch (RouteNotFoundException $e) {
      return FALSE;
    }
    return TRUE;
  }

  /**
   * Get the URL for the current view.
   *
   * This URL will be adjusted for arguments.
   *
   * @param array $args
   *   (optional) Passed in arguments.
   * @param string $display_id
   *   (optional) Specify the display ID to link to, fallback to the current ID.
   *
   * @return \Drupal\Core\Url
   */
  public function getUrl($args = NULL, $display_id = NULL) {
    if (!empty($this->override_url)) {
      return $this->override_url;
    }
    if (!isset($path)) {
      $path = $this
        ->getPath();
    }
    $display_handler = $this->displayHandlers
      ->get($display_id ?: $this->current_display)
      ->getRoutedDisplay();
    if (!$display_handler instanceof DisplayRouterInterface) {
      throw new \InvalidArgumentException('You cannot create a URL to a display without routes.');
    }
    if (!isset($args)) {
      $args = $this->args;

      // Exclude arguments that were computed, not passed on the URL.
      $position = 0;
      if (!empty($this->argument)) {
        foreach ($this->argument as $argument) {
          if (!empty($argument->is_default) && !empty($argument->options['default_argument_skip_url'])) {
            unset($args[$position]);
          }
          $position++;
        }
      }
    }

    // Don't bother working if there's nothing to do:
    if (empty($path) || empty($args) && strpos($path, '%') === FALSE) {
      return $display_handler
        ->getUrlInfo();
    }
    $argument_keys = isset($this->argument) ? array_keys($this->argument) : array();
    $id = current($argument_keys);

    /** @var \Drupal\Core\Url $url */
    $url = $display_handler
      ->getUrlInfo();
    $route = $this->routeProvider
      ->getRouteByName($url
      ->getRouteName());
    $variables = $route
      ->compile()
      ->getVariables();
    $parameters = $url
      ->getRouteParameters();
    foreach ($variables as $variable_name) {
      if (empty($args)) {

        // Try to never put % in a URL; use the wildcard instead.
        if ($id && !empty($this->argument[$id]->options['exception']['value'])) {
          $parameters[$variable_name] = $this->argument[$id]->options['exception']['value'];
        }
        else {

          // Provide some fallback in case no exception value could be found.
          $parameters[$variable_name] = '*';
        }
      }
      else {
        $parameters[$variable_name] = array_shift($args);
      }
      if ($id) {
        $id = next($argument_keys);
      }
    }
    $url
      ->setRouteParameters($parameters);
    return $url;
  }

  /**
   * Gets the Url object associated with the display handler.
   *
   * @param string $display_id
   *   (Optional) The display id. ( Used only to detail an exception. )
   *
   * @return \Drupal\Core\Url
   *   The display handlers URL object.
   *
   * @throws \InvalidArgumentException
   *   Thrown when the display plugin does not have a URL to return.
   */
  public function getUrlInfo($display_id = '') {
    $this
      ->initDisplay();
    if (!$this->display_handler instanceof DisplayRouterInterface) {
      throw new \InvalidArgumentException("You cannot generate a URL for the display '{$display_id}'");
    }
    return $this->display_handler
      ->getUrlInfo();
  }

  /**
   * Get the base path used for this view.
   */
  public function getPath() {
    if (!empty($this->override_path)) {
      return $this->override_path;
    }
    if (empty($this->display_handler)) {
      if (!$this
        ->setDisplay('default')) {
        return FALSE;
      }
    }
    return $this->display_handler
      ->getPath();
  }

  /**
   * Gets the current user.
   *
   * Views plugins can receive the current user in order to not need dependency
   * injection.
   *
   * @return \Drupal\Core\Session\AccountInterface
   */
  public function getUser() {
    return $this->user;
  }

  /**
   * Creates a duplicate ViewExecutable object.
   *
   * Makes a copy of this view that has been sanitized of handlers, any runtime
   * data, ID, and UUID.
   */
  public function createDuplicate() {
    return $this->storage
      ->createDuplicate()
      ->getExecutable();
  }

