contextual.module

<?php


/**
 * @file
 */
use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Language\LanguageInterface;

/**
 * Implements hook_preprocess().
 *
 * @see \Drupal\contextual\Element\ContextualLinksPlaceholder
 * @see contextual_page_attachments()
 * @see \Drupal\contextual\ContextualController::render()
 */
function contextual_preprocess(&$variables, $hook, $info) {
    // Determine the primary theme function argument.
    if (!empty($info['variables'])) {
        $keys = array_keys($info['variables']);
        $key = $keys[0];
    }
    elseif (!empty($info['render element'])) {
        $key = $info['render element'];
    }
    if (!empty($key) && isset($variables[$key])) {
        $element = $variables[$key];
    }
    if (isset($element) && is_array($element) && !empty($element['#contextual_links'])) {
        $variables['#cache']['contexts'][] = 'user.permissions';
        if (\Drupal::currentUser()->hasPermission('access contextual links')) {
            // Mark this element as potentially having contextual links attached to it.
            $variables['attributes']['class'][] = 'contextual-region';
            // Renders a contextual links placeholder unconditionally, thus not breaking
            // the render cache. Although the empty placeholder is rendered for all
            // users, contextual_page_attachments() only adds the asset library for
            // users with the 'access contextual links' permission, thus preventing
            // unnecessary HTTP requests for users without that permission.
            $variables['title_suffix']['contextual_links'] = [
                '#type' => 'contextual_links_placeholder',
                '#id' => _contextual_links_to_id($element['#contextual_links']),
            ];
        }
    }
}

/**
 * Serializes #contextual_links property value array to a string.
 *
 * Examples:
 *  - node:node=1:langcode=en
 *  - views_ui_edit:view=frontpage:location=page&view_name=frontpage&view_display_id=page_1&langcode=en
 *  - menu:menu=tools:langcode=en|block:block=olivero.tools:langcode=en
 *
 * So, expressed in a pattern:
 *  <group>:<route parameters>:<metadata>
 *
 * The route parameters and options are encoded as query strings.
 *
 * @param array $contextual_links
 *   The $element['#contextual_links'] value for some render element.
 *
 * @return string
 *   A serialized representation of a #contextual_links property value array for
 *   use in a data- attribute.
 */
function _contextual_links_to_id($contextual_links) {
    $ids = [];
    $langcode = \Drupal::languageManager()->getCurrentLanguage(LanguageInterface::TYPE_URL)
        ->getId();
    foreach ($contextual_links as $group => $args) {
        $route_parameters = UrlHelper::buildQuery($args['route_parameters']);
        $args += [
            'metadata' => [],
        ];
        // Add the current URL language to metadata so a different ID will be
        // computed when URLs vary by language. This allows to store different
        // language-aware contextual links on the client side.
        $args['metadata'] += [
            'langcode' => $langcode,
        ];
        $metadata = UrlHelper::buildQuery($args['metadata']);
        $ids[] = "{$group}:{$route_parameters}:{$metadata}";
    }
    return implode('|', $ids);
}

/**
 * Unserializes the result of _contextual_links_to_id().
 *
 * Note that $id is user input. Before calling this method the ID should be
 * checked against the token stored in the 'data-contextual-token' attribute
 * which is passed via the 'tokens' request parameter to
 * \Drupal\contextual\ContextualController::render().
 *
 * @param string $id
 *   A serialized representation of a #contextual_links property value array.
 *
 * @return array
 *   The value for a #contextual_links property.
 *
 * @see _contextual_links_to_id()
 * @see \Drupal\contextual\ContextualController::render()
 */
function _contextual_id_to_links($id) {
    $contextual_links = [];
    $contexts = explode('|', $id);
    foreach ($contexts as $context) {
        [
            $group,
            $route_parameters_raw,
            $metadata_raw,
        ] = explode(':', $context);
        parse_str($route_parameters_raw, $route_parameters);
        $metadata = [];
        parse_str($metadata_raw, $metadata);
        $contextual_links[$group] = [
            'route_parameters' => $route_parameters,
            'metadata' => $metadata,
        ];
    }
    return $contextual_links;
}