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class Link in Drupal 8

Same name in this branch
  1. 8 core/lib/Drupal/Core/Link.php \Drupal\Core\Link
  2. 8 core/modules/jsonapi/src/JsonApiResource/Link.php \Drupal\jsonapi\JsonApiResource\Link
  3. 8 core/lib/Drupal/Core/Render/Element/Link.php \Drupal\Core\Render\Element\Link
Same name and namespace in other branches
  1. 9 core/lib/Drupal/Core/Render/Element/Link.php \Drupal\Core\Render\Element\Link

Provides a link render element.

Properties:

Usage example:

$build['examples_link'] = [
  '#title' => $this
    ->t('Examples'),
  '#type' => 'link',
  '#url' => \Drupal\Core\Url::fromRoute('examples.description'),
];

Plugin annotation

@RenderElement("link");

Hierarchy

Expanded class hierarchy of Link

4 files declare their use of Link
CommentLazyBuilders.php in core/modules/comment/src/CommentLazyBuilders.php
common.inc in core/includes/common.inc
Common functions that many Drupal modules will need to reference.
FunctionsTest.php in core/modules/system/tests/src/Kernel/Theme/FunctionsTest.php
NodeViewBuilder.php in core/modules/node/src/NodeViewBuilder.php
18 string references to 'Link'
CKEditorPluginManagerTest::providerGetEnabledButtons in core/modules/ckeditor/tests/src/Unit/CKEditorPluginManagerTest.php
Provides a list of configs to test.
contextual.views.schema.yml in core/modules/contextual/config/schema/contextual.views.schema.yml
core/modules/contextual/config/schema/contextual.views.schema.yml
DrupalLink::getButtons in core/modules/ckeditor/src/Plugin/CKEditorPlugin/DrupalLink.php
Returns the buttons that this plugin provides, along with metadata.
EntityResource::addLinkHeaders in core/modules/rest/src/Plugin/rest/resource/EntityResource.php
Adds link headers to a response.
EntityResourceTestBase::assert406Response in core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
Asserts a 406 response… or in some cases a 403 response, because weirdness.

... See full list

96 #type uses of Link
AggregatorFeedBlock::build in core/modules/aggregator/src/Plugin/Block/AggregatorFeedBlock.php
Builds and returns the renderable array for this block plugin.
AggregatorTitleFormatter::viewElements in core/modules/aggregator/src/Plugin/Field/FieldFormatter/AggregatorTitleFormatter.php
Builds a renderable array for a field value.
AjaxTestController::dialog in core/modules/system/tests/modules/ajax_test/src/Controller/AjaxTestController.php
Returns a render array of form elements and links for dialog.
AjaxTestController::dialogContents in core/modules/system/tests/modules/ajax_test/src/Controller/AjaxTestController.php
Example content for dialog testing.
authorize.php in core/authorize.php
Administrative script for running authorized file operations.

... See full list

File

core/lib/Drupal/Core/Render/Element/Link.php, line 30

Namespace

Drupal\Core\Render\Element
View source 
class Link extends RenderElement {

  /**
   * {@inheritdoc}
   */
  public function getInfo() {
    $class = get_class($this);
    return [
      '#pre_render' => [
        [
          $class,
          'preRenderLink',
        ],
      ],
    ];
  }

  /**
   * Pre-render callback: Renders a link into #markup.
   *
   * Doing so during pre_render gives modules a chance to alter the link parts.
   *
   * @param array $element
   *   A structured array whose keys form the arguments to
   *   \Drupal\Core\Utility\LinkGeneratorInterface::generate():
   *   - #title: The link text.
   *   - #url: The URL info either pointing to a route or a non routed path.
   *   - #options: (optional) An array of options to pass to the link generator.
   *
   * @return array
   *   The passed-in element containing a rendered link in '#markup'.
   */
  public static function preRenderLink($element) {

    // By default, link options to pass to the link generator are normally set
    // in #options.
    $element += [
      '#options' => [],
    ];

