abstract class StylePluginBase

Base class to define a style plugin handler.

Hierarchy

Expanded class hierarchy of StylePluginBase

Related topics

2 files declare their use of StylePluginBase
DefaultSummary.php in drupal/core/modules/views/lib/Drupal/views/Plugin/views/style/DefaultSummary.php
Definition of Drupal\views\Plugin\views\style\StyleSummaryPluginBase.
StyleTest.php in drupal/core/modules/views/tests/views_test_data/lib/Drupal/views_test_data/Plugin/views/style/StyleTest.php
Definition of Drupal\views_test_data\Plugin\views\style\StyleTest.

File

drupal/core/modules/views/lib/Drupal/views/Plugin/views/style/StylePluginBase.php, line 31
Definition of Drupal\views\Plugin\views\style\StylePluginBase.

Namespace

Drupal\views\Plugin\views\style
View source
abstract class StylePluginBase extends PluginBase {

  /**
   * Overrides Drupal\views\Plugin\Plugin::$usesOptions.
   */
  protected $usesOptions = TRUE;

  /**
   * Store all available tokens row rows.
   */
  var $row_tokens = array();

  /**
   * Contains the row plugin, if it's initialized
   * and the style itself supports it.
   *
   * @var views_plugin_row
   */
  var $row_plugin;

  /**
   * Does the style plugin allows to use style plugins.
   *
   * @var bool
   */
  protected $usesRowPlugin = FALSE;

  /**
   * Does the style plugin support custom css class for the rows.
   *
   * @var bool
   */
  protected $usesRowClass = FALSE;

  /**
   * Does the style plugin support grouping of rows.
   *
   * @var bool
   */
  protected $usesGrouping = TRUE;

  /**
   * Does the style plugin for itself support to add fields to it's output.
   *
   * This option only makes sense on style plugins without row plugins, like
   * for example table.
   *
   * @var bool
   */
  protected $usesFields = FALSE;

  /**
   * Initialize a style plugin.
   *
   * @param $view
   * @param $display
   * @param $options
   *   The style options might come externally as the style can be sourced
   *   from at least two locations. If it's not included, look on the display.
   */
  public function init(ViewExecutable $view, &$display, $options = NULL) {
    $this
      ->setOptionDefaults($this->options, $this
      ->defineOptions());
    $this->view =& $view;
    $this->displayHandler =& $display;
    $this
      ->unpackOptions($this->options, $options);
    if ($this
      ->usesRowPlugin() && $display
      ->getOption('row')) {
      $this->row_plugin = $display
        ->getPlugin('row');
    }
    $this->options += array(
      'grouping' => array(),
    );
  }
  public function destroy() {
    parent::destroy();
    if (isset($this->row_plugin)) {
      $this->row_plugin
        ->destroy();
    }
  }

  /**
   * Returns the usesRowPlugin property.
   *
   * @return bool
   */
  function usesRowPlugin() {
    return $this->usesRowPlugin;
  }

  /**
   * Returns the usesRowClass property.
   *
   * @return bool
   */
  function usesRowClass() {
    return $this->usesRowClass;
  }

  /**
   * Returns the usesGrouping property.
   *
   * @return bool
   */
  function usesGrouping() {
    return $this->usesGrouping;
  }

  /**
   * Return TRUE if this style also uses fields.
   *
   * @return bool
   */
  function usesFields() {

    // If we use a row plugin, ask the row plugin. Chances are, we don't
    // care, it does.
    $row_uses_fields = FALSE;
    if ($this
      ->usesRowPlugin() && !empty($this->row_plugin)) {
      $row_uses_fields = $this->row_plugin
        ->usesFields();
    }

    // Otherwise, check the definition or the option.
    return $row_uses_fields || $this->usesFields || !empty($this->options['uses_fields']);
  }

  /**
   * Return TRUE if this style uses tokens.
   *
   * Used to ensure we don't fetch tokens when not needed for performance.
   */
  function uses_tokens() {
    if ($this
      ->usesRowClass()) {
      $class = $this->options['row_class'];
      if (strpos($class, '[') !== FALSE || strpos($class, '!') !== FALSE || strpos($class, '%') !== FALSE) {
        return TRUE;
      }
    }
  }

