final class LinkCollection in Drupal 8

Same name and namespace in other branches

9 core/modules/jsonapi/src/JsonApiResource/LinkCollection.php \Drupal\jsonapi\JsonApiResource\LinkCollection

Contains a set of JSON:API Link objects.

@internal JSON:API maintains no PHP API. The API is the HTTP API. This class may change at any time and could break any dependencies on it.

Hierarchy

class \Drupal\jsonapi\JsonApiResource\LinkCollection implements \Drupal\jsonapi\JsonApiResource\IteratorAggregate

Expanded class hierarchy of LinkCollection

File

core/modules/jsonapi/src/JsonApiResource/LinkCollection.php, line 16

Namespace

Drupal\jsonapi\JsonApiResource

View source

final class LinkCollection implements \IteratorAggregate {

  /**
   * The links in the collection, keyed by unique strings.
   *
   * @var \Drupal\jsonapi\JsonApiResource\Link[]
   */
  protected $links;

  /**
   * The link context.
   *
   * All links objects exist within a context object. Links form a relationship
   * between a source IRI and target IRI. A context is the link's source.
   *
   * @var \Drupal\jsonapi\JsonApiResource\JsonApiDocumentTopLevel|\Drupal\jsonapi\JsonApiResource\ResourceObject|\Drupal\jsonapi\JsonApiResource\Relationship
   *
   * @see https://tools.ietf.org/html/rfc8288#section-3.2
   */
  protected $context;

  /**
   * LinkCollection constructor.
   *
   * @param \Drupal\jsonapi\JsonApiResource\Link[] $links
   *   An associated array of key names and JSON:API Link objects.
   * @param \Drupal\jsonapi\JsonApiResource\JsonApiDocumentTopLevel|\Drupal\jsonapi\JsonApiResource\ResourceObject|\Drupal\jsonapi\JsonApiResource\Relationship $context
   *   (internal use only) The context object. Use the self::withContext()
   *   method to establish a context. This should be done automatically when
   *   a LinkCollection is passed into a context object.
   */
  public function __construct(array $links, $context = NULL) {
    assert(Inspector::assertAll(function ($key) {
      return static::validKey($key);
    }, array_keys($links)));
    assert(Inspector::assertAll(function ($link) {
      return $link instanceof Link || is_array($link) && Inspector::assertAllObjects($link, Link::class);
    }, $links));
    assert(is_null($context) || Inspector::assertAllObjects([
      $context,
    ], JsonApiDocumentTopLevel::class, ResourceObject::class, Relationship::class));
    ksort($links);
    $this->links = array_map(function ($link) {
      return is_array($link) ? $link : [
        $link,
      ];
    }, $links);
    $this->context = $context;
  }

  /**
   * {@inheritdoc}
   */
  public function getIterator() {
    assert(!is_null($this->context), 'A LinkCollection is invalid unless a context has been established.');
    return new \ArrayIterator($this->links);
  }

  /**
   * Gets a new LinkCollection with the given link inserted.
   *
   * @param string $key
   *   A key for the link. If the key already exists and the link shares an
   *   href, link relation type and attributes with an existing link with that
   *   key, those links will be merged together.
   * @param \Drupal\jsonapi\JsonApiResource\Link $new_link
   *   The link to insert.
   *
   * @return static
   *   A new LinkCollection with the given link inserted or merged with the
   *   current set of links.
   */
  public function withLink($key, Link $new_link) {
    assert(static::validKey($key));
    $merged = $this->links;
    if (isset($merged[$key])) {
      foreach ($merged[$key] as $index => $existing_link) {
        if (Link::compare($existing_link, $new_link) === 0) {
          $merged[$key][$index] = Link::merge($existing_link, $new_link);
          return new static($merged, $this->context);
        }
      }
    }
    $merged[$key][] = $new_link;
    return new static($merged, $this->context);
  }

  /**
   * Whether a link with the given key exists.
   *
   * @param string $key
   *   The key.
   *
   * @return bool
   *   TRUE if a link with the given key exist, FALSE otherwise.
   */
  public function hasLinkWithKey($key) {
    return array_key_exists($key, $this->links);
  }

