Chris@0: <?php
Chris@0: 
Chris@0: /**
Chris@0:  * @file
Chris@0:  * Adds contextual links to perform actions related to elements on a page.
Chris@0:  */
Chris@0: 
Chris@18: use Drupal\Core\Url;
Chris@0: use Drupal\Component\Serialization\Json;
Chris@0: use Drupal\Component\Utility\UrlHelper;
Chris@0: use Drupal\Core\Language\LanguageInterface;
Chris@0: use Drupal\Core\Routing\RouteMatchInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Implements hook_toolbar().
Chris@0:  */
Chris@0: function contextual_toolbar() {
Chris@0:   $items = [];
Chris@0:   $items['contextual'] = [
Chris@0:     '#cache' => [
Chris@0:       'contexts' => [
Chris@0:         'user.permissions',
Chris@0:       ],
Chris@0:     ],
Chris@0:   ];
Chris@0: 
Chris@0:   if (!\Drupal::currentUser()->hasPermission('access contextual links')) {
Chris@0:     return $items;
Chris@0:   }
Chris@0: 
Chris@0:   $items['contextual'] += [
Chris@0:     '#type' => 'toolbar_item',
Chris@0:     'tab' => [
Chris@0:       '#type' => 'html_tag',
Chris@0:       '#tag' => 'button',
Chris@0:       '#value' => t('Edit'),
Chris@0:       '#attributes' => [
Chris@0:         'class' => ['toolbar-icon', 'toolbar-icon-edit'],
Chris@0:         'aria-pressed' => 'false',
Chris@0:         'type' => 'button',
Chris@0:       ],
Chris@0:     ],
Chris@0:     '#wrapper_attributes' => [
Chris@0:       'class' => ['hidden', 'contextual-toolbar-tab'],
Chris@0:     ],
Chris@0:     '#attached' => [
Chris@0:       'library' => [
Chris@0:         'contextual/drupal.contextual-toolbar',
Chris@0:       ],
Chris@0:     ],
Chris@0:   ];
Chris@0: 
Chris@0:   return $items;
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * Implements hook_page_attachments().
Chris@0:  *
Chris@0:  * Adds the drupal.contextual-links library to the page for any user who has the
Chris@0:  * 'access contextual links' permission.
Chris@0:  *
Chris@0:  * @see contextual_preprocess()
Chris@0:  */
Chris@0: function contextual_page_attachments(array &$page) {
Chris@0:   if (!\Drupal::currentUser()->hasPermission('access contextual links')) {
Chris@0:     return;
Chris@0:   }
Chris@0: 
Chris@0:   $page['#attached']['library'][] = 'contextual/drupal.contextual-links';
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * Implements hook_help().
Chris@0:  */
Chris@0: function contextual_help($route_name, RouteMatchInterface $route_match) {
Chris@0:   switch ($route_name) {
Chris@0:     case 'help.page.contextual':
Chris@0:       $output = '';
Chris@0:       $output .= '<h3>' . t('About') . '</h3>';
Chris@0:       $output .= '<p>' . t('The Contextual links module gives users with the <em>Use contextual links</em> permission quick access to tasks associated with certain areas of pages on your site. For example, a menu displayed as a block has links to edit the menu and configure the block. For more information, see the <a href=":contextual">online documentation for the Contextual Links module</a>.', [':contextual' => 'https://www.drupal.org/documentation/modules/contextual']) . '</p>';
Chris@0:       $output .= '<h3>' . t('Uses') . '</h3>';
Chris@0:       $output .= '<dl>';
Chris@0:       $output .= '<dt>' . t('Displaying contextual links') . '</dt>';
Chris@0:       $output .= '<dd>';
Chris@0:       $output .= t('Contextual links for an area on a page are displayed using a contextual links button. There are two ways to make the contextual links button visible:');
Chris@0:       $output .= '<ol>';
Chris@0:       $sample_picture = [
Chris@0:         '#theme' => 'image',
Chris@0:         '#uri' => 'core/misc/icons/bebebe/pencil.svg',
Chris@17:         '#alt' => t('contextual links button'),
Chris@0:       ];
Chris@0:       $sample_picture = \Drupal::service('renderer')->render($sample_picture);
Chris@0:       $output .= '<li>' . t('Hovering over the area of interest will temporarily make the contextual links button visible (which looks like a pencil in most themes, and is normally displayed in the upper right corner of the area). The icon typically looks like this: @picture', ['@picture' => $sample_picture]) . '</li>';
Chris@18:       $output .= '<li>' . t('If you have the <a href=":toolbar">Toolbar module</a> enabled, clicking the contextual links button in the toolbar (which looks like a pencil) will make all contextual links buttons on the page visible. Clicking this button again will toggle them to invisible.', [':toolbar' => (\Drupal::moduleHandler()->moduleExists('toolbar')) ? Url::fromRoute('help.page', ['name' => 'toolbar'])->toString() : '#']) . '</li>';
Chris@0:       $output .= '</ol>';
Chris@0:       $output .= t('Once the contextual links button for the area of interest is visible, click the button to display the links.');
Chris@0:       $output .= '</dd>';
Chris@0:       $output .= '</dl>';
Chris@0:       return $output;
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * Implements hook_preprocess().
Chris@0:  *
Chris@0:  * @see contextual_pre_render_placeholder()
Chris@0:  * @see contextual_page_attachments()
Chris@0:  * @see \Drupal\contextual\ContextualController::render()
Chris@0:  */
Chris@0: function contextual_preprocess(&$variables, $hook, $info) {
Chris@0:   $variables['#cache']['contexts'][] = 'user.permissions';
Chris@0:   if (!\Drupal::currentUser()->hasPermission('access contextual links')) {
Chris@0:     return;
Chris@0:   }
Chris@0: 
Chris@0:   // Determine the primary theme function argument.