  /**
   * Unset references so that a $view object may be properly garbage
   * collected.
   */
  public function destroy() {
    foreach ($this::getHandlerTypes() as $type => $info) {
      if (isset($this->{$type})) {
        foreach ($this->{$type} as $handler) {
          $handler
            ->destroy();
        }
      }
    }
    if (isset($this->style_plugin)) {
      $this->style_plugin
        ->destroy();
    }
    $reflection = new \ReflectionClass($this);
    $defaults = $reflection
      ->getDefaultProperties();

    // The external dependencies should not be reset. This is not generated by
    // the execution of a view.
    unset($defaults['storage'], $defaults['user'], $defaults['request'], $defaults['routeProvider']);
    foreach ($defaults as $property => $default) {
      $this->{$property} = $default;
    }
  }

  /**
   * Makes sure the view is completely valid.
   *
   * @return array
   *   An array of error strings. This will be empty if there are no validation
   *   errors.
   */
  public function validate() {
    $errors = array();
    $this
      ->initDisplay();
    $current_display = $this->current_display;
    foreach ($this->displayHandlers as $id => $display) {
      if (!empty($display)) {
        if (!empty($display->display['deleted'])) {
          continue;
        }
        $result = $this->displayHandlers
          ->get($id)
          ->validate();
        if (!empty($result) && is_array($result)) {
          $errors[$id] = $result;
        }
      }
    }
    $this
      ->setDisplay($current_display);
    return $errors;
  }

  /**
   * Provide a list of views handler types used in a view, with some information
   * about them.
   *
   * @return array
   *   An array of associative arrays containing:
   *   - title: The title of the handler type.
   *   - ltitle: The lowercase title of the handler type.
   *   - stitle: A singular title of the handler type.
   *   - lstitle: A singular lowercase title of the handler type.
   *   - plural: Plural version of the handler type.
   *   - (optional) type: The actual internal used handler type. This key is
   *     just used for header,footer,empty to link to the internal type: area.
   */
  public static function getHandlerTypes() {
    return Views::getHandlerTypes();
  }

  /**
   * Returns the valid types of plugins that can be used.
   *
   * @return array
   *   An array of plugin type strings.
   */
  public static function getPluginTypes($type = NULL) {
    return Views::getPluginTypes($type);
  }

  /**
   * Adds an instance of a handler to the view.
   *
   * Items may be fields, filters, sort criteria, or arguments.
   *
   * @param string $display_id
   *   The machine name of the display.
   * @param string $type
   *   The type of handler being added.
   * @param string $table
   *   The name of the table this handler is from.
   * @param string $field
   *   The name of the field this handler is from.
   * @param array $options
   *   (optional) Extra options for this instance. Defaults to an empty array.
   * @param string $id
   *   (optional) A unique ID for this handler instance. Defaults to NULL, in
   *   which case one will be generated.
   *
   * @return string
   *   The unique ID for this handler instance.
   */
  public function addHandler($display_id, $type, $table, $field, $options = array(), $id = NULL) {
    $types = $this::getHandlerTypes();
    $this
      ->setDisplay($display_id);
    $data = $this->viewsData
      ->get($table);
    $fields = $this->displayHandlers
      ->get($display_id)
      ->getOption($types[$type]['plural']);
    if (empty($id)) {
      $id = $this
        ->generateHandlerId($field, $fields);
    }

    // If the desired type is not found, use the original value directly.
    $handler_type = !empty($types[$type]['type']) ? $types[$type]['type'] : $type;
    $fields[$id] = array(
      'id' => $id,
      'table' => $table,
      'field' => $field,
    ) + $options;
    if (isset($data['table']['entity type'])) {
      $fields[$id]['entity_type'] = $data['table']['entity type'];
    }
    if (isset($data[$field]['entity field'])) {
      $fields[$id]['entity_field'] = $data[$field]['entity field'];
    }

    // Load the plugin ID if available.
    if (isset($data[$field][$handler_type]['id'])) {
      $fields[$id]['plugin_id'] = $data[$field][$handler_type]['id'];
    }
    $this->displayHandlers
      ->get($display_id)
      ->setOption($types[$type]['plural'], $fields);
    return $id;
  }

