class Token in Drupal 8

Drupal placeholder/token replacement system.

API functions for replacing placeholders in text with meaningful values.

For example: When configuring automated emails, an administrator enters standard text for the email. Variables like the title of a node and the date the email was sent can be entered as placeholders like [node:title] and [date:short]. When a Drupal module prepares to send the email, it can call the Token::replace() function, passing in the text. The token system will scan the text for placeholder tokens, give other modules an opportunity to replace them with meaningful text, then return the final product to the original module.

Tokens follow the form: [$type:$name], where $type is a general class of tokens like 'node', 'user', or 'comment' and $name is the name of a given placeholder. For example, [node:title] or [node:created:since].

In addition to raw text containing placeholders, modules may pass in an array of objects to be used when performing the replacement. The objects should be keyed by the token type they correspond to. For example:

// Load a node and a user, then replace tokens in the text.
$text = 'On [date:short], [user:name] read [node:title].';
$node = Node::load(1);
$user = User::load(1);

// [date:...] tokens use the current date automatically.
$data = array(
  'node' => $node,
  'user' => $user,
);
return Token::replace($text, $data);

Some tokens may be chained in the form of [$type:$pointer:$name], where $type is a normal token type, $pointer is a reference to another token type, and $name is the name of a given placeholder. For example, [node:author:mail]. In that example, 'author' is a pointer to the 'user' account that created the node, and 'mail' is a placeholder available for any 'user'.

Hierarchy

• class \Drupal\Core\Utility\Token

See also

Token::replace()

hook_tokens()

hook_token_info()

7 files declare their use of Token

EmailAction.php in core/lib/Drupal/Core/Action/Plugin/Action/EmailAction.php

FileUploadResource.php in core/modules/file/src/Plugin/rest/resource/FileUploadResource.php

MessageAction.php in core/lib/Drupal/Core/Action/Plugin/Action/MessageAction.php

TemporaryJsonapiFileFieldUploader.php in core/modules/jsonapi/src/Controller/TemporaryJsonapiFileFieldUploader.php

TestController.php in core/modules/system/tests/modules/token_test/src/Controller/TestController.php

... See full list

1 string reference to 'Token'

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

core/core.services.yml

1 service uses Token

token in core/core.services.yml

Drupal\Core\Utility\Token

File

core/lib/Drupal/Core/Utility/Token.php, line 60

Namespace

Drupal\Core\Utility

class Token {

  /**
   * The tag to cache token info with.
   */
  const TOKEN_INFO_CACHE_TAG = 'token_info';

  /**
   * The token cache.
   *
   * @var \Drupal\Core\Cache\CacheBackendInterface
   */
  protected $cache;

  /**
   * The language manager.
   *
   * @var \Drupal\Core\Language\LanguageManagerInterface
   */
  protected $languageManager;

  /**
   * Token definitions.
   *
   * @var array[]|null
   *   An array of token definitions, or NULL when the definitions are not set.
   *
   * @see self::setInfo()
   * @see self::getInfo()
   * @see self::resetInfo()
   */
  protected $tokenInfo;

  /**
   * The module handler service.
   *
   * @var \Drupal\Core\Extension\ModuleHandlerInterface
   */
  protected $moduleHandler;

  /**
   * The cache tags invalidator.
   *
   * @var \Drupal\Core\Cache\CacheTagsInvalidatorInterface
   */
  protected $cacheTagsInvalidator;

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

  /**
   * Constructs a new class instance.
   *
   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
   *   The module handler.
   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
   *   The token cache.
   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
   *   The language manager.
   * @param \Drupal\Core\Cache\CacheTagsInvalidatorInterface $cache_tags_invalidator
   *   The cache tags invalidator.
   * @param \Drupal\Core\Render\RendererInterface $renderer
   *   The renderer.
   */
  public function __construct(ModuleHandlerInterface $module_handler, CacheBackendInterface $cache, LanguageManagerInterface $language_manager, CacheTagsInvalidatorInterface $cache_tags_invalidator, RendererInterface $renderer) {
    $this->cache = $cache;
    $this->languageManager = $language_manager;
    $this->moduleHandler = $module_handler;
    $this->cacheTagsInvalidator = $cache_tags_invalidator;
    $this->renderer = $renderer;
  }

