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potx.inc in Translation template extractor 7.3

Extraction API used by the web and command line interface.

This include file implements the default string and file version storage as well as formatting of POT files for web download or file system level creation. The strings, versions and file contents are handled with global variables to reduce the possible memory overhead and API clutter of passing them around. Custom string and version saving functions can be implemented to use the functionality provided here as an API for Drupal code to translatable string conversion.

For a module using potx as an extraction API, but providing more sophisticated functionality on top of it, look into the 'Localization server' module: http://drupal.org/project/l10n_server

File

potx.inc
View source
<?php

/**
 * @file
 *   Extraction API used by the web and command line interface.
 *
 *   This include file implements the default string and file version
 *   storage as well as formatting of POT files for web download or
 *   file system level creation. The strings, versions and file contents
 *   are handled with global variables to reduce the possible memory overhead
 *   and API clutter of passing them around. Custom string and version saving
 *   functions can be implemented to use the functionality provided here as an
 *   API for Drupal code to translatable string conversion.
 *
 *   For a module using potx as an extraction API, but providing more
 *   sophisticated functionality on top of it, look into the
 *   'Localization server' module: http://drupal.org/project/l10n_server
 */

/**
 * Use Twig and the Symfony YAML parser, found in the vendor directory.
 */
set_include_path(get_include_path() . PATH_SEPARATOR . __DIR__ . '/vendor');
spl_autoload_register(function ($c) {
  @(include preg_replace('#\\\\|_(?!.*\\\\)#', '/', $c) . '.php');
});
use Symfony\Component\Yaml\Yaml;
use Symfony\Component\Yaml\Exception\ParseException;

/**
 * The current Drupal major API verion.
 *
 * This should be the only difference between different branches of potx.inc
 */
define('POTX_API_CURRENT', 7);

/**
 * Silence status reports.
 */
define('POTX_STATUS_SILENT', 0);

/**
 * Drupal message based status reports.
 */
define('POTX_STATUS_MESSAGE', 1);

/**
 * Command line status reporting.
 *
 * Status goes to standard output, errors to standard error.
 */
define('POTX_STATUS_CLI', 2);

/**
 * Structured array status logging.
 *
 * Useful for coder review status reporting.
 */
define('POTX_STATUS_STRUCTURED', 3);

/**
 * Core parsing mode:
 *  - .info files folded into general.pot
 *  - separate files generated for modules
 */
define('POTX_BUILD_CORE', 0);

/**
 * Multiple files mode:
 *  - .info files folded into their module pot files
 *  - separate files generated for modules
 */
define('POTX_BUILD_MULTIPLE', 1);

/**
 * Single file mode:
 *  - all files folded into one pot file
 */
define('POTX_BUILD_SINGLE', 2);

/**
 * Save string to both installer and runtime collection.
 */
define('POTX_STRING_BOTH', 0);

/**
 * Save string to installer collection only.
 */
define('POTX_STRING_INSTALLER', 1);

/**
 * Save string to runtime collection only.
 */
define('POTX_STRING_RUNTIME', 2);

/**
 * Parse source files in Drupal 5.x format.
 */
define('POTX_API_5', 5);

/**
 * Parse source files in Drupal 6.x format.
 *
 * Changes since 5.x documented at http://drupal.org/node/114774
 */
define('POTX_API_6', 6);

/**
 * Parse source files in Drupal 7.x format.
 *
 * Changes since 6.x documented at http://drupal.org/node/224333
 */
define('POTX_API_7', 7);

/**
 * Parse source files in Drupal 8.x format.
 *
 * Changes since 7.x documented at
 * http://drupal.org/list-changes/drupal?to_branch=8.x
 */
define('POTX_API_8', 8);

/**
 * When no context is used. Makes it easy to look these up.
 */
define('POTX_CONTEXT_NONE', NULL);

/**
 * When there was a context identification error.
 */
define('POTX_CONTEXT_ERROR', FALSE);

/**
 * Regular expression pattern used to localize JavaScript strings.
 */
define('POTX_JS_STRING', '(?:(?:\'(?:\\\\\'|[^\'])*\'|"(?:\\\\"|[^"])*")(?:\\s*\\+\\s*)?)+');

/**
 * Regular expression pattern used to match simple JS object literal.
 *
 * This pattern matches a basic JS object, but will fail on an object with
 * nested objects. Used in JS file parsing for string arg processing.
 */
define('POTX_JS_OBJECT', '\\{.*?\\}');

/**
 * Regular expression to match an object containing a key 'context'.
 *
 * Pattern to match a JS object containing a 'context key' with a string value,
 * which is captured. Will fail if there are nested objects.
 */
define('POTX_JS_OBJECT_CONTEXT', '
  \\{              # match object literal start
  .*?             # match anything, non-greedy
  (?:             # match a form of "context"
    \'context\'
    |
    "context"
    |
    context
  )
  \\s*:\\s*         # match key-value separator ":"
  (' . POTX_JS_STRING . ')  # match context string
  .*?             # match anything, non-greedy
  \\}              # match end of object literal
');