  /**
   * Return the token replaced row class for the specified row.
   */
  function get_row_class($row_index) {
    if ($this
      ->usesRowClass()) {
      $class = $this->options['row_class'];
      if ($this
        ->usesFields() && $this->view->field) {
        $class = strip_tags($this
          ->tokenize_value($class, $row_index));
      }
      $classes = explode(' ', $class);
      foreach ($classes as &$class) {
        $class = drupal_clean_css_identifier($class);
      }
      return implode(' ', $classes);
    }
  }

  /**
   * Take a value and apply token replacement logic to it.
   */
  function tokenize_value($value, $row_index) {
    if (strpos($value, '[') !== FALSE || strpos($value, '!') !== FALSE || strpos($value, '%') !== FALSE) {
      $fake_item = array(
        'alter_text' => TRUE,
        'text' => $value,
      );

      // Row tokens might be empty, for example for node row style.
      $tokens = isset($this->row_tokens[$row_index]) ? $this->row_tokens[$row_index] : array();
      if (!empty($this->view->build_info['substitutions'])) {
        $tokens += $this->view->build_info['substitutions'];
      }
      if ($tokens) {
        $value = strtr($value, $tokens);
      }
    }
    return $value;
  }

  /**
   * Should the output of the style plugin be rendered even if it's a empty view.
   */
  function even_empty() {
    return !empty($this->definition['even empty']);
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['grouping'] = array(
      'default' => array(),
    );
    if ($this
      ->usesRowClass()) {
      $options['row_class'] = array(
        'default' => '',
      );
      $options['default_row_class'] = array(
        'default' => TRUE,
        'bool' => TRUE,
      );
      $options['row_class_special'] = array(
        'default' => TRUE,
        'bool' => TRUE,
      );
    }
    $options['uses_fields'] = array(
      'default' => FALSE,
      'bool' => TRUE,
    );
    return $options;
  }
  public function buildOptionsForm(&$form, &$form_state) {
    parent::buildOptionsForm($form, $form_state);

    // Only fields-based views can handle grouping.  Style plugins can also exclude
    // themselves from being groupable by setting their "usesGrouping" property
    // to FALSE.
    // @TODO: Document "usesGrouping" in docs.php when docs.php is written.
    if ($this
      ->usesFields() && $this
      ->usesGrouping()) {
      $options = array(
        '' => t('- None -'),
      );
      $field_labels = $this->displayHandler
        ->getFieldLabels(TRUE);
      $options += $field_labels;

      // If there are no fields, we can't group on them.
      if (count($options) > 1) {

        // This is for backward compability, when there was just a single select form.
        if (is_string($this->options['grouping'])) {
          $grouping = $this->options['grouping'];
          $this->options['grouping'] = array();
          $this->options['grouping'][0]['field'] = $grouping;
        }
        if (isset($this->options['group_rendered']) && is_string($this->options['group_rendered'])) {
          $this->options['grouping'][0]['rendered'] = $this->options['group_rendered'];
          unset($this->options['group_rendered']);
        }
        $c = count($this->options['grouping']);