  /**
   * Generates a unique ID for an handler instance.
   *
   * These handler instances are typically fields, filters, sort criteria, or
   * arguments.
   *
   * @param string $requested_id
   *   The requested ID for the handler instance.
   * @param array $existing_items
   *   An array of existing handler instances, keyed by their IDs.
   *
   * @return string
   *   A unique ID. This will be equal to $requested_id if no handler instance
   *   with that ID already exists. Otherwise, it will be appended with an
   *   integer to make it unique, e.g., "{$requested_id}_1",
   *   "{$requested_id}_2", etc.
   */
  public static function generateHandlerId($requested_id, $existing_items) {
    $count = 0;
    $id = $requested_id;
    while (!empty($existing_items[$id])) {
      $id = $requested_id . '_' . ++$count;
    }
    return $id;
  }

  /**
   * Gets an array of handler instances for the current display.
   *
   * @param string $type
   *   The type of handlers to retrieve.
   * @param string $display_id
   *   (optional) A specific display machine name to use. If NULL, the current
   *   display will be used.
   *
   * @return array
   *   An array of handler instances of a given type for this display.
   */
  public function getHandlers($type, $display_id = NULL) {
    $old_display_id = !empty($this->current_display) ? $this->current_display : 'default';
    $this
      ->setDisplay($display_id);
    if (!isset($display_id)) {
      $display_id = $this->current_display;
    }

    // Get info about the types so we can get the right data.
    $types = static::getHandlerTypes();
    $handlers = $this->displayHandlers
      ->get($display_id)
      ->getOption($types[$type]['plural']);

    // Restore initial display id (if any) or set to 'default'.
    if ($display_id != $old_display_id) {
      $this
        ->setDisplay($old_display_id);
    }
    return $handlers;
  }

  /**
   * Gets the configuration of a handler instance on a given display.
   *
   * @param string $display_id
   *   The machine name of the display.
   * @param string $type
   *   The type of handler to retrieve.
   * @param string $id
   *   The ID of the handler to retrieve.
   *
   * @return array|null
   *   Either the handler instance's configuration, or NULL if the handler is
   *   not used on the display.
   */
  public function getHandler($display_id, $type, $id) {

    // Get info about the types so we can get the right data.
    $types = static::getHandlerTypes();

    // Initialize the display
    $this
      ->setDisplay($display_id);

    // Get the existing configuration
    $fields = $this->displayHandlers
      ->get($display_id)
      ->getOption($types[$type]['plural']);
    return isset($fields[$id]) ? $fields[$id] : NULL;
  }

  /**
   * Sets the configuration of a handler instance on a given display.
   *
   * @param string $display_id
   *   The machine name of the display.
   * @param string $type
   *   The type of handler being set.
   * @param string $id
   *   The ID of the handler being set.
   * @param array|null $item
   *   An array of configuration for a handler, or NULL to remove this instance.
   *
   * @see set_item_option()
   */
  public function setHandler($display_id, $type, $id, $item) {

    // Get info about the types so we can get the right data.
    $types = static::getHandlerTypes();

    // Initialize the display.
    $this
      ->setDisplay($display_id);

    // Get the existing configuration.
    $fields = $this->displayHandlers
      ->get($display_id)
      ->getOption($types[$type]['plural']);
    if (isset($item)) {
      $fields[$id] = $item;
    }

    // Store.
    $this->displayHandlers
      ->get($display_id)
      ->setOption($types[$type]['plural'], $fields);
  }

  /**
   * Removes configuration for a handler instance on a given display.
   *
   * @param string $display_id
   *   The machine name of the display.
   * @param string $type
   *   The type of handler being removed.
   * @param string $id
   *   The ID of the handler being removed.
   */
  public function removeHandler($display_id, $type, $id) {

    // Get info about the types so we can get the right data.
    $types = static::getHandlerTypes();

    // Initialize the display.
    $this
      ->setDisplay($display_id);

