Definition of Drupal\Core\Utility\Token.
<?php
/**
* @file
* Definition of Drupal\Core\Utility\Token.
*/
namespace Drupal\Core\Utility;
use Drupal\Core\Extension\ModuleHandlerInterface;
/**
* 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:
*
* @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()
*/
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;
}
}