/**
 * Process a file and put extracted information to the given parameters.
 *
 * @param $file_path
 *   Comlete path to file to process.
 * @param $strip_prefix
 *   An integer denoting the number of chars to strip from filepath for output.
 * @param $save_callback
 *   Callback function to use to save the collected strings.
 * @param $version_callback
 *   Callback function to use to save collected version numbers.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_process_file($file_path, $strip_prefix = 0, $save_callback = '_potx_save_string', $version_callback = '_potx_save_version', $api_version = POTX_API_CURRENT) {
  global $_potx_tokens, $_potx_lookup;

  // Figure out the basename and extension to select extraction method.
  $basename = basename($file_path);
  $name_parts = pathinfo($basename);

  // Always grab the CVS version number from the code
  $code = file_get_contents($file_path);
  $file_name = $strip_prefix > 0 ? substr($file_path, $strip_prefix) : $file_path;
  _potx_find_version_number($code, $file_name, $version_callback);

  // The .info files are not PHP code, no need to tokenize.
  if ($name_parts['extension'] == 'info' && $api_version < POTX_API_8) {
    _potx_find_info_file_strings($file_path, $file_name, $save_callback, $api_version);
    return;
  }
  elseif ($name_parts['extension'] == 'yml' && $api_version > POTX_API_7) {
    _potx_parse_yaml_file($code, $file_name, $file_path, $save_callback);
  }
  elseif ($name_parts['extension'] == 'js' && $api_version > POTX_API_5) {

    // @todo: D7 context support.
    _potx_parse_js_file($code, $file_name, $save_callback);
  }
  elseif ($name_parts['extension'] == 'twig' && $api_version > POTX_API_7) {
    _potx_parse_twig_file($code, $file_name, $save_callback);
  }
  $constraint_extract = FALSE;
  if (substr($name_parts['filename'], -10) == 'Constraint' && $api_version > POTX_API_7) {
    $constraint_extract = TRUE;
  }

  // Extract raw PHP language tokens.
  $raw_tokens = token_get_all($code);
  unset($code);

  // Remove whitespace and possible HTML (the later in templates for example),
  // count line numbers so we can include them in the output.
  $_potx_tokens = array();
  $_potx_lookup = array();
  $token_number = 0;
  $line_number = 1;
  foreach ($raw_tokens as $token) {
    if (!is_array($token) || $token[0] != T_WHITESPACE && $token[0] != T_INLINE_HTML) {
      if (is_array($token)) {
        $token[] = $line_number;
        $constraint_match = $constraint_extract && $token[0] == T_VARIABLE && strlen($token[1]) >= 7 && substr_compare($token[1], 'message', -7, 7, true) === 0;

        // Fill array for finding token offsets quickly.
        if (in_array($token[0], array(
          T_STRING,
          T_DOC_COMMENT,
        )) || $token[0] == T_VARIABLE && $token[1] == '$t' || $constraint_match || $token[0] == T_CONSTANT_ENCAPSED_STRING && ($token[1] == "'#template'" || $token[1] == '"#template"')) {

          // Give doc comments a specific key because their content varies.
          $key = $token[0] == T_DOC_COMMENT ? 'T_DOC_COMMENT' : ($constraint_match ? 'T_POTX_CONSTRAINT' : $token[1]);

          // Normalise "#template" token to support both single-quoted and double-quoted #template keys.
          if ($key == '"#template"') {
            $key = "'#template'";
          }
          if (!isset($_potx_lookup[$key])) {
            $_potx_lookup[$key] = array();
          }
          $_potx_lookup[$key][] = $token_number;
        }
      }
      $_potx_tokens[] = $token;
      $token_number++;
    }

    // Collect line numbers.
    if (is_array($token)) {
      $line_number += count(explode("\n", $token[1])) - 1;
    }
    else {
      $line_number += count(explode("\n", $token)) - 1;
    }
  }
  unset($raw_tokens);

  // Regular t() calls with different usages.
  if ($api_version > POTX_API_6) {

    // Drupal 7 onwards supports context on t().
    _potx_find_t_calls_with_context($file_name, $save_callback);
    if ($api_version < POTX_API_8) {

      // st() and $t() are supported up to Drupal 7.
      _potx_find_t_calls_with_context($file_name, $save_callback, '$t', POTX_STRING_BOTH);
      _potx_find_t_calls_with_context($file_name, $save_callback, 'st', POTX_STRING_INSTALLER);
    }
    else {

      // TranslatableMarkup (and deprecated TranslationWrapper) added in Drupal 8.
      _potx_find_t_calls_with_context($file_name, $save_callback, 'TranslatableMarkup');
      _potx_find_t_calls_with_context($file_name, $save_callback, 'TranslationWrapper');
    }
  }
  else {

