class Token

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

Expanded class hierarchy of Token

See also

Token::replace()

hook_tokens()

hook_token_info()

2 files declare their use of Token
EmailAction.php in drupal/core/modules/action/lib/Drupal/action/Plugin/Action/EmailAction.php
Contains \Drupal\action\Plugin\Action\EmailAction.
MessageAction.php in drupal/core/modules/action/lib/Drupal/action/Plugin/Action/MessageAction.php
Contains \Drupal\action\Plugin\Action\MessageAction.
1 string reference to 'Token'
core.services.yml in drupal/core/core.services.yml
drupal/core/core.services.yml
1 service uses Token
token in drupal/core/core.services.yml
Drupal\Core\Utility\Token

File

drupal/core/lib/Drupal/Core/Utility/Token.php, line 55
Definition of Drupal\Core\Utility\Token.

Namespace

Drupal\Core\Utility
View source
class Token {

  /**
   * 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;

  /**
   * Constructor.
   *
   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
   */
  public function __construct(ModuleHandlerInterface $module_handler) {
    $this->moduleHandler = $module_handler;
  }

  /**
   * Replaces all tokens in a given string with appropriate values.
   *
   * @param string $text
   *   A string potentially containing replaceable tokens.
   * @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 $options
   *   (optional) A keyed array of settings and flags to control the token
   *   replacement process. Supported options are:
   *   - langcode: A language code to be used when generating locale-sensitive
   *     tokens.
   *   - callback: A callback function that will be used to post-process the
   *     array of token replacements after they are generated. For example, a
   *     module using tokens in a text-only email might provide a callback to
   *     strip HTML entities from token values before they are inserted into the
   *     final text.
   *   - clear: A boolean flag indicating that tokens should be removed from the
   *     final text if no replacement value can be generated.
   *   - sanitize: A boolean flag indicating that tokens should be sanitized for
   *     display to a web browser. Defaults to TRUE. Developers who set this
   *     option to FALSE assume responsibility for running filter_xss(),
   *     check_plain() or other appropriate scrubbing functions before displaying
   *     data to users.
   *
   * @return string
   *   Text with tokens replaced.
   */
  public function replace($text, array $data = array(), array $options = array()) {
    $text_tokens = $this
      ->scan($text);
    if (empty($text_tokens)) {
      return $text;
    }
    $replacements = array();
    foreach ($text_tokens as $type => $tokens) {
      $replacements += $this
        ->generate($type, $tokens, $data, $options);
      if (!empty($options['clear'])) {
        $replacements += array_fill_keys($tokens, '');
      }
    }

    // Optionally alter the list of replacement values.
    if (!empty($options['callback'])) {
      $function = $options['callback'];
      $function($replacements, $data, $options);
    }
    $tokens = array_keys($replacements);
    $values = array_values($replacements);
    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]';
    $results = array();
    for ($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
   *   (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. Can be used when
   *     modules require special formatting of token text, for example URL
   *     encoding or truncation to a specific length.
   *   - sanitize: A boolean flag indicating that tokens should be sanitized for
   *     display to a web browser. Developers who set this option to FALSE assume
   *     responsibility for running filter_xss(), check_plain() or other
   *     appropriate scrubbing functions before displaying data to users.
   *
   * @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(), array $options = array()) {
    $options += array(
      'sanitize' => TRUE,
    );
    $replacements = $this->moduleHandler
      ->invokeAll('tokens', array(
      $type,
      $tokens,
      $data,
      $options,
    ));

    // Allow other modules to alter the replacements.
    $context = array(
      'type' => $type,
      'tokens' => $tokens,
      'data' => $data,
      'options' => $options,
    );
    $this->moduleHandler
      ->alter('tokens', $replacements, $context);
    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 = ':') {
    $results = array();
    foreach ($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)) {
      $this->tokenInfo = $this->moduleHandler
        ->invokeAll('token_info');
      $this->moduleHandler
        ->alter('token_info', $this->tokenInfo);
    }
    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;
  }

}

Members

Namesort descending Modifiers Type Description Overrides
Token::$moduleHandler protected property The module handler service.
Token::$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::__construct public function Constructor.