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Drupal example source code file (token.inc)

This example Drupal source code file (token.inc) is included in the DevDaily.com "Drupal Source Code Warehouse" project. The intent of this project is to help you "Learn Drupal by Example".

PHP - Drupal tags/keywords

array, data, foreach, function, matches, options, parts, php, replacements, results, return, text, tokens, type

The token.inc Drupal example source code

<?php
// $Id: token.inc,v 1.10 2010/10/18 01:13:07 dries Exp $

/**
 * @file
 * Drupal placeholder/token replacement system.
 *
 * Provides a set of extensible 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].
 *
 * 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:
 *
 * @code
 * // 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, $data);
 * @endcode
 *
 * Some tokens may be chained in the form of [$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'.
 *
 * @see token_replace()
 * @see hook_tokens()
 * @see hook_token_info()
 */

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

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

  $tokens = array_keys($replacements);
  $values = array_values($replacements);

  return str_replace($tokens, $values, $text);
}

/**
 * Build a list of all token-like patterns that appear in the text.
 *
 * @param $text
 *   The text to be scanned for possible tokens.
 * @return
 *   An associative array of discovered tokens, grouped by type.
 */
function token_scan($text) {
  // Matches tokens with the following pattern: [$type:$token]
  // $type and $token may not contain white spaces.
  preg_match_all('/\[([^\s\]:]*):([^\s\]]*)\]/', $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;
}

/**
 * Generate replacement values for a list of tokens.
 *
 * @param $type
 *   The type of token being replaced. 'node', 'user', and 'date' are common.
 * @param $tokens
 *   An array of tokens to be replaced, keyed by the literal text of the token
 *   as it appeared in the source text.
 * @param $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 $options
 *   (optional) A keyed array of settings and flags to control the token
 *   replacement process. Supported options are:
 *   - 'language' A language object 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
 *   An associative array of replacement values, keyed by the original 'raw'
 *   tokens that were found in the source text. For example:
 *   $results['[node:title]'] = 'My new node';
 *
 * @see hook_tokens()
 * @see hook_tokens_alter()
 */
function token_generate($type, array $tokens, array $data = array(), array $options = array()) {
  $options += array('sanitize' => TRUE);
  $replacements = module_invoke_all('tokens', $type, $tokens, $data, $options);

  // Allow other modules to alter the replacements.
  $context = array(
    'type' => $type,
    'tokens' => $tokens,
    'data' => $data,
    'options' => $options,
  );
  drupal_alter('tokens', $replacements, $context);

  return $replacements;
}

/**
 * Given a list of tokens, return those 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:author:name]',
 *   );
 *   $results = token_find_with_prefix($data, 'author');
 *   $results == array('name' => '[node:author:name]');
 * @endcode
 *
 * @param $tokens
 *   A keyed array of tokens, and their original raw form in the source text.
 * @param $prefix
 *   A textual string to be matched at the beginning of the token.
 * @param $delimiter
 *   An optional string containing the character that separates the prefix from
 *   the rest of the token. Defaults to ':'.
 * @return
 *   An associative array of discovered tokens, with the prefix and delimiter
 *   stripped from the key.
 */
function token_find_with_prefix(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.
 * For example:
 * @code
 *   $data['types']['node'] = array(
 *     'name' => t('Nodes'),
 *     'description' => t('Tokens related to node objects.'),
 *   );
 *   $data['tokens']['node']['title'] = array(
 *     'name' => t('Title'),
 *     'description' => t('The title of the current node.'),
 *   );
 *   $data['tokens']['node']['author'] = array(
 *     'name' => t('Author'),
 *     'description' => t('The author of the current node.'),
 *     'type' => 'user',
 *   );
 * @endcode
 * @return
 *   An associative array of token information, grouped by token type.
 */
function token_info() {
  $data = &drupal_static(__FUNCTION__);
  if (!isset($data)) {
    $data = module_invoke_all('token_info');
    drupal_alter('token_info', $data);
  }
  return $data;
}

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