    // Context-less API up to Drupal 6.
    _potx_find_t_calls($file_name, $save_callback);
    _potx_find_t_calls($file_name, $save_callback, '$t', POTX_STRING_BOTH);
    _potx_find_t_calls($file_name, $save_callback, 'st', POTX_STRING_INSTALLER);
  }
  if ($api_version < POTX_API_8) {

    // This does not support context even in Drupal 7.
    _potx_find_t_calls($file_name, $save_callback, '_locale_import_message', POTX_STRING_BOTH);
  }

  // dt() in drush does not support context either.
  _potx_find_t_calls($file_name, $save_callback, 'dt');
  if ($api_version > POTX_API_5) {

    // Watchdog calls have both of their arguments translated from Drupal 6.x.
    if ($api_version < POTX_API_8) {
      _potx_find_watchdog_calls($file_name, $save_callback);
    }
    if ($api_version > POTX_API_7) {

      // Logging calls may use a colorful set of methods now.
      _potx_find_t_calls($file_name, $save_callback, 'debug');
      _potx_find_t_calls($file_name, $save_callback, 'info');
      _potx_find_t_calls($file_name, $save_callback, 'notice');
      _potx_find_t_calls($file_name, $save_callback, 'warning');
      _potx_find_t_calls($file_name, $save_callback, 'error');
      _potx_find_t_calls($file_name, $save_callback, 'critical');
      _potx_find_t_calls($file_name, $save_callback, 'alert');
      _potx_find_t_calls($file_name, $save_callback, 'emergency');
      _potx_find_log_calls($file_name, $save_callback);
    }
  }
  else {

    // Watchdog calls only have their first argument translated in Drupal 5.x
    // and before.
    _potx_find_t_calls($file_name, $save_callback, 'watchdog');
  }

  // Plurals need unique parsing.
  if ($api_version < POTX_API_8) {

    // format_plural() is removed in Drupal 8.
    _potx_find_format_plural_calls($file_name, $save_callback, 'format_plural', $api_version);
  }

  // Support for formatPlural() calls in Drupal 8+.
  if ($api_version > POTX_API_7) {
    _potx_find_format_plural_calls($file_name, $save_callback, 'formatPlural', $api_version);
    _potx_find_format_plural_calls($file_name, $save_callback, 'PluralTranslatableMarkup', $api_version);
  }
  if ($name_parts['extension'] == 'module') {
    if ($api_version < POTX_API_7) {
      _potx_find_perm_hook($file_name, $name_parts['filename'], $save_callback);
    }
    if ($api_version > POTX_API_5) {

      // @todo: if tabs are not defined on the menu hook anymore, exclude this for 8.
      _potx_find_menu_hooks($file_name, $name_parts['filename'], $save_callback);
    }
  }

  // Support @Translation annotation (in doc comments) on Drupal 8+.
  if ($api_version > POTX_API_7) {
    _potx_find_translation_annotations($file_name, $save_callback);
  }
  if ($constraint_extract) {
    _potx_find_constraint_messages($file_name, $save_callback);
  }
  if ($api_version > POTX_API_7) {
    _potx_process_inline_templates($file_name, $save_callback);
  }

  // Special handling of some Drupal core files.
  if ($api_version < POTX_API_8 && ($basename == 'locale.inc' && $api_version < POTX_API_7 || $basename == 'iso.inc')) {
    _potx_find_language_names($file_name, $save_callback, $api_version);
  }
  elseif ($api_version > POTX_API_7 && $basename == 'LanguageManager.php') {
    _potx_find_language_names($file_name, $save_callback, $api_version);
  }
  elseif ($basename == 'locale.module') {

    // Applies to all Drupal versions, yay!
    _potx_add_date_strings($file_name, $save_callback, $api_version);
  }
  elseif ($basename == 'common.inc') {

    // Applies to all Drupal versions, yay!
    _potx_add_format_interval_strings($file_name, $save_callback, $api_version);
  }
  elseif ($basename == 'system.module') {

    // Applies to all Drupal versions, yay!
    _potx_add_default_region_names($file_name, $save_callback, $api_version);
  }
  elseif ($basename == 'user.module' && $api_version < POTX_API_8) {

    // Save default user role names (up to Drupal 7).
    $save_callback('anonymous user', POTX_CONTEXT_NONE, $file_name);
    $save_callback('authenticated user', POTX_CONTEXT_NONE, $file_name);
    if ($api_version > POTX_API_6) {

      // Administator role is included by default from Drupal 7.
      $save_callback('administrator', POTX_CONTEXT_NONE, $file_name);
    }
  }
}