Chris@0:   if (!empty($info['variables'])) {
Chris@0:     $keys = array_keys($info['variables']);
Chris@0:     $key = $keys[0];
Chris@0:   }
Chris@0:   elseif (!empty($info['render element'])) {
Chris@0:     $key = $info['render element'];
Chris@0:   }
Chris@0:   if (!empty($key) && isset($variables[$key])) {
Chris@0:     $element = $variables[$key];
Chris@0:   }
Chris@0: 
Chris@0:   if (isset($element) && is_array($element) && !empty($element['#contextual_links'])) {
Chris@0:     // Mark this element as potentially having contextual links attached to it.
Chris@0:     $variables['attributes']['class'][] = 'contextual-region';
Chris@0: 
Chris@0:     // Renders a contextual links placeholder unconditionally, thus not breaking
Chris@0:     // the render cache. Although the empty placeholder is rendered for all
Chris@0:     // users, contextual_page_attachments() only adds the asset library for
Chris@0:     // users with the 'access contextual links' permission, thus preventing
Chris@0:     // unnecessary HTTP requests for users without that permission.
Chris@0:     $variables['title_suffix']['contextual_links'] = [
Chris@0:       '#type' => 'contextual_links_placeholder',
Chris@0:       '#id' => _contextual_links_to_id($element['#contextual_links']),
Chris@0:     ];
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * Implements hook_contextual_links_view_alter().
Chris@0:  *
Chris@0:  * @see \Drupal\contextual\Plugin\views\field\ContextualLinks::render()
Chris@0:  */
Chris@0: function contextual_contextual_links_view_alter(&$element, $items) {
Chris@0:   if (isset($element['#contextual_links']['contextual'])) {
Chris@0:     $encoded_links = $element['#contextual_links']['contextual']['metadata']['contextual-views-field-links'];
Chris@0:     $element['#links'] = Json::decode(rawurldecode($encoded_links));
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * Serializes #contextual_links property value array to a string.
Chris@0:  *
Chris@0:  * Examples:
Chris@0:  *  - node:node=1:langcode=en
Chris@0:  *  - views_ui_edit:view=frontpage:location=page&view_name=frontpage&view_display_id=page_1&langcode=en
Chris@0:  *  - menu:menu=tools:langcode=en|block:block=bartik.tools:langcode=en
Chris@0:  *
Chris@0:  * So, expressed in a pattern:
Chris@0:  *  <group>:<route parameters>:<metadata>
Chris@0:  *
Chris@0:  * The route parameters and options are encoded as query strings.
Chris@0:  *
Chris@0:  * @param array $contextual_links
Chris@0:  *   The $element['#contextual_links'] value for some render element.
Chris@0:  *
Chris@0:  * @return string
Chris@0:  *   A serialized representation of a #contextual_links property value array for
Chris@0:  *   use in a data- attribute.
Chris@0:  */
Chris@0: function _contextual_links_to_id($contextual_links) {
Chris@0:   $ids = [];
Chris@0:   $langcode = \Drupal::languageManager()->getCurrentLanguage(LanguageInterface::TYPE_URL)->getId();
Chris@0:   foreach ($contextual_links as $group => $args) {
Chris@0:     $route_parameters = UrlHelper::buildQuery($args['route_parameters']);
Chris@0:     $args += ['metadata' => []];
Chris@0:     // Add the current URL language to metadata so a different ID will be
Chris@0:     // computed when URLs vary by language. This allows to store different
Chris@0:     // language-aware contextual links on the client side.
Chris@0:     $args['metadata'] += ['langcode' => $langcode];
Chris@0:     $metadata = UrlHelper::buildQuery($args['metadata']);
Chris@0:     $ids[] = "{$group}:{$route_parameters}:{$metadata}";
Chris@0:   }
Chris@0:   return implode('|', $ids);
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * Unserializes the result of _contextual_links_to_id().
Chris@0:  *
Chris@17:  * Note that $id is user input. Before calling this method the ID should be
Chris@17:  * checked against the token stored in the 'data-contextual-token' attribute
Chris@17:  * which is passed via the 'tokens' request parameter to
Chris@17:  * \Drupal\contextual\ContextualController::render().
Chris@0:  *
Chris@0:  * @param string $id
Chris@0:  *   A serialized representation of a #contextual_links property value array.
Chris@0:  *
Chris@0:  * @return array
Chris@0:  *   The value for a #contextual_links property.
Chris@17:  *
Chris@17:  * @see _contextual_links_to_id()
Chris@17:  * @see \Drupal\contextual\ContextualController::render()
Chris@0:  */
Chris@0: function _contextual_id_to_links($id) {
Chris@0:   $contextual_links = [];
Chris@0:   $contexts = explode('|', $id);
Chris@0:   foreach ($contexts as $context) {
Chris@0:     list($group, $route_parameters_raw, $metadata_raw) = explode(':', $context);
Chris@0:     parse_str($route_parameters_raw, $route_parameters);
Chris@0:     $metadata = [];
Chris@0:     parse_str($metadata_raw, $metadata);
Chris@0:     $contextual_links[$group] = [
Chris@0:       'route_parameters' => $route_parameters,
Chris@0:       'metadata' => $metadata,
Chris@0:     ];
Chris@0:   }
Chris@0:   return $contextual_links;
Chris@0: }