function view::build

Build the query for the view.

File

modules/views/includes/view.inc, line 955

Provides the view object type and associated methods.

Class

view

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.

Code

function build($display_id = NULL) {
  if (!empty($this->built)) {
    return;
  }

  if (empty($this->current_display) || $display_id) {
    if (!$this->set_display($display_id)) {
      return FALSE;
    }
  }

  // Let modules modify the view just prior to building it.
  foreach (module_implements('views_pre_build') as $module) {
    $function = $module . '_views_pre_build';
    $function($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->init_query();

  // 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->init_handlers();

  // Let the handlers interact with each other if they really want.
  $this->_pre_query();

  if ($this->display_handler->uses_exposed()) {
    $exposed_form = $this->display_handler->get_plugin('exposed_form');
    // (1) Record the errors before rendering the exposed form widgets.
    $errors_before = form_set_error();
    $this->exposed_widgets = $exposed_form->render_exposed_form();
    // (2) Record the errors after rendering the exposed form widgets.
    $errors_after = form_set_error();
    // Find out if the validation of any of the elements in the exposed form
    // has failed by comparing (1) and (2) above. Don't mess with the view
    // otherwise.
    $exposed_errors = count($errors_after) > count($errors_before);
    if ($exposed_errors || !empty($this->build_info['abort'])) {
      $this->built = TRUE;
      // Don't execute the query, 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 = $this->display_handler->get_option('filter_groups');
    if ($filter_groups) {
      $this->query->set_group_operator($filter_groups['operator']);
      foreach ($filter_groups['groups'] as $id => $operator) {
        $this->query->set_where_group($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->_build_arguments()) {
    $this->build_time = microtime(TRUE) - $start;
    $this->attach_displays();
    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->init_style()) {
    $this->build_info['fail'] = TRUE;
    return FALSE;
  }

  if ($this->style_plugin->uses_fields()) {
    $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->build_sort()) {
      $this->_build('sort');
    }
    // allow the plugin to build second sorts as well.
    $this->style_plugin->build_sort_post();
  }

  // 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->use_group_by());

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

  // Allow exposed form to affect the query:
  if (isset($exposed_form)) {
    $exposed_form->query();
  }

  if (config_get('views.settings', 'sql_signature')) {
    $this->query->add_signature($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->attach_displays();

  // Let modules modify the view just after building it.
  foreach (module_implements('views_post_build') as $module) {
    $function = $module . '_views_post_build';
    $function($this);
  }

  return TRUE;
}