/**
 * Executes tasks that need to happen after all the files have been processed.
 *
 * @param string $save_callback
 * @param int $api_version
 */
function potx_finish_processing($save_callback = '_potx_save_string', $api_version = POTX_API_CURRENT) {
  global $yaml_translation_patterns;
  global $_potx_module_metadata;
  global $potx_callbacks;
  if ($api_version > POTX_API_7) {
    foreach ($_potx_module_metadata as $module_name => $module_metadata) {
      $potx_callbacks['store_module_metadata']($module_name, $module_metadata);
    }

    // Parsing shipped configuration has to happen after processing all schemas.
    _potx_parse_shipped_configuration($save_callback, $api_version);

    // Clear yaml translation patterns, so translation patterns for a module
    // won't be used for extracting translatable strings for another module.
    $yaml_translation_patterns = NULL;
  }
}

/**
 * Creates complete file strings with _potx_store()
 *
 * @param $string_mode
 *   Strings to generate files for: POTX_STRING_RUNTIME or POTX_STRING_INSTALLER.
 * @param $build_mode
 *   Storage mode used: single, multiple or core
 * @param $force_name
 *   Forces a given file name to get used, if single mode is on, without extension
 * @param $save_callback
 *   Callback used to save strings previously.
 * @param $version_callback
 *   Callback used to save versions previously.
 * @param $header_callback
 *   Callback to invoke to get the POT header.
 * @param $template_export_langcode
 *   Language code if the template should have language dependent content
 *   (like plural formulas and language name) included.
 * @param $translation_export_langcode
 *   Language code if translations should also be exported.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_build_files($string_mode = POTX_STRING_RUNTIME, $build_mode = POTX_BUILD_SINGLE, $force_name = 'general', $save_callback = '_potx_save_string', $version_callback = '_potx_save_version', $header_callback = '_potx_get_header', $template_export_langcode = NULL, $translation_export_langcode = NULL, $api_version = POTX_API_CURRENT) {
  global $_potx_store;

  // Get strings and versions by reference.
  $strings = $save_callback(NULL, NULL, NULL, 0, $string_mode);
  $versions = $version_callback();

  // We might not have any string recorded in this string mode.
  if (!is_array($strings)) {
    return;
  }
  foreach ($strings as $string => $string_info) {
    foreach ($string_info as $context => $file_info) {

      // Build a compact list of files this string occured in.
      $occured = $file_list = array();

      // Look for strings appearing in multiple directories (ie.
      // different subprojects). So we can include them in general.pot.
      $names = array_keys($file_info);
      $last_location = dirname(array_shift($names));
      $multiple_locations = FALSE;
      foreach ($file_info as $file => $lines) {
        $occured[] = "{$file}:" . join(';', $lines);
        if (isset($versions[$file])) {
          $file_list[] = $versions[$file];
        }
        if (dirname($file) != $last_location) {
          $multiple_locations = TRUE;
        }
        $last_location = dirname($file);
      }

      // Mark duplicate strings (both translated in the app and in the installer).
      $comment = join(" ", $occured);
      if (strpos($comment, '(dup)') !== FALSE) {
        $comment = '(duplicate) ' . str_replace('(dup)', '', $comment);
      }
      $output = "#: {$comment}\n";
      if ($build_mode == POTX_BUILD_SINGLE) {

        // File name forcing in single mode.
        $file_name = $force_name;
      }
      elseif (strpos($comment, '.info')) {

        // Store .info file strings either in general.pot or the module pot file,
        // depending on the mode used.
        $file_name = $build_mode == POTX_BUILD_CORE ? 'general' : str_replace('.info', '.module', $file_name);
      }
      elseif ($multiple_locations) {

        // Else if occured more than once, store in general.pot.
        $file_name = 'general';
      }
      else {

        // Fold multiple files in the same folder into one.
        if (empty($last_location) || $last_location == '.') {
          $file_name = 'root';
        }
        else {
          $file_name = str_replace('/', '-', $last_location);
        }
      }
      if (strpos($string, "\0") !== FALSE) {

        // Plural strings have a null byte delimited format.
        list($singular, $plural) = explode("\0", $string);
        if (!empty($context)) {
          $output .= "msgctxt \"{$context}\"\n";
        }
        $output .= "msgid \"{$singular}\"\n";
        $output .= "msgid_plural \"{$plural}\"\n";
        if (isset($translation_export_langcode)) {
          $output .= _potx_translation_export($translation_export_langcode, $singular, $plural, $api_version);
        }
        else {
          $output .= "msgstr[0] \"\"\n";
          $output .= "msgstr[1] \"\"\n";
        }
      }
      else {

        // Simple strings.
        if (!empty($context)) {
          $output .= "msgctxt \"{$context}\"\n";
        }
        $output .= "msgid \"{$string}\"\n";
        if (isset($translation_export_langcode)) {
          $output .= _potx_translation_export($translation_export_langcode, $string, NULL, $api_version);
        }
        else {
          $output .= "msgstr \"\"\n";
        }
      }
      $output .= "\n";

