public function ViewExecutable::build

Builds the query for the view.

Parameters

string $display_id: The display ID of the view.

Return value

bool|null TRUE if the view build process was successful, FALSE if setting the display fails or NULL if the view has been built already.

File

core/modules/views/src/ViewExecutable.php, line 1196

Class

ViewExecutable

Represents a view as a whole.

Namespace

Code

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', [
    $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 = [
    'query' => '',
    'count_query' => '',
    'query_args' => [],
  ];
  $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()) {

    /** @var \Drupal\views\Plugin\views\exposed_form\ExposedFormPluginInterface $exposed_form */
    $exposed_form = $this->display_handler
      ->getPlugin('exposed_form');
    $this->exposed_widgets = $exposed_form
      ->renderExposedForm();
    if (!empty($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', [
    $this,
  ]);
  return TRUE;
}