class LinkGenerator in Drupal 8

Provides a class which generates a link with route names and parameters.

Hierarchy

• class \Drupal\Core\Utility\LinkGenerator implements LinkGeneratorInterface

2 files declare their use of LinkGenerator

FieldPluginBaseTest.php in core/modules/views/tests/src/Unit/Plugin/field/FieldPluginBaseTest.php

Contains \Drupal\Tests\views\Unit\Plugin\field\FieldPluginBaseTest.

LinkGeneratorTest.php in core/tests/Drupal/Tests/Core/Utility/LinkGeneratorTest.php

1 string reference to 'LinkGenerator'

core.services.yml in core/core.services.yml

core/core.services.yml

1 service uses LinkGenerator

link_generator in core/core.services.yml

Drupal\Core\Utility\LinkGenerator

File

core/lib/Drupal/Core/Utility/LinkGenerator.php, line 21

Namespace

Drupal\Core\Utility

class LinkGenerator implements LinkGeneratorInterface {

  /**
   * The url generator.
   *
   * @var \Drupal\Core\Routing\UrlGeneratorInterface
   */
  protected $urlGenerator;

  /**
   * The module handler firing the route_link alter hook.
   *
   * @var \Drupal\Core\Extension\ModuleHandlerInterface
   */
  protected $moduleHandler;

  /**
   * The renderer service.
   *
   * @var \Drupal\Core\Render\RendererInterface
   */
  protected $renderer;

  /**
   * Constructs a LinkGenerator instance.
   *
   * @param \Drupal\Core\Routing\UrlGeneratorInterface $url_generator
   *   The url generator.
   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
   *   The module handler.
   * @param \Drupal\Core\Render\RendererInterface $renderer
   *   The renderer service.
   */
  public function __construct(UrlGeneratorInterface $url_generator, ModuleHandlerInterface $module_handler, RendererInterface $renderer) {
    $this->urlGenerator = $url_generator;
    $this->moduleHandler = $module_handler;
    $this->renderer = $renderer;
  }

  /**
   * {@inheritdoc}
   */
  public function generateFromLink(Link $link) {
    return $this
      ->generate($link
      ->getText(), $link
      ->getUrl());
  }

  /**
   * {@inheritdoc}
   *
   * For anonymous users, the "active" class will be calculated on the server,
   * because most sites serve each anonymous user the same cached page anyway.
   * For authenticated users, the "active" class will be calculated on the
   * client (through JavaScript), only data- attributes are added to links to
   * prevent breaking the render cache. The JavaScript is added in
   * system_page_attachments().
   *
   * @see system_page_attachments()
   */
  public function generate($text, Url $url) {

    // The link generator should not modify the original URL object, this
    // ensures consistent rendering.
    // @see https://www.drupal.org/node/2842399
    $url = clone $url;

    // Performance: avoid Url::toString() needing to retrieve the URL generator
    // service from the container.
    $url
      ->setUrlGenerator($this->urlGenerator);
    if (is_array($text)) {
      $text = $this->renderer
        ->render($text);
    }

    // Start building a structured representation of our link to be altered later.
    $variables = [
      'text' => $text,
      'url' => $url,
      'options' => $url
        ->getOptions(),
    ];

    // Merge in default options.
    $variables['options'] += [
      'attributes' => [],
      'query' => [],
      'language' => NULL,
      'set_active_class' => FALSE,
      'absolute' => FALSE,
    ];

    // Add a hreflang attribute if we know the language of this link's url and
    // hreflang has not already been set.
    if (!empty($variables['options']['language']) && !isset($variables['options']['attributes']['hreflang'])) {
      $variables['options']['attributes']['hreflang'] = $variables['options']['language']
        ->getId();
    }

    // Ensure that query values are strings.
    array_walk($variables['options']['query'], function (&$value) {
      if ($value instanceof MarkupInterface) {
        $value = (string) $value;
      }
    });

    // Set the "active" class if the 'set_active_class' option is not empty.
    if (!empty($variables['options']['set_active_class']) && !$url
      ->isExternal()) {

      // Add a "data-drupal-link-query" attribute to let the
      // drupal.active-link library know the query in a standardized manner.
      if (!empty($variables['options']['query'])) {
        $query = $variables['options']['query'];
        ksort($query);
        $variables['options']['attributes']['data-drupal-link-query'] = Json::encode($query);
      }