  /**
   * Replaces all tokens in a given string with appropriate values.
   *
   * @param string $text
   *   An HTML string containing replaceable tokens. The caller is responsible
   *   for calling \Drupal\Component\Utility\Html::escape() in case the $text
   *   was plain text.
   * @param array $data
   *   (optional) An array of keyed objects. For simple replacement scenarios
   *   'node', 'user', and others are common keys, with an accompanying node or
   *   user object being the value. Some token types, like 'site', do not require
   *   any explicit information from $data and can be replaced even if it is
   *   empty.
   * @param array $options
   *   (optional) A keyed array of settings and flags to control the token
   *   replacement process. Supported options are:
   *   - langcode: A language code to be used when generating locale-sensitive
   *     tokens.
   *   - callback: A callback function that will be used to post-process the
   *     array of token replacements after they are generated.
   *   - clear: A boolean flag indicating that tokens should be removed from the
   *     final text if no replacement value can be generated.
   * @param \Drupal\Core\Render\BubbleableMetadata|null $bubbleable_metadata
   *   (optional) An object to which static::generate() and the hooks and
   *   functions that it invokes will add their required bubbleable metadata.
   *
   *   To ensure that the metadata associated with the token replacements gets
   *   attached to the same render array that contains the token-replaced text,
   *   callers of this method are encouraged to pass in a BubbleableMetadata
   *   object and apply it to the corresponding render array. For example:
   *   @code
   *     $bubbleable_metadata = new BubbleableMetadata();
   *     $build['#markup'] = $token_service->replace('Tokens: [node:nid] [current-user:uid]', ['node' => $node], [], $bubbleable_metadata);
   *     $bubbleable_metadata->applyTo($build);
   *   @endcode
   *
   *   When the caller does not pass in a BubbleableMetadata object, this
   *   method creates a local one, and applies the collected metadata to the
   *   Renderer's currently active render context.
   *
   * @return string
   *   The token result is the entered HTML text with tokens replaced. The
   *   caller is responsible for choosing the right escaping / sanitization. If
   *   the result is intended to be used as plain text, using
   *   PlainTextOutput::renderFromHtml() is recommended. If the result is just
   *   printed as part of a template relying on Twig autoescaping is possible,
   *   otherwise for example the result can be put into #markup, in which case
   *   it would be sanitized by Xss::filterAdmin().
   */
  public function replace($text, array $data = [], array $options = [], BubbleableMetadata $bubbleable_metadata = NULL) {
    $text_tokens = $this
      ->scan($text);
    if (empty($text_tokens)) {
      return $text;
    }
    $bubbleable_metadata_is_passed_in = (bool) $bubbleable_metadata;
    $bubbleable_metadata = $bubbleable_metadata ?: new BubbleableMetadata();
    $replacements = [];
    foreach ($text_tokens as $type => $tokens) {
      $replacements += $this
        ->generate($type, $tokens, $data, $options, $bubbleable_metadata);
      if (!empty($options['clear'])) {
        $replacements += array_fill_keys($tokens, '');
      }
    }

    // Escape the tokens, unless they are explicitly markup.
    foreach ($replacements as $token => $value) {
      $replacements[$token] = $value instanceof MarkupInterface ? $value : new HtmlEscapedText($value);
    }

    // Optionally alter the list of replacement values.
    if (!empty($options['callback'])) {
      $function = $options['callback'];
      $function($replacements, $data, $options, $bubbleable_metadata);
    }
    $tokens = array_keys($replacements);
    $values = array_values($replacements);