      // Store the generated output in the given file storage.
      if (!isset($_potx_store[$file_name])) {
        $_potx_store[$file_name] = array(
          'header' => $header_callback($file_name, $template_export_langcode, $api_version),
          'sources' => $file_list,
          'strings' => $output,
          'count' => 1,
        );
      }
      else {

        // Maintain a list of unique file names.
        $_potx_store[$file_name]['sources'] = array_unique(array_merge($_potx_store[$file_name]['sources'], $file_list));
        $_potx_store[$file_name]['strings'] .= $output;
        $_potx_store[$file_name]['count'] += 1;
      }
    }
  }
}

/**
 * Export translations with a specific language.
 *
 * @param $translation_export_langcode
 *   Language code if translations should also be exported.
 * @param $string
 *   String or singular version if $plural was provided.
 * @param $plural
 *   Plural version of singular string.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_translation_export($translation_export_langcode, $string, $plural = NULL, $api_version = POTX_API_CURRENT) {
  include_once 'includes/locale.inc';

  // Stip out slash escapes.
  $string = stripcslashes($string);

  // Column and table name changed between versions.
  $language_column = $api_version > POTX_API_5 ? 'language' : 'locale';
  $language_table = $api_version > POTX_API_5 ? 'languages' : 'locales_meta';
  if (!isset($plural)) {

    // Single string to look translation up for.
    if ($translation = db_query("SELECT t.translation FROM {locales_source} s LEFT JOIN {locales_target} t ON t.lid = s.lid WHERE s.source = :source AND t.{$language_column} = :langcode", array(
      ':source' => $string,
      ':langcode' => $translation_export_langcode,
    ))
      ->fetchField()) {
      return 'msgstr ' . _locale_export_string($translation);
    }
    return "msgstr \"\"\n";
  }
  else {

    // String with plural variants. Fill up source string array first.
    $plural = stripcslashes($plural);
    $strings = array();
    $number_of_plurals = db_query('SELECT plurals FROM {' . $language_table . "} WHERE {$language_column} = :langcode", array(
      ':langcode' => $translation_export_langcode,
    ))
      ->fetchField();
    $plural_index = 0;
    while ($plural_index < $number_of_plurals) {
      if ($plural_index == 0) {

        // Add the singular version.
        $strings[] = $string;
      }
      elseif ($plural_index == 1) {

        // Only add plural version if required.
        $strings[] = $plural;
      }
      else {

        // More plural versions only if required, with the lookup source
        // string modified as imported into the database.
        $strings[] = str_replace('@count', '@count[' . $plural_index . ']', $plural);
      }
      $plural_index++;
    }
    $output = '';
    if (count($strings)) {

      // Source string array was done, so export translations.
      foreach ($strings as $index => $string) {
        if ($translation = db_query("SELECT t.translation FROM {locales_source} s LEFT JOIN {locales_target} t ON t.lid = s.lid WHERE s.source = :source AND t.{$language_column} = :langcode", array(
          ':source' => $string,
          ':langcode' => $translation_export_langcode,
        ))
          ->fetchField()) {
          $output .= 'msgstr[' . $index . '] ' . _locale_export_string(_locale_export_remove_plural($translation));
        }
        else {
          $output .= "msgstr[" . $index . "] \"\"\n";
        }
      }
    }
    else {

      // No plural information was recorded, so export empty placeholders.
      $output .= "msgstr[0] \"\"\n";
      $output .= "msgstr[1] \"\"\n";
    }
    return $output;
  }
}

/**
 * Returns a header generated for a given file
 *
 * @param $file
 *   Name of POT file to generate header for
 * @param $template_export_langcode
 *   Language code if the template should have language dependent content
 *   (like plural formulas and language name) included.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_get_header($file, $template_export_langcode = NULL, $api_version = POTX_API_CURRENT) {