  /**
   * Establishes a new context for a LinkCollection.
   *
   * @param \Drupal\jsonapi\JsonApiResource\JsonApiDocumentTopLevel|\Drupal\jsonapi\JsonApiResource\ResourceObject|\Drupal\jsonapi\JsonApiResource\Relationship $context
   *   The new context object.
   *
   * @return static
   *   A new LinkCollection with the given context.
   */
  public function withContext($context) {
    return new static($this->links, $context);
  }

  /**
   * Gets the LinkCollection's context object.
   *
   * @return \Drupal\jsonapi\JsonApiResource\JsonApiDocumentTopLevel|\Drupal\jsonapi\JsonApiResource\ResourceObject|\Drupal\jsonapi\JsonApiResource\Relationship
   *   The LinkCollection's context.
   */
  public function getContext() {
    assert(!is_null($this->context), 'A LinkCollection is invalid unless a context has been established.');
    return $this->context;
  }

  /**
   * Filters a LinkCollection using the provided callback.
   *
   * @param callable $f
   *   The filter callback. The callback has the signature below.
   *
   * @code
   *   boolean callback(string $key, \Drupal\jsonapi\JsonApiResource\Link $link, mixed $context))
   * @endcode
   *
   * @return \Drupal\jsonapi\JsonApiResource\LinkCollection
   *   A new, filtered LinkCollection.
   */
  public function filter(callable $f) {
    $links = iterator_to_array($this);
    $filtered = array_reduce(array_keys($links), function ($filtered, $key) use ($links, $f) {
      if ($f($key, $links[$key], $this->context)) {
        $filtered[$key] = $links[$key];
      }
      return $filtered;
    }, []);
    return new LinkCollection($filtered, $this->context);
  }

  /**
   * Merges two LinkCollections.
   *
   * @param \Drupal\jsonapi\JsonApiResource\LinkCollection $a
   *   The first link collection.
   * @param \Drupal\jsonapi\JsonApiResource\LinkCollection $b
   *   The second link collection.
   *
   * @return \Drupal\jsonapi\JsonApiResource\LinkCollection
   *   A new LinkCollection with the links of both inputs.
   */
  public static function merge(LinkCollection $a, LinkCollection $b) {
    assert($a
      ->getContext() === $b
      ->getContext());
    $merged = new LinkCollection([], $a
      ->getContext());
    foreach ($a as $key => $links) {
      $merged = array_reduce($links, function (self $merged, Link $link) use ($key) {
        return $merged
          ->withLink($key, $link);
      }, $merged);
    }
    foreach ($b as $key => $links) {
      $merged = array_reduce($links, function (self $merged, Link $link) use ($key) {
        return $merged
          ->withLink($key, $link);
      }, $merged);
    }
    return $merged;
  }

  /**
   * Ensures that a link key is valid.
   *
   * @param string $key
   *   A key name.
   *
   * @return bool
   *   TRUE if the key is valid, FALSE otherwise.
   */
  protected static function validKey($key) {
    return is_string($key) && !is_numeric($key) && strpos($key, ':') === FALSE;
  }

}

Members

Name	Modifiers	Type	Description
LinkCollection::$context	protected	property	The link context.
LinkCollection::$links	protected	property	The links in the collection, keyed by unique strings.
LinkCollection::filter	public	function	Filters a LinkCollection using the provided callback.
LinkCollection::getContext	public	function	Gets the LinkCollection's context object.
LinkCollection::getIterator	public	function
LinkCollection::hasLinkWithKey	public	function	Whether a link with the given key exists.
LinkCollection::merge	public static	function	Merges two LinkCollections.
LinkCollection::validKey	protected static	function	Ensures that a link key is valid.
LinkCollection::withContext	public	function	Establishes a new context for a LinkCollection.
LinkCollection::withLink	public	function	Gets a new LinkCollection with the given link inserted.
LinkCollection::__construct	public	function	LinkCollection constructor.

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final class LinkCollection in Drupal 8

Hierarchy

See also

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