    // If a local $bubbleable_metadata object was created, apply the metadata
    // it collected to the renderer's currently active render context.
    if (!$bubbleable_metadata_is_passed_in && $this->renderer
      ->hasRenderContext()) {
      $build = [];
      $bubbleable_metadata
        ->applyTo($build);
      $this->renderer
        ->render($build);
    }
    return str_replace($tokens, $values, $text);
  }

  /**
   * Builds a list of all token-like patterns that appear in the text.
   *
   * @param string $text
   *   The text to be scanned for possible tokens.
   *
   * @return array
   *   An associative array of discovered tokens, grouped by type.
   */
  public function scan($text) {

    // Matches tokens with the following pattern: [$type:$name]
    // $type and $name may not contain [ ] characters.
    // $type may not contain : or whitespace characters, but $name may.
    preg_match_all('/
      \\[             # [ - pattern start
      ([^\\s\\[\\]:]+)  # match $type not containing whitespace : [ or ]
      :              # : - separator
      ([^\\[\\]]+)     # match $name not containing [ or ]
      \\]             # ] - pattern end
      /x', $text, $matches);
    $types = $matches[1];
    $tokens = $matches[2];

    // Iterate through the matches, building an associative array containing
    // $tokens grouped by $types, pointing to the version of the token found in
    // the source text. For example, $results['node']['title'] = '[node:title]';
    $results = [];
    for ($i = 0; $i < count($tokens); $i++) {
      $results[$types[$i]][$tokens[$i]] = $matches[0][$i];
    }
    return $results;
  }

  /**
   * Generates replacement values for a list of tokens.
   *
   * @param string $type
   *   The type of token being replaced. 'node', 'user', and 'date' are common.
   * @param array $tokens
   *   An array of tokens to be replaced, keyed by the literal text of the token
   *   as it appeared in the source text.
   * @param array $data
   *   An array of keyed objects. For simple replacement scenarios: 'node',
   *   'user', and others are common keys, with an accompanying node or user
   *   object being the value. Some token types, like 'site', do not require
   *   any explicit information from $data and can be replaced even if it is
   *   empty.
   * @param array $options
   *   A keyed array of settings and flags to control the token replacement
   *   process. Supported options are:
   *   - langcode: A language code to be used when generating locale-sensitive
   *     tokens.
   *   - callback: A callback function that will be used to post-process the
   *     array of token replacements after they are generated. Can be used when
   *     modules require special formatting of token text, for example URL
   *     encoding or truncation to a specific length.
   * @param \Drupal\Core\Render\BubbleableMetadata $bubbleable_metadata
   *   The bubbleable metadata. This is passed to the token replacement
   *   implementations so that they can attach their metadata.
   *
   * @return array
   *   An associative array of replacement values, keyed by the original 'raw'
   *   tokens that were found in the source text. For example:
   *   $results['[node:title]'] = 'My new node';
   *
   * @see hook_tokens()
   * @see hook_tokens_alter()
   */
  public function generate($type, array $tokens, array $data, array $options, BubbleableMetadata $bubbleable_metadata) {
    foreach ($data as $object) {
      if ($object instanceof CacheableDependencyInterface || $object instanceof AttachmentsInterface) {
        $bubbleable_metadata
          ->addCacheableDependency($object);
      }
    }
    $replacements = $this->moduleHandler
      ->invokeAll('tokens', [
      $type,
      $tokens,
      $data,
      $options,
      $bubbleable_metadata,
    ]);

    // Allow other modules to alter the replacements.
    $context = [
      'type' => $type,
      'tokens' => $tokens,
      'data' => $data,
      'options' => $options,
    ];
    $this->moduleHandler
      ->alter('tokens', $replacements, $context, $bubbleable_metadata);
    return $replacements;
  }