        // Add a form for every grouping, plus one.
        for ($i = 0; $i <= $c; $i++) {
          $grouping = !empty($this->options['grouping'][$i]) ? $this->options['grouping'][$i] : array();
          $grouping += array(
            'field' => '',
            'rendered' => TRUE,
            'rendered_strip' => FALSE,
          );
          $form['grouping'][$i]['field'] = array(
            '#type' => 'select',
            '#title' => t('Grouping field Nr.@number', array(
              '@number' => $i + 1,
            )),
            '#options' => $options,
            '#default_value' => $grouping['field'],
            '#description' => t('You may optionally specify a field by which to group the records. Leave blank to not group.'),
          );
          $form['grouping'][$i]['rendered'] = array(
            '#type' => 'checkbox',
            '#title' => t('Use rendered output to group rows'),
            '#default_value' => $grouping['rendered'],
            '#description' => t('If enabled the rendered output of the grouping field is used to group the rows.'),
            '#states' => array(
              'invisible' => array(
                ':input[name="style_options[grouping][' . $i . '][field]"]' => array(
                  'value' => '',
                ),
              ),
            ),
          );
          $form['grouping'][$i]['rendered_strip'] = array(
            '#type' => 'checkbox',
            '#title' => t('Remove tags from rendered output'),
            '#default_value' => $grouping['rendered_strip'],
            '#states' => array(
              'invisible' => array(
                ':input[name="style_options[grouping][' . $i . '][field]"]' => array(
                  'value' => '',
                ),
              ),
            ),
          );
        }
      }
    }
    if ($this
      ->usesRowClass()) {
      $form['row_class'] = array(
        '#title' => t('Row class'),
        '#description' => t('The class to provide on each row.'),
        '#type' => 'textfield',
        '#default_value' => $this->options['row_class'],
      );
      if ($this
        ->usesFields()) {
        $form['row_class']['#description'] .= ' ' . t('You may use field tokens from as per the "Replacement patterns" used in "Rewrite the output of this field" for all fields.');
      }
      $form['default_row_class'] = array(
        '#title' => t('Add views row classes'),
        '#description' => t('Add the default row classes like views-row-1 to the output. You can use this to quickly reduce the amount of markup the view provides by default, at the cost of making it more difficult to apply CSS.'),
        '#type' => 'checkbox',
        '#default_value' => $this->options['default_row_class'],
      );
      $form['row_class_special'] = array(
        '#title' => t('Add striping (odd/even), first/last row classes'),
        '#description' => t('Add css classes to the first and last line, as well as odd/even classes for striping.'),
        '#type' => 'checkbox',
        '#default_value' => $this->options['row_class_special'],
      );
    }
    if (!$this
      ->usesFields() || !empty($this->options['uses_fields'])) {
      $form['uses_fields'] = array(
        '#type' => 'checkbox',
        '#title' => t('Force using fields'),
        '#description' => t('If neither the row nor the style plugin supports fields, this field allows to enable them, so you can for example use groupby.'),
        '#default_value' => $this->options['uses_fields'],
      );
    }
  }
  public function validateOptionsForm(&$form, &$form_state) {

    // Don't run validation on style plugins without the grouping setting.
    if (isset($form_state['values']['style_options']['grouping'])) {

      // Don't save grouping if no field is specified.
      foreach ($form_state['values']['style_options']['grouping'] as $index => $grouping) {
        if (empty($grouping['field'])) {
          unset($form_state['values']['style_options']['grouping'][$index]);
        }
      }
    }
  }

  /**
   * Provide a form in the views wizard if this style is selected.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param array $form_state
   *   An associative array containing the current state of the form.
   * @param string $type
   *    The display type, either block or page.
   */
  function wizard_form(&$form, &$form_state, $type) {
  }

  /**
   * Alter the options of a display before they are added to the view.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param array $form_state
   *   An associative array containing the current state of the form.
   * @param Drupal\views\Plugin\views\wizard\WizardInterface $wizard
   *   The current used wizard.
   * @param array $display_options
   *   The options which will be used on the view. The style plugin should
   *   alter this to its own needs.
   * @param string $display_type
   *   The display type, either block or page.
   */
  function wizard_submit(&$form, &$form_state, WizardInterface $wizard, &$display_options, $display_type) {
  }

  /**
   * Called by the view builder to see if this style handler wants to
   * interfere with the sorts. If so it should build; if it returns
   * any non-TRUE value, normal sorting will NOT be added to the query.
   */
  function build_sort() {
    return TRUE;
  }

  /**
   * Called by the view builder to let the style build a second set of
   * sorts that will come after any other sorts in the view.
   */
  function build_sort_post() {
  }

  /**
   * Allow the style to do stuff before each row is rendered.
   *
   * @param $result
   *   The full array of results from the query.
   */
  function pre_render($result) {
    if (!empty($this->row_plugin)) {
      $this->row_plugin
        ->pre_render($result);
    }
  }

  /**
   * Render the display in this style.
   */
  function render() {
    if ($this
      ->usesRowPlugin() && empty($this->row_plugin)) {
      debug('Drupal\\views\\Plugin\\views\\style\\StylePluginBase: Missing row plugin');
      return;
    }

    // Group the rows according to the grouping instructions, if specified.
    $sets = $this
      ->render_grouping($this->view->result, $this->options['grouping'], TRUE);
    return $this
      ->render_grouping_sets($sets);
  }