  // We only have language to use if we should export with that langcode.
  $language = NULL;
  if (isset($template_export_langcode)) {
    $language = db_query($api_version > POTX_API_5 ? "SELECT language, name, plurals, formula FROM {languages} WHERE language = :langcode" : "SELECT locale, name, plurals, formula FROM {locales_meta} WHERE locale = :langcode", array(
      ':langcode' => $template_export_langcode,
    ))
      ->fetchObject();
  }
  $output = '# $' . 'Id' . '$' . "\n";
  $output .= "#\n";
  $output .= '# ' . (isset($language) ? $language->name : 'LANGUAGE') . ' translation of Drupal (' . $file . ")\n";
  $output .= "# Copyright YEAR NAME <EMAIL@ADDRESS>\n";
  $output .= "# --VERSIONS--\n";
  $output .= "#\n";
  $output .= "#, fuzzy\n";
  $output .= "msgid \"\"\n";
  $output .= "msgstr \"\"\n";
  $output .= "\"Project-Id-Version: PROJECT VERSION\\n\"\n";
  $output .= '"POT-Creation-Date: ' . date("Y-m-d H:iO") . "\\n\"\n";
  $output .= '"PO-Revision-Date: ' . (isset($language) ? date("Y-m-d H:iO") : 'YYYY-mm-DD HH:MM+ZZZZ') . "\\n\"\n";
  $output .= "\"Last-Translator: NAME <EMAIL@ADDRESS>\\n\"\n";
  $output .= "\"Language-Team: " . (isset($language) ? $language->name : 'LANGUAGE') . " <EMAIL@ADDRESS>\\n\"\n";
  $output .= "\"MIME-Version: 1.0\\n\"\n";
  $output .= "\"Content-Type: text/plain; charset=utf-8\\n\"\n";
  $output .= "\"Content-Transfer-Encoding: 8bit\\n\"\n";
  if (isset($language->formula) && isset($language->plurals)) {
    $output .= "\"Plural-Forms: nplurals=" . $language->plurals . "; plural=" . strtr($language->formula, array(
      '$' => '',
    )) . ";\\n\"\n\n";
  }
  else {
    $output .= "\"Plural-Forms: nplurals=INTEGER; plural=EXPRESSION;\\n\"\n\n";
  }
  return $output;
}

/**
 * Write out generated files to the current folder.
 *
 * @param $http_filename
 *   File name for content-disposition header in case of usage
 *   over HTTP. If not given, files are written to the local filesystem.
 * @param $content_disposition
 *   See RFC2183. 'inline' or 'attachment', with a default of
 *   'inline'. Only used if $http_filename is set.
 * @todo
 *   Look into whether multiple files can be output via HTTP.
 */
function _potx_write_files($http_filename = NULL, $content_disposition = 'inline') {
  global $_potx_store;

  // Generate file lists and output files.
  if (is_array($_potx_store)) {
    foreach ($_potx_store as $file => $contents) {

      // Build replacement for file listing.
      if (count($contents['sources']) > 1) {
        $filelist = "Generated from files:\n#  " . join("\n#  ", $contents['sources']);
      }
      elseif (count($contents['sources']) == 1) {
        $filelist = "Generated from file: " . join('', $contents['sources']);
      }
      else {
        $filelist = 'No version information was available in the source files.';
      }
      $output = str_replace('--VERSIONS--', $filelist, $contents['header'] . $contents['strings']);
      if ($http_filename) {

        // HTTP output.
        header('Content-Type: text/plain; charset=utf-8');
        header('Content-Transfer-Encoding: 8bit');
        header("Content-Disposition: {$content_disposition}; filename={$http_filename}");
        print $output;
        return;
      }
      else {

        // Local file output, flatten directory structure.
        $file = str_replace('.', '-', preg_replace('![/]?([a-zA-Z_0-9]*/)*!', '', $file)) . '.pot';
        $fp = fopen($file, 'w');
        fwrite($fp, $output);
        fclose($fp);
      }
    }
  }
}

/**
 * Escape quotes in a strings depending on the surrounding
 * quote type used.
 *
 * @param $str
 *   The strings to escape
 */
function _potx_format_quoted_string($str) {
  $quo = substr($str, 0, 1);
  $str = substr($str, 1, -1);
  if ($quo == '"') {
    $str = stripcslashes($str);
  }
  else {
    $str = strtr($str, array(
      "\\'" => "'",
      "\\\\" => "\\",
    ));
  }
  return addcslashes($str, "\0..\37\\\"");
}

/**
 * Output a marker error with an extract of where the error was found.
 *
 * @param $file
 *   Name of file
 * @param $line
 *   Line number of error
 * @param $marker
 *   Function name with which the error was identified
 * @param $ti
 *   Index on the token array
 * @param $error
 *   Helpful error message for users.
 * @param $docs_url
 *   Documentation reference.
 */
function _potx_marker_error($file, $line, $marker, $ti, $error, $docs_url = NULL) {
  global $_potx_tokens;
  $tokens = '';
  $ti += 2;
  $tc = count($_potx_tokens);
  $par = 1;
  while ($tc - $ti > 0 && $par) {
    if (is_array($_potx_tokens[$ti])) {
      $tokens .= $_potx_tokens[$ti][1];
    }
    else {
      $tokens .= $_potx_tokens[$ti];
      if ($_potx_tokens[$ti] == "(") {
        $par++;
      }
      else {
        if ($_potx_tokens[$ti] == ")") {
          $par--;
        }
      }
    }
    $ti++;
  }
  potx_status('error', $error, $file, $line, $marker . '(' . $tokens, $docs_url);
}