    // Get the existing configuration.
    $fields = $this->displayHandlers
      ->get($display_id)
      ->getOption($types[$type]['plural']);

    // Unset the item.
    unset($fields[$id]);

    // Store.
    $this->displayHandlers
      ->get($display_id)
      ->setOption($types[$type]['plural'], $fields);
  }

  /**
   * Sets an option on a handler instance.
   *
   * Use this only if you have just 1 or 2 options to set; if you have many,
   * consider getting the handler instance, adding the options and using
   * set_item() directly.
   *
   * @param string $display_id
   *   The machine name of the display.
   * @param string $type
   *   The type of handler being set.
   * @param string $id
   *   The ID of the handler being set.
   * @param string $option
   *   The configuration key for the value being set.
   * @param mixed $value
   *   The value being set.
   *
   * @see set_item()
   */
  public function setHandlerOption($display_id, $type, $id, $option, $value) {
    $item = $this
      ->getHandler($display_id, $type, $id);
    $item[$option] = $value;
    $this
      ->setHandler($display_id, $type, $id, $item);
  }

  /**
   * Enables admin links on the rendered view.
   *
   * @param bool $show_admin_links
   *   TRUE if the admin links should be shown.
   */
  public function setShowAdminLinks($show_admin_links) {
    $this->showAdminLinks = (bool) $show_admin_links;
  }

  /**
   * Returns whether admin links should be rendered on the view.
   *
   * @return bool
   *  Returns TRUE if admin links should be rendered, else FALSE.
   */
  public function getShowAdminLinks() {
    if (!isset($this->showAdminLinks)) {
      return $this
        ->getDisplay()
        ->getOption('show_admin_links');
    }
    return $this->showAdminLinks;
  }

  /**
   * Merges all plugin default values for each display.
   */
  public function mergeDefaults() {
    $this
      ->initDisplay();

    // Initialize displays and merge all plugin defaults.
    foreach ($this->displayHandlers as $display) {
      $display
        ->mergeDefaults();
    }
  }

  /**
   * Provide a full array of possible theme functions to try for a given hook.
   *
   * @param string $hook
   *   The hook to use. This is the base theme/template name.
   *
   * @return array
   *   An array of theme hook suggestions.
   */
  public function buildThemeFunctions($hook) {
    $themes = array();
    $display = isset($this->display_handler) ? $this->display_handler->display : NULL;
    $id = $this->storage
      ->id();
    if ($display) {
      $themes[] = $hook . '__' . $id . '__' . $display['id'];
      $themes[] = $hook . '__' . $display['id'];

      // Add theme suggestions for each single tag.
      foreach (Tags::explode($this->storage
        ->get('tag')) as $tag) {
        $themes[] = $hook . '__' . preg_replace('/[^a-z0-9]/', '_', strtolower($tag));
      }
      if ($display['id'] != $display['display_plugin']) {
        $themes[] = $hook . '__' . $id . '__' . $display['display_plugin'];
        $themes[] = $hook . '__' . $display['display_plugin'];
      }
    }
    $themes[] = $hook . '__' . $id;
    $themes[] = $hook;
    return $themes;
  }

  /**
   * Determines if this view has form elements.
   *
   * @return bool
   *   Returns TRUE if this view contains handlers with views form
   *   implementations, FALSE otherwise.
   */
  public function hasFormElements() {
    foreach ($this->field as $field) {
      if (property_exists($field, 'views_form_callback') || method_exists($field, 'viewsForm')) {
        return TRUE;
      }
    }
    $area_handlers = array_merge(array_values($this->header), array_values($this->footer));
    $empty = empty($this->result);
    foreach ($area_handlers as $area) {
      if (method_exists($area, 'viewsForm') && !$area
        ->viewsFormEmpty($empty)) {
        return TRUE;
      }
    }
    return FALSE;
  }

  /**
   * Gets dependencies for the view.
   *
   * @see \Drupal\views\Entity\View::calculateDependencies()
   * @see \Drupal\views\Entity\View::getDependencies()
   *
   * @return array
   *   An array of dependencies grouped by type (module, theme, entity).
   */
  public function getDependencies() {
    return $this->storage
      ->calculateDependencies()
      ->getDependencies();
  }