  /**
   * Render the grouping sets.
   *
   * Plugins may override this method if they wish some other way of handling
   * grouping.
   *
   * @param $sets
   *   Array containing the grouping sets to render.
   * @param $level
   *   Integer indicating the hierarchical level of the grouping.
   *
   * @return string
   *   Rendered output of given grouping sets.
   */
  function render_grouping_sets($sets, $level = 0) {
    $output = array();
    $theme_functions = views_theme_functions('views_view_grouping', $this->view, $this->view->display_handler->display);
    foreach ($sets as $set) {
      $row = reset($set['rows']);

      // Render as a grouping set.
      if (is_array($row) && isset($row['group'])) {
        $output[] = array(
          '#theme' => $theme_functions,
          '#view' => $this->view,
          '#grouping' => $this->options['grouping'][$level],
          '#grouping_level' => $level,
          '#rows' => $set['rows'],
          '#title' => $set['group'],
        );
      }
      else {
        if ($this
          ->usesRowPlugin()) {
          foreach ($set['rows'] as $index => $row) {
            $this->view->row_index = $index;
            $render = $this->row_plugin
              ->render($row);

            // Row render arrays cannot be contained by style render arrays.
            $set['rows'][$index] = drupal_render($render);
          }
        }
        $output[] = array(
          '#theme' => $this
            ->themeFunctions(),
          '#view' => $this->view,
          '#options' => $this->options,
          '#grouping_level' => $level,
          '#rows' => $set['rows'],
          '#title' => $set['group'],
        );
      }
    }
    unset($this->view->row_index);
    return $output;
  }

  /**
   * Group records as needed for rendering.
   *
   * @param $records
   *   An array of records from the view to group.
   * @param $groupings
   *   An array of grouping instructions on which fields to group. If empty, the
   *   result set will be given a single group with an empty string as a label.
   * @param $group_rendered
   *   Boolean value whether to use the rendered or the raw field value for
   *   grouping. If set to NULL the return is structured as before
   *   Views 7.x-3.0-rc2. After Views 7.x-3.0 this boolean is only used if
   *   $groupings is an old-style string or if the rendered option is missing
   *   for a grouping instruction.
   * @return
   *   The grouped record set.
   *   A nested set structure is generated if multiple grouping fields are used.
   *
   *   @code
   *   array(
   *     'grouping_field_1:grouping_1' => array(
   *       'group' => 'grouping_field_1:content_1',
   *       'rows' => array(
   *         'grouping_field_2:grouping_a' => array(
   *           'group' => 'grouping_field_2:content_a',
   *           'rows' => array(
   *             $row_index_1 => $row_1,
   *             $row_index_2 => $row_2,
   *             // ...
   *           )
   *         ),
   *       ),
   *     ),
   *     'grouping_field_1:grouping_2' => array(
   *       // ...
   *     ),
   *   )
   *   @endcode
   */
  function render_grouping($records, $groupings = array(), $group_rendered = NULL) {

    // This is for backward compability, when $groupings was a string containing
    // the ID of a single field.
    if (is_string($groupings)) {
      $rendered = $group_rendered === NULL ? TRUE : $group_rendered;
      $groupings = array(
        array(
          'field' => $groupings,
          'rendered' => $rendered,
        ),
      );
    }

    // Make sure fields are rendered
    $this
      ->render_fields($this->view->result);
    $sets = array();
    if ($groupings) {
      foreach ($records as $index => $row) {

        // Iterate through configured grouping fields to determine the
        // hierarchically positioned set where the current row belongs to.
        // While iterating, parent groups, that do not exist yet, are added.
        $set =& $sets;
        foreach ($groupings as $info) {
          $field = $info['field'];
          $rendered = isset($info['rendered']) ? $info['rendered'] : $group_rendered;
          $rendered_strip = isset($info['rendered_strip']) ? $info['rendered_strip'] : FALSE;
          $grouping = '';
          $group_content = '';

          // Group on the rendered version of the field, not the raw.  That way,
          // we can control any special formatting of the grouping field through
          // the admin or theme layer or anywhere else we'd like.
          if (isset($this->view->field[$field])) {
            $group_content = $this
              ->get_field($index, $field);
            if ($this->view->field[$field]->options['label']) {
              $group_content = $this->view->field[$field]->options['label'] . ': ' . $group_content;
            }
            if ($rendered) {
              $grouping = $group_content;
              if ($rendered_strip) {
                $group_content = $grouping = strip_tags(htmlspecialchars_decode($group_content));
              }
            }
            else {
              $grouping = $this
                ->get_field_value($index, $field);