/**
 * Status notification function.
 *
 * @param $op
 *   Operation to perform or type of message text.
 *     - set:    sets the reporting mode to $value
 *               use one of the POTX_STATUS_* constants as $value
 *     - get:    returns the list of error messages recorded
 *               if $value is true, it also clears the internal message cache
 *     - error:  sends an error message in $value with optional $file and $line
 *     - status: sends a status message in $value
 * @param $value
 *   Value depending on $op.
 * @param $file
 *   Name of file the error message is related to.
 * @param $line
 *   Number of line the error message is related to.
 * @param $excerpt
 *   Excerpt of the code in question, if available.
 * @param $docs_url
 *   URL to the guidelines to follow to fix the problem.
 */
function potx_status($op, $value = NULL, $file = NULL, $line = NULL, $excerpt = NULL, $docs_url = NULL) {
  static $mode = POTX_STATUS_CLI;
  static $messages = array();
  switch ($op) {
    case 'set':

      // Setting the reporting mode.
      $mode = $value;
      return;
    case 'get':

      // Getting the errors. Optionally deleting the messages.
      $errors = $messages;
      if (!empty($value)) {
        $messages = array();
      }
      return $errors;
    case 'error':
    case 'status':

      // Location information is required in 3 of the four possible reporting
      // modes as part of the error message. The structured mode needs the
      // file, line and excerpt info separately, not in the text.
      $location_info = '';
      if ($mode != POTX_STATUS_STRUCTURED && isset($file)) {
        if (isset($line)) {
          if (isset($excerpt)) {
            $location_info = t('At %excerpt in %file on line %line.', array(
              '%excerpt' => $excerpt,
              '%file' => $file,
              '%line' => $line,
            ));
          }
          else {
            $location_info = t('In %file on line %line.', array(
              '%file' => $file,
              '%line' => $line,
            ));
          }
        }
        else {
          if (isset($excerpt)) {
            $location_info = t('At %excerpt in %file.', array(
              '%excerpt' => $excerpt,
              '%file' => $file,
            ));
          }
          else {
            $location_info = t('In %file.', array(
              '%file' => $file,
            ));
          }
        }
      }

      // Documentation helpers are provided as readable text in most modes.
      $read_more = '';
      if ($mode != POTX_STATUS_STRUCTURED && isset($docs_url)) {
        $read_more = $mode == POTX_STATUS_CLI ? t('Read more at @url', array(
          '@url' => $docs_url,
        )) : t('Read more at <a href="@url">@url</a>', array(
          '@url' => $docs_url,
        ));
      }

      // Error message or progress text to display.
      switch ($mode) {
        case POTX_STATUS_MESSAGE:
          drupal_set_message(join(' ', array(
            $value,
            $location_info,
            $read_more,
          )), $op);
          break;
        case POTX_STATUS_CLI:
          fwrite($op == 'error' ? STDERR : STDOUT, join("\n", array(
            $value,
            $location_info,
            $read_more,
          )) . "\n\n");
          break;
        case POTX_STATUS_SILENT:
          if ($op == 'error') {
            $messages[] = join(' ', array(
              $value,
              $location_info,
              $read_more,
            ));
          }
          break;
        case POTX_STATUS_STRUCTURED:
          if ($op == 'error') {
            $messages[] = array(
              $value,
              $file,
              $line,
              $excerpt,
              $docs_url,
            );
          }
          break;
      }
      return;
  }
}

/**
 * Detect all occurances of t()-like calls.
 *
 * These sequences are searched for:
 *   T_STRING("$function_name") + "(" + T_CONSTANT_ENCAPSED_STRING + ")"
 *   T_STRING("$function_name") + "(" + T_CONSTANT_ENCAPSED_STRING + ","
 *
 * @param $file
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 * @param function_name
 *   The name of the function to look for (could be 't', '$t', 'st'
 *   or any other t-like function).
 * @param $string_mode
 *   String mode to use: POTX_STRING_INSTALLER, POTX_STRING_RUNTIME or
 *   POTX_STRING_BOTH.
 */
function _potx_find_t_calls($file, $save_callback, $function_name = 't', $string_mode = POTX_STRING_RUNTIME) {
  global $_potx_tokens, $_potx_lookup;

  // Lookup tokens by function name.
  if (isset($_potx_lookup[$function_name])) {
    foreach ($_potx_lookup[$function_name] as $ti) {
      list($prev, $ctok, $par, $mid, $rig) = array(
        $_potx_tokens[$ti - 1],
        $_potx_tokens[$ti],
        $_potx_tokens[$ti + 1],
        $_potx_tokens[$ti + 2],
        $_potx_tokens[$ti + 3],
      );
      list($type, $string, $line) = $ctok;
      if (is_array($prev) && $prev[0] == T_FUNCTION) {
        continue;
      }
      if ($function_name == 'debug' && is_array($prev) && $prev[0] != T_OBJECT_OPERATOR) {
        continue;
      }
      if ($par == "(") {
        if (in_array($rig, array(
          ")",
          ",",
        )) && (is_array($mid) && $mid[0] == T_CONSTANT_ENCAPSED_STRING)) {