      // Add a "data-drupal-link-system-path" attribute to let the
      // drupal.active-link library know the path in a standardized manner.
      if ($url
        ->isRouted() && !isset($variables['options']['attributes']['data-drupal-link-system-path'])) {

        // @todo System path is deprecated - use the route name and parameters.
        $system_path = $url
          ->getInternalPath();

        // Special case for the front page.
        if ($url
          ->getRouteName() === '<front>') {
          $system_path = '<front>';
        }
        if (!empty($system_path)) {
          $variables['options']['attributes']['data-drupal-link-system-path'] = $system_path;
        }
      }
    }

    // Remove all HTML and PHP tags from a tooltip, calling expensive strip_tags()
    // only when a quick strpos() gives suspicion tags are present.
    if (isset($variables['options']['attributes']['title']) && strpos($variables['options']['attributes']['title'], '<') !== FALSE) {
      $variables['options']['attributes']['title'] = strip_tags($variables['options']['attributes']['title']);
    }

    // Allow other modules to modify the structure of the link.
    $this->moduleHandler
      ->alter('link', $variables);
    $url = $variables['url'];

    // Move attributes out of options since generateFromRoute() doesn't need
    // them. Make sure the "href" comes first for testing purposes.
    $attributes = [
      'href' => '',
    ] + $variables['options']['attributes'];
    unset($variables['options']['attributes']);
    $url
      ->setOptions($variables['options']);

    // External URLs can not have cacheable metadata.
    if ($url
      ->isExternal()) {
      $generated_link = new GeneratedLink();
      $attributes['href'] = $url
        ->toString(FALSE);
      return $this
        ->doGenerate($generated_link, $attributes, $variables);
    }
    if ($url
      ->isRouted() && $url
      ->getRouteName() === '<nolink>') {
      $generated_link = new GeneratedNoLink();
      unset($attributes['href']);
      return $this
        ->doGenerate($generated_link, $attributes, $variables);
    }
    if ($url
      ->isRouted() && $url
      ->getRouteName() === '<button>') {
      $generated_link = new GeneratedButton();
      $attributes['type'] = 'button';
      unset($attributes['href']);
      return $this
        ->doGenerate($generated_link, $attributes, $variables);
    }
    $generated_url = $url
      ->toString(TRUE);
    $generated_link = GeneratedLink::createFromObject($generated_url);

    // The result of the URL generator is a plain-text URL to use as the href
    // attribute, and it is escaped by \Drupal\Core\Template\Attribute.
    $attributes['href'] = $generated_url
      ->getGeneratedUrl();
    return $this
      ->doGenerate($generated_link, $attributes, $variables);
  }

  /**
   * Generates the link.
   *
   * @param Drupal\Core\GeneratedLink $generated_link
   *   The generated link, along with its associated cacheability metadata.
   * @param array $attributes
   *   The attributes of the generated link.
   * @param array $variables
   *   The link text, url, and other options.
   *
   * @return Drupal\Core\GeneratedLink
   *   The generated link, along with its associated cacheability metadata.
   */
  protected function doGenerate($generated_link, $attributes, $variables) {
    if (!$variables['text'] instanceof MarkupInterface) {
      $variables['text'] = Html::escape($variables['text']);
    }
    $attributes = new Attribute($attributes);

    // This is safe because Attribute does escaping and $variables['text'] is
    // either rendered or escaped.
    return $generated_link
      ->setGeneratedLink('<' . $generated_link::TAG . $attributes . '>' . $variables['text'] . '</' . $generated_link::TAG . '>');
  }

}

Members

Name	Modifiers	Type	Description	Overrides
LinkGenerator::$moduleHandler	protected	property	The module handler firing the route_link alter hook.
LinkGenerator::$renderer	protected	property	The renderer service.
LinkGenerator::$urlGenerator	protected	property	The url generator.
LinkGenerator::doGenerate	protected	function	Generates the link.
LinkGenerator::generate	public	function	For anonymous users, the "active" class will be calculated on the server, because most sites serve each anonymous user the same cached page anyway. For authenticated users, the "active" class will be calculated on the client… Overrides LinkGeneratorInterface::generate
LinkGenerator::generateFromLink	public	function	Renders a link from a link object. Overrides LinkGeneratorInterface::generateFromLink
LinkGenerator::__construct	public	function	Constructs a LinkGenerator instance.