    // However, within the scope of renderable elements, #attributes is a valid
    // way to specify attributes, too. Take them into account, but do not override
    // attributes from #options.
    if (isset($element['#attributes'])) {
      $element['#options'] += [
        'attributes' => [],
      ];
      $element['#options']['attributes'] += $element['#attributes'];
    }

    // This #pre_render callback can be invoked from inside or outside of a Form
    // API context, and depending on that, a HTML ID may be already set in
    // different locations. #options should have precedence over Form API's #id.
    // #attributes have been taken over into #options above already.
    if (isset($element['#options']['attributes']['id'])) {
      $element['#id'] = $element['#options']['attributes']['id'];
    }
    elseif (isset($element['#id'])) {
      $element['#options']['attributes']['id'] = $element['#id'];
    }

    // Conditionally invoke self::preRenderAjaxForm(), if #ajax is set.
    if (isset($element['#ajax']) && !isset($element['#ajax_processed'])) {

      // If no HTML ID was found above, automatically create one.
      if (!isset($element['#id'])) {
        $element['#id'] = $element['#options']['attributes']['id'] = HtmlUtility::getUniqueId('ajax-link');
      }
      $element = static::preRenderAjaxForm($element);
    }
    if (!empty($element['#url']) && $element['#url'] instanceof CoreUrl) {
      $options = NestedArray::mergeDeep($element['#url']
        ->getOptions(), $element['#options']);

      /** @var \Drupal\Core\Utility\LinkGenerator $link_generator */
      $link_generator = \Drupal::service('link_generator');
      $generated_link = $link_generator
        ->generate($element['#title'], $element['#url']
        ->setOptions($options));
      $element['#markup'] = $generated_link;
      $generated_link
        ->merge(BubbleableMetadata::createFromRenderArray($element))
        ->applyTo($element);
    }
    return $element;
  }

  /**
   * Pre-render callback: Collects child links into a single array.
   *
   * This method can be added as a pre_render callback for a renderable array,
   * usually one which will be themed by links.html.twig. It iterates through
   * all unrendered children of the element, collects any #links properties it
   * finds, merges them into the parent element's #links array, and prevents
   * those children from being rendered separately.
   *
   * The purpose of this is to allow links to be logically grouped into related
   * categories, so that each child group can be rendered as its own list of
   * links if drupal_render() is called on it, but calling drupal_render() on
   * the parent element will still produce a single list containing all the
   * remaining links, regardless of what group they were in.
   *
   * A typical example comes from node links, which are stored in a renderable
   * array similar to this:
   * @code
   * $build['links'] = array(
   *   '#theme' => 'links__node',
   *   '#pre_render' => array(Link::class, 'preRenderLinks'),
   *   'comment' => array(
   *     '#theme' => 'links__node__comment',
   *     '#links' => array(
   *       // An array of links associated with node comments, suitable for
   *       // passing in to links.html.twig.
   *     ),
   *   ),
   *   'statistics' => array(
   *     '#theme' => 'links__node__statistics',
   *     '#links' => array(
   *       // An array of links associated with node statistics, suitable for
   *       // passing in to links.html.twig.
   *     ),
   *   ),
   *   'translation' => array(
   *     '#theme' => 'links__node__translation',
   *     '#links' => array(
   *       // An array of links associated with node translation, suitable for
   *       // passing in to links.html.twig.
   *     ),
   *   ),
   * );
   * @endcode
   *
   * In this example, the links are grouped by functionality, which can be
   * helpful to themers who want to display certain kinds of links
   * independently. For example, adding this code to node.html.twig will result
   * in the comment links being rendered as a single list:
   * @code
   * {{ content.links.comment }}
   * @endcode
   *
   * (where a node's content has been transformed into $content before handing
   * control to the node.html.twig template).
   *
   * The preRenderLinks method defined here allows the above flexibility, but
   * also allows the following code to be used to render all remaining links
   * into a single list, regardless of their group:
   * @code
   * {{ content.links }}
   * @endcode
   *
   * In the above example, this will result in the statistics and translation
   * links being rendered together in a single list (but not the comment links,
   * which were rendered previously on their own).
   *
   * Because of the way this method works, the individual properties of each
   * group (for example, a group-specific #theme property such as
   * 'links__node__comment' in the example above, or any other property such as
   * #attributes or #pre_render that is attached to it) are only used when that
   * group is rendered on its own. When the group is rendered together with
   * other children, these child-specific properties are ignored, and only the
   * overall properties of the parent are used.
   *
   * @param array $element
   *   Render array containing child links to group.
   *
   * @return array
   *   Render array containing child links grouped into a single array.
   */
  public static function preRenderLinks($element) {
    $element += [
      '#links' => [],
      '#attached' => [],
    ];
    foreach (Element::children($element) as $key) {
      $child =& $element[$key];