          // This function is only used for context-less call types.
          $save_callback(_potx_format_quoted_string($mid[1]), POTX_CONTEXT_NONE, $file, $line, $string_mode);
        }
        else {

          // $function_name() found, but inside is something which is not a string literal.
          _potx_marker_error($file, $line, $function_name, $ti, t('The first parameter to @function() should be a literal string. There should be no variables, concatenation, constants or other non-literal strings there.', array(
            '@function' => $function_name,
          )), 'http://drupal.org/node/322732');
        }
      }
    }
  }
}

/**
 * Detect all occurances of t()-like calls from Drupal 7 (with context).
 *
 * These sequences are searched for:
 *   T_STRING("$function_name") + "(" + T_CONSTANT_ENCAPSED_STRING + ")"
 *   T_STRING("$function_name") + "(" + T_CONSTANT_ENCAPSED_STRING + ","
 *   and then an optional value for the replacements and an optional array
 *   for the options with an optional context key.
 *
 * @param $file
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 * @param function_name
 *   The name of the function to look for (could be 't', '$t', 'st'
 *   or any other t-like function). Drupal 7 only supports context on t(), st()
 *   and $t().
 * @param $string_mode
 *   String mode to use: POTX_STRING_INSTALLER, POTX_STRING_RUNTIME or
 *   POTX_STRING_BOTH.
 */
function _potx_find_t_calls_with_context($file, $save_callback, $function_name = 't', $string_mode = POTX_STRING_RUNTIME) {
  global $_potx_tokens, $_potx_lookup;

  // Lookup tokens by function name.
  if (isset($_potx_lookup[$function_name])) {
    foreach ($_potx_lookup[$function_name] as $ti) {
      if (count($_potx_tokens) <= $ti + 3 || $_potx_tokens[$ti + 1] != '(') {

        // This is not a t() call or similar, e.g. "TranslatableMarkup" in "class TranslationWrapper extends TranslatableMarkup {}"
        continue;
      }
      list($prev, $ctok, $par, $mid, $rig) = array(
        $_potx_tokens[$ti - 1],
        $_potx_tokens[$ti],
        $_potx_tokens[$ti + 1],
        $_potx_tokens[$ti + 2],
        $_potx_tokens[$ti + 3],
      );
      list($type, $string, $line) = $ctok;
      if (is_array($prev) && $prev[0] == T_FUNCTION) {
        continue;
      }
      if ($par == "(") {
        if (in_array($rig, array(
          ")",
          ",",
        )) && (is_array($mid) && $mid[0] == T_CONSTANT_ENCAPSED_STRING)) {

          // By default, there is no context.
          $context = POTX_CONTEXT_NONE;
          if ($rig == ',') {

            // If there was a comma after the string, we need to look forward
            // to try and find the context.
            $context = _potx_find_context($ti, $ti + 4, $file, $function_name);
          }
          if ($context !== POTX_CONTEXT_ERROR) {

            // Only save if there was no error in context parsing.
            $save_callback(_potx_format_quoted_string($mid[1]), $context, $file, $line, $string_mode);
          }
        }
        else {

          // $function_name() found, but inside is something which is not a string literal.
          _potx_marker_error($file, $line, $function_name, $ti, t('The first parameter to @function() should be a literal string. There should be no variables, concatenation, constants or other non-literal strings there.', array(
            '@function' => $function_name,
          )), 'http://drupal.org/node/322732');
        }
      }
    }
  }
}

/**
 * Detect all occurances of watchdog() calls. Only in Drupal 6 and Drupal 7.
 *
 * These sequences are searched for:
 *   watchdog + "(" + T_CONSTANT_ENCAPSED_STRING + "," +
 *   T_CONSTANT_ENCAPSED_STRING + something
 *
 * @param $file
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 */
function _potx_find_watchdog_calls($file, $save_callback) {
  global $_potx_tokens, $_potx_lookup;

  // Lookup tokens by function name.
  if (isset($_potx_lookup['watchdog'])) {
    foreach ($_potx_lookup['watchdog'] as $ti) {
      list($prev, $ctok, $par, $mtype, $comma, $message, $rig) = array(
        $_potx_tokens[$ti - 1],
        $_potx_tokens[$ti],
        $_potx_tokens[$ti + 1],
        $_potx_tokens[$ti + 2],
        $_potx_tokens[$ti + 3],
        $_potx_tokens[$ti + 4],
        $_potx_tokens[$ti + 5],
      );
      list($type, $string, $line) = $ctok;
      if (is_array($prev) && $prev[0] == T_FUNCTION) {
        continue;
      }
      if ($par == '(') {

        // Both type and message should be a string literal.
        if (in_array($