              // Not all field handlers return a scalar value,
              // e.g. views_handler_field_field.
              if (!is_scalar($grouping)) {
                $grouping = md5(serialize($grouping));
              }
            }
          }

          // Create the group if it does not exist yet.
          if (empty($set[$grouping])) {
            $set[$grouping]['group'] = $group_content;
            $set[$grouping]['rows'] = array();
          }

          // Move the set reference into the row set of the group we just determined.
          $set =& $set[$grouping]['rows'];
        }

        // Add the row to the hierarchically positioned row set we just determined.
        $set[$index] = $row;
      }
    }
    else {

      // Create a single group with an empty grouping field.
      $sets[''] = array(
        'group' => '',
        'rows' => $records,
      );
    }

    // If this parameter isn't explicitely set modify the output to be fully
    // backward compatible to code before Views 7.x-3.0-rc2.
    // @TODO Remove this as soon as possible e.g. October 2020
    if ($group_rendered === NULL) {
      $old_style_sets = array();
      foreach ($sets as $group) {
        $old_style_sets[$group['group']] = $group['rows'];
      }
      $sets = $old_style_sets;
    }
    return $sets;
  }

  /**
   * Render all of the fields for a given style and store them on the object.
   *
   * @param $result
   *   The result array from $view->result
   */
  function render_fields($result) {
    if (!$this
      ->usesFields()) {
      return;
    }
    if (!isset($this->rendered_fields)) {
      $this->rendered_fields = array();
      $this->view->row_index = 0;
      $keys = array_keys($this->view->field);

      // If all fields have a field::access FALSE there might be no fields, so
      // there is no reason to execute this code.
      if (!empty($keys)) {
        foreach ($result as $count => $row) {
          $this->view->row_index = $count;
          foreach ($keys as $id) {
            $this->rendered_fields[$count][$id] = $this->view->field[$id]
              ->theme($row);
          }
          $this->row_tokens[$count] = $this->view->field[$id]
            ->get_render_tokens(array());
        }
      }
      unset($this->view->row_index);
    }
    return $this->rendered_fields;
  }

  /**
   * Get a rendered field.
   *
   * @param $index
   *   The index count of the row.
   * @param $field
   *    The id of the field.
   */
  function get_field($index, $field) {
    if (!isset($this->rendered_fields)) {
      $this
        ->render_fields($this->view->result);
    }
    if (isset($this->rendered_fields[$index][$field])) {
      return $this->rendered_fields[$index][$field];
    }
  }

  /**
   * Get the raw field value.
   *
   * @param $index
   *   The index count of the row.
   * @param $field
   *    The id of the field.
   */
  function get_field_value($index, $field) {
    $this->view->row_index = $index;
    $value = $this->view->field[$field]
      ->get_value($this->view->result[$index]);
    unset($this->view->row_index);
    return $value;
  }
  public function validate() {
    $errors = parent::validate();
    if ($this
      ->usesRowPlugin()) {
      $plugin = $this->displayHandler
        ->getPlugin('row');
      if (empty($plugin)) {
        $errors[] = t('Style @style requires a row style but the row plugin is invalid.', array(
          '@style' => $this->definition['title'],
        ));
      }
      else {
        $result = $plugin
          ->validate();
        if (!empty($result) && is_array($result)) {
          $errors = array_merge($errors, $result);
        }
      }
    }
    return $errors;
  }
  public function query() {
    parent::query();
    if (isset($this->row_plugin)) {
      $this->row_plugin
        ->query();
    }
  }

