public function ViewExecutable::render in Drupal 8

Same name and namespace in other branches

1. 9 core/modules/views/src/ViewExecutable.php \Drupal\views\ViewExecutable::render()

Renders this view for a certain display.

Note: You should better use just the preview function if you want to render a view.

Parameters

string $display_id: The machine name of the display, which should be rendered.

Return value

array|null A renderable array containing the view output or NULL if the build process failed.

File

core/modules/views/src/ViewExecutable.php, line 1453

Class

ViewExecutable

Represents a view as a whole.

Namespace

Drupal\views

Code

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;
  }

  /** @var \Drupal\views\Plugin\views\exposed_form\ExposedFormPluginInterface $exposed_form */
  $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
    ->getBaseThemeExtensions());
  $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 = [
    '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', [
    $this,
  ]);

  // Let the themes play too, because prerender 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', [
    $this,
    &$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;
}