  /**
   * {@inheritdoc}
   */
  public function serialize() {
    return serialize([
      // Only serialize the storage entity ID.
      $this->storage
        ->id(),
      $this->current_display,
      $this->args,
      $this->current_page,
      $this->exposed_input,
      $this->exposed_raw_input,
      $this->exposed_data,
      $this->dom_id,
      $this->executed,
    ]);
  }

  /**
   * {@inheritdoc}
   */
  public function unserialize($serialized) {
    list($storage, $current_display, $args, $current_page, $exposed_input, $exposed_raw_input, $exposed_data, $dom_id, $executed) = unserialize($serialized);
    $this
      ->setRequest(\Drupal::request());
    $this->user = \Drupal::currentUser();
    $this->storage = \Drupal::entityManager()
      ->getStorage('view')
      ->load($storage);
    $this
      ->setDisplay($current_display);
    $this
      ->setArguments($args);
    $this
      ->setCurrentPage($current_page);
    $this
      ->setExposedInput($exposed_input);
    $this->exposed_data = $exposed_data;
    $this->exposed_raw_input = $exposed_raw_input;
    $this->dom_id = $dom_id;
    $this
      ->initHandlers();

    // If the display was previously executed, execute it now.
    if ($executed) {
      $this
        ->execute($this->current_display);
    }
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DependencySerializationTrait::$_serviceIds	protected	property	An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep	public	function		1
DependencySerializationTrait::__wakeup	public	function		2
ViewExecutable::$ajaxEnabled	protected	property	Whether this view uses AJAX.
ViewExecutable::$args	public	property	Any arguments that have been passed into the view.
ViewExecutable::$argument	public	property	Stores the argument handlers which are initialized on this view.
ViewExecutable::$attachment_after	public	property	Attachments to place after the view.
ViewExecutable::$attachment_before	public	property	Attachments to place before the view.
ViewExecutable::$base_database	public	property	Allow to override the used database which is used for this query.
ViewExecutable::$build_info	public	property	An array of build info.
ViewExecutable::$build_sort	public	property	Indicates if the sorts have been built.
ViewExecutable::$built	public	property	Whether or not the view has been built.
ViewExecutable::$current_display	public	property	Identifier of the current display.
ViewExecutable::$current_page	protected	property	The current page. If the view uses pagination.
ViewExecutable::$displayHandlers	public	property	The list of used displays of the view.
ViewExecutable::$display_handler	public	property	The current used display plugin.
ViewExecutable::$dom_id	public	property	A unique identifier which allows to update multiple views output via js.
ViewExecutable::$element	public	property	A render array container to store render related information.
ViewExecutable::$empty	public	property	Stores the area handlers for the empty text which are initialized on this view.
ViewExecutable::$executed	public	property	Whether the view has been executed/query has been run.
ViewExecutable::$exposed_data	public	property	All the form data from $form_state->getValues().
ViewExecutable::$exposed_input	protected	property	An array of input values from exposed forms.
ViewExecutable::$exposed_raw_input	public	property	Exposed widget input directly from the $form_state->getValues().
ViewExecutable::$exposed_widgets	public	property	The rendered output of the exposed form.
ViewExecutable::$feedIcons	public	property	Feed icons attached to the view.
ViewExecutable::$field	public	property	Stores the field handlers which are initialized on this view.
ViewExecutable::$filter	public	property	Stores the filter handlers which are initialized on this view.
ViewExecutable::$footer	public	property	Stores the area handlers for the footer which are initialized on this view.
ViewExecutable::$get_total_rows	public	property	Force the query to calculate the total number of results.
ViewExecutable::$header	public	property	Stores the area handlers for the header which are initialized on this view.
ViewExecutable::$inited	public	property	Does this view already have loaded it's handlers.
ViewExecutable::$is_attachment	public	property	Whether this view is an attachment to another view.
ViewExecutable::$items_per_page	protected	property	The number of items per page.
ViewExecutable::$many_to_one_tables	public	property	Stores the many-to-one tables for performance.
ViewExecutable::$offset	protected	property	The pager offset.