}

Members

Namesort descending Modifiers Type Description Overrides
PluginBase::$configuration protected property Configuration information passed into the plugin. 1
PluginBase::$definition public property Plugins's definition
PluginBase::$discovery protected property The discovery object.
PluginBase::$displayHandler public property The display object this plugin is for.
PluginBase::$options public property Options for this plugin will be held here.
PluginBase::$plugin_id protected property The plugin_id.
PluginBase::$view public property The top object of a view. 1
PluginBase::additionalThemeFunctions public function Provide a list of additional theme functions for the theme information page
PluginBase::getAvailableGlobalTokens public function Returns an array of available token replacements.
PluginBase::getDefinition public function Implements Drupal\Component\Plugin\PluginInterface::getDefinition(). Overrides PluginInspectionInterface::getDefinition
PluginBase::getPluginId public function Implements Drupal\Component\Plugin\PluginInterface::getPluginId(). Overrides PluginInspectionInterface::getPluginId
PluginBase::globalTokenForm public function Adds elements for available core tokens to a form.
PluginBase::globalTokenReplace public function Returns a string with any core tokens replaced.
PluginBase::pluginTitle public function Return the human readable name of the display.
PluginBase::setOptionDefaults protected function
PluginBase::submitOptionsForm public function Handle any special handling on the validate form. 10
PluginBase::summaryTitle public function Returns the summary of the settings in the display. 6
PluginBase::themeFunctions public function Provide a full list of possible theme templates used by this style. 1
PluginBase::unpackOptions public function Unpack options over our existing defaults, drilling down into arrays so that defaults don't get totally blown away.
PluginBase::usesOptions public function Returns the usesOptions property. 8
PluginBase::__construct public function Constructs a Plugin object. Overrides PluginBase::__construct
StylePluginBase::$row_plugin property Contains the row plugin, if it's initialized and the style itself supports it.
StylePluginBase::$row_tokens property Store all available tokens row rows.
StylePluginBase::$usesFields protected property Does the style plugin for itself support to add fields to it's output. 2
StylePluginBase::$usesGrouping protected property Does the style plugin support grouping of rows. 1
StylePluginBase::$usesOptions protected property Overrides Drupal\views\Plugin\Plugin::$usesOptions. Overrides PluginBase::$usesOptions
StylePluginBase::$usesRowClass protected property Does the style plugin support custom css class for the rows. 4
StylePluginBase::$usesRowPlugin protected property Does the style plugin allows to use style plugins. 6
StylePluginBase::buildOptionsForm public function Provide a form to edit options for this plugin. Overrides PluginBase::buildOptionsForm 7
StylePluginBase::build_sort function Called by the view builder to see if this style handler wants to interfere with the sorts. If so it should build; if it returns any non-TRUE value, normal sorting will NOT be added to the query. 1
StylePluginBase::build_sort_post function Called by the view builder to let the style build a second set of sorts that will come after any other sorts in the view. 1
StylePluginBase::defineOptions protected function Information about options for all kinds of purposes will be held here. @code 'option_name' => array( Overrides PluginBase::defineOptions 7
StylePluginBase::destroy public function Clears a plugin. Overrides PluginBase::destroy
StylePluginBase::even_empty function Should the output of the style plugin be rendered even if it's a empty view. 1
StylePluginBase::get_field function Get a rendered field.
StylePluginBase::get_field_value function Get the raw field value.
StylePluginBase::get_row_class function Return the token replaced row class for the specified row.
StylePluginBase::init public function Initialize a style plugin.
StylePluginBase::pre_render function Allow the style to do stuff before each row is rendered.
StylePluginBase::query public function Add anything to the query that we might need to. Overrides PluginBase::query 1
StylePluginBase::render function Render the display in this style. 4
StylePluginBase::render_fields function Render all of the fields for a given style and store them on the object.
StylePluginBase::render_grouping function Group records as needed for rendering.
StylePluginBase::render_grouping_sets function Render the grouping sets.
StylePluginBase::tokenize_value function Take a value and apply token replacement logic to it.
StylePluginBase::usesFields function Return TRUE if this style also uses fields. 2
StylePluginBase::usesGrouping function Returns the usesGrouping property. 1
StylePluginBase::usesRowClass function Returns the usesRowClass property. 4
StylePluginBase::usesRowPlugin function Returns the usesRowPlugin property. 6
StylePluginBase::uses_tokens function Return TRUE if this style uses tokens.
StylePluginBase::validate public function Validate that the plugin is correct and can be saved. Overrides PluginBase::validate
StylePluginBase::validateOptionsForm public function Validate the options form. Overrides PluginBase::validateOptionsForm
StylePluginBase::wizard_form function Provide a form in the views wizard if this style is selected.
StylePluginBase::wizard_submit function Alter the options of a display before they are added to the view. 1