  /**
   * Returns a list of tokens that begin with a specific prefix.
   *
   * Used to extract a group of 'chained' tokens (such as [node:author:name])
   * from the full list of tokens found in text. For example:
   * @code
   *   $data = array(
   *     'author:name' => '[node:author:name]',
   *     'title'       => '[node:title]',
   *     'created'     => '[node:created]',
   *   );
   *   $results = Token::findWithPrefix($data, 'author');
   *   $results == array('name' => '[node:author:name]');
   * @endcode
   *
   * @param array $tokens
   *   A keyed array of tokens, and their original raw form in the source text.
   * @param string $prefix
   *   A textual string to be matched at the beginning of the token.
   * @param string $delimiter
   *   (optional) A string containing the character that separates the prefix from
   *   the rest of the token. Defaults to ':'.
   *
   * @return array
   *   An associative array of discovered tokens, with the prefix and delimiter
   *   stripped from the key.
   */
  public function findWithPrefix(array $tokens, $prefix, $delimiter = ':') {
    $results = [];
    foreach ($tokens as $token => $raw) {
      $parts = explode($delimiter, $token, 2);
      if (count($parts) == 2 && $parts[0] == $prefix) {
        $results[$parts[1]] = $raw;
      }
    }
    return $results;
  }

  /**
   * Returns metadata describing supported tokens.
   *
   * The metadata array contains token type, name, and description data as well
   * as an optional pointer indicating that the token chains to another set of
   * tokens.
   *
   * @return array
   *   An associative array of token information, grouped by token type. The
   *   array structure is identical to that of hook_token_info().
   *
   * @see hook_token_info()
   */
  public function getInfo() {
    if (is_null($this->tokenInfo)) {
      $cache_id = 'token_info:' . $this->languageManager
        ->getCurrentLanguage(LanguageInterface::TYPE_CONTENT)
        ->getId();
      $cache = $this->cache
        ->get($cache_id);
      if ($cache) {
        $this->tokenInfo = $cache->data;
      }
      else {
        $this->tokenInfo = $this->moduleHandler
          ->invokeAll('token_info');
        $this->moduleHandler
          ->alter('token_info', $this->tokenInfo);
        $this->cache
          ->set($cache_id, $this->tokenInfo, CacheBackendInterface::CACHE_PERMANENT, [
          static::TOKEN_INFO_CACHE_TAG,
        ]);
      }
    }
    return $this->tokenInfo;
  }

  /**
   * Sets metadata describing supported tokens.
   *
   * @param array $tokens
   *   Token metadata that has an identical structure to the return value of
   *   hook_token_info().
   *
   * @see hook_token_info()
   */
  public function setInfo(array $tokens) {
    $this->tokenInfo = $tokens;
  }

  /**
   * Resets metadata describing supported tokens.
   */
  public function resetInfo() {
    $this->tokenInfo = NULL;
    $this->cacheTagsInvalidator
      ->invalidateTags([
      static::TOKEN_INFO_CACHE_TAG,
    ]);
  }

}

Members

Name	Modifiers	Type	Description	Overrides
Token::$cache	protected	property	The token cache.
Token::$cacheTagsInvalidator	protected	property	The cache tags invalidator.
Token::$languageManager	protected	property	The language manager.
Token::$moduleHandler	protected	property	The module handler service.
Token::$renderer	protected	property	The renderer.
Token::$tokenInfo	protected	property	Token definitions.
Token::findWithPrefix	public	function	Returns a list of tokens that begin with a specific prefix.
Token::generate	public	function	Generates replacement values for a list of tokens.
Token::getInfo	public	function	Returns metadata describing supported tokens.
Token::replace	public	function	Replaces all tokens in a given string with appropriate values.
Token::resetInfo	public	function	Resets metadata describing supported tokens.
Token::scan	public	function	Builds a list of all token-like patterns that appear in the text.
Token::setInfo	public	function	Sets metadata describing supported tokens.
Token::TOKEN_INFO_CACHE_TAG		constant	The tag to cache token info with.
Token::__construct	public	function	Constructs a new class instance.