ViewExecutable::$old_view	public	property	Used to store views that were previously running if we recurse.
ViewExecutable::$override_path	public	property	Allow to override the path used for generated urls.
ViewExecutable::$override_url	public	property	Allow to override the url of the current view.
ViewExecutable::$pager	public	property	The used pager plugin used by the current executed view.
ViewExecutable::$parent_views	public	property	To avoid recursion in views embedded into areas.
ViewExecutable::$preview	public	property	If this view has been previewed.
ViewExecutable::$query	public	property	Where the $query object will reside.
ViewExecutable::$relationship	public	property	Stores the relationship handlers which are initialized on this view.
ViewExecutable::$request	protected	property	Stores the current request object.
ViewExecutable::$response	protected	property	Stores the current response object.
ViewExecutable::$result	public	property	Where the results of a query will go.
ViewExecutable::$routeProvider	protected	property	The route provider.
ViewExecutable::$rowPlugin	public	property	The current used row plugin, if the style plugin supports row plugins.
ViewExecutable::$row_index	public	property	Stores the current active row while rendering.
ViewExecutable::$showAdminLinks	protected	property	Should the admin links be shown on the rendered view.
ViewExecutable::$sort	public	property	Stores the sort handlers which are initialized on this view.
ViewExecutable::$storage	public	property	The config entity in which the view is stored.
ViewExecutable::$style_plugin	public	property	The current used style plugin.
ViewExecutable::$total_rows	public	property	The total number of rows returned from the query.
ViewExecutable::$user	protected	property	The current user.
ViewExecutable::$viewsData	protected	property	The views data.
ViewExecutable::access	public	function	Determine if the given user has access to the view. Note that this sets the display handler if it hasn't been.
ViewExecutable::addCacheContext	public	function	Expands the list of used cache contexts for the view.
ViewExecutable::addHandler	public	function	Adds an instance of a handler to the view.
ViewExecutable::ajaxEnabled	public	function	Whether or not AJAX should be used.
ViewExecutable::attachDisplays	public	function	Run attachment displays for the view.
ViewExecutable::build	public	function	Build the query for the view.
ViewExecutable::buildRenderable	public	function	Builds the render array outline for the given display.
ViewExecutable::buildThemeFunctions	public	function	Provide a full array of possible theme functions to try for a given hook.
ViewExecutable::buildTitle	public	function	Force the view to build a title.
ViewExecutable::chooseDisplay	public	function	Get the first display that is accessible to the user.
ViewExecutable::createDuplicate	public	function	Creates a duplicate ViewExecutable object.
ViewExecutable::destroy	public	function	Unset references so that a $view object may be properly garbage collected.
ViewExecutable::execute	public	function	Execute the view's query.
ViewExecutable::executeDisplay	public	function	Execute the given display, with the given arguments. To be called externally by whatever mechanism invokes the view, such as a page callback, hook_block, etc.
ViewExecutable::generateHandlerId	public static	function	Generates a unique ID for an handler instance.
ViewExecutable::getBaseTables	public	function	Create a list of base tables eligible for this view. Used primarily for the UI. Display must be already initialized.
ViewExecutable::getCacheTags	public	function	Gets the cache tags associated with the executed view.
ViewExecutable::getCurrentPage	public	function	Get the current page from the pager.
ViewExecutable::getDependencies	public	function	Gets dependencies for the view.
ViewExecutable::getDisplay	public	function	Gets the current display plugin.
ViewExecutable::getExposedInput	public	function	Figure out what the exposed input for this view is.
ViewExecutable::getHandler	public	function	Gets the configuration of a handler instance on a given display.
ViewExecutable::getHandlers	public	function	Gets an array of handler instances for the current display.
ViewExecutable::getHandlerTypes	public static	function	Provide a list of views handler types used in a view, with some information about them.
ViewExecutable::getItemsPerPage	public	function	Get the items per page from the pager.
ViewExecutable::getOffset	public	function	Get the pager offset from the pager.