      // If the child has links which have not been printed yet and the user has
      // access to it, merge its links in to the parent.
      if (isset($child['#links']) && empty($child['#printed']) && Element::isVisibleElement($child)) {
        $element['#links'] += $child['#links'];

        // Mark the child as having been printed already (so that its links
        // cannot be mistakenly rendered twice).
        $child['#printed'] = TRUE;
      }

      // Merge attachments.
      if (isset($child['#attached'])) {
        $element['#attached'] = BubbleableMetadata::mergeAttachments($element['#attached'], $child['#attached']);
      }
    }
    return $element;
  }

}

Members

Namesort descending Modifiers Type Description Overrides
DependencySerializationTrait::$_entityStorages protected property An array of entity type IDs keyed by the property name of their storages.
DependencySerializationTrait::$_serviceIds protected property An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep public function 1
DependencySerializationTrait::__wakeup public function 2
Link::getInfo public function Returns the element properties for this element. Overrides ElementInterface::getInfo 2
Link::preRenderLink public static function Pre-render callback: Renders a link into #markup.
Link::preRenderLinks public static function Pre-render callback: Collects child links into a single array.
MessengerTrait::$messenger protected property The messenger. 29
MessengerTrait::messenger public function Gets the messenger. 29
MessengerTrait::setMessenger public function Sets the messenger.
PluginBase::$configuration protected property Configuration information passed into the plugin. 1
PluginBase::$pluginDefinition protected property The plugin implementation definition. 1
PluginBase::$pluginId protected property The plugin_id.
PluginBase::DERIVATIVE_SEPARATOR constant A string which is used to separate base plugin IDs from the derivative ID.
PluginBase::getBaseId public function Gets the base_plugin_id of the plugin instance. Overrides DerivativeInspectionInterface::getBaseId
PluginBase::getDerivativeId public function Gets the derivative_id of the plugin instance. Overrides DerivativeInspectionInterface::getDerivativeId
PluginBase::getPluginDefinition public function Gets the definition of the plugin implementation. Overrides PluginInspectionInterface::getPluginDefinition 3
PluginBase::getPluginId public function Gets the plugin_id of the plugin instance. Overrides PluginInspectionInterface::getPluginId
PluginBase::isConfigurable public function Determines if the plugin is configurable.
PluginBase::__construct public function Constructs a \Drupal\Component\Plugin\PluginBase object. 92
RenderElement::preRenderAjaxForm public static function Adds Ajax information about an element to communicate with JavaScript.
RenderElement::preRenderGroup public static function Adds members of this group as actual elements for rendering.
RenderElement::processAjaxForm public static function Form element processing handler for the #ajax form property. 1
RenderElement::processGroup public static function Arranges elements into groups.
RenderElement::setAttributes public static function Sets a form element's class attribute. Overrides ElementInterface::setAttributes
StringTranslationTrait::$stringTranslation protected property The string translation service. 1
StringTranslationTrait::formatPlural protected function Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals protected function Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation protected function Gets the string translation service.
StringTranslationTrait::setStringTranslation public function Sets the string translation service to use. 2
StringTranslationTrait::t protected function Translates a string to the current language or to a given language.