ViewExecutable::getPager	public	function	Get the current pager plugin.
ViewExecutable::getPath	public	function	Get the base path used for this view.
ViewExecutable::getPluginTypes	public static	function	Returns the valid types of plugins that can be used.
ViewExecutable::getQuery	public	function	Gets the current query plugin.
ViewExecutable::getRequest	public	function	Gets the request object.
ViewExecutable::getResponse	public	function	Gets the response object used by the view.
ViewExecutable::getShowAdminLinks	public	function	Returns whether admin links should be rendered on the view.
ViewExecutable::getStyle	public	function	Gets the current style plugin.
ViewExecutable::getTitle	public	function	Get the view's current title. This can change depending upon how it was built.
ViewExecutable::getUrl	public	function	Get the URL for the current view.
ViewExecutable::getUrlInfo	public	function	Gets the Url object associated with the display handler.
ViewExecutable::getUser	public	function	Gets the current user.
ViewExecutable::hasFormElements	public	function	Determines if this view has form elements.
ViewExecutable::hasUrl	public	function	Determines whether you can link to the view or a particular display.
ViewExecutable::id	public	function	Returns the identifier.
ViewExecutable::initDisplay	public	function	Set the display for this view and initialize the display handler.
ViewExecutable::initHandlers	public	function	Acquire and attach all of the handlers.
ViewExecutable::initPager	public	function	Initialize the pager
ViewExecutable::initQuery	public	function	Do some common building initialization.
ViewExecutable::initStyle	public	function	Find and initialize the style plugin.
ViewExecutable::mergeDefaults	public	function	Merges all plugin default values for each display.
ViewExecutable::newDisplay	public	function	Creates a new display and a display handler instance for it.
ViewExecutable::postExecute	public	function	Unset the current view, mostly.
ViewExecutable::preExecute	public	function	Run attachments and let the display do what it needs to do prior to running.
ViewExecutable::preview	public	function	Preview the given display, with the given arguments.
ViewExecutable::removeHandler	public	function	Removes configuration for a handler instance on a given display.
ViewExecutable::render	public	function	Render this view for a certain display.
ViewExecutable::renderPager	public	function	Render the pager, if necessary.
ViewExecutable::save	public	function	Saves the view.
ViewExecutable::serialize	public	function
ViewExecutable::setAjaxEnabled	public	function	Sets whether or not AJAX should be used.
ViewExecutable::setArguments	public	function	Set the arguments that come to this view. Usually from the URL but possibly from elsewhere.
ViewExecutable::setCurrentPage	public	function	Change/Set the current page for the pager.
ViewExecutable::setDisplay	public	function	Sets the current display.
ViewExecutable::setExposedInput	public	function	Set the exposed filters input to an array. If unset they will be taken from \Drupal::request()->query when the time comes.
ViewExecutable::setHandler	public	function	Sets the configuration of a handler instance on a given display.
ViewExecutable::setHandlerOption	public	function	Sets an option on a handler instance.
ViewExecutable::setItemsPerPage	public	function	Set the items per page on the pager.
ViewExecutable::setOffset	public	function	Set the offset on the pager.
ViewExecutable::setRequest	public	function	Sets the request object.
ViewExecutable::setResponse	public	function	Sets the used response object of the view.
ViewExecutable::setShowAdminLinks	public	function	Enables admin links on the rendered view.
ViewExecutable::setTitle	public	function	Override the view's current title.
ViewExecutable::unserialize	public	function
ViewExecutable::usePager	public	function	Determine if the pager actually uses a pager.
ViewExecutable::validate	public	function	Makes sure the view is completely valid.
ViewExecutable::_build	public	function	Internal method to build an individual set of handlers.
ViewExecutable::_buildArguments	protected	function	Build all the arguments.
ViewExecutable::_initHandler	protected	function	Attach all of the handlers for each type.
ViewExecutable::_postExecute	protected	function	Run the postExecute() on all active handlers.
ViewExecutable::_preQuery	protected	function	Run the preQuery() on all active handlers.
ViewExecutable::__construct	public	function	Constructs a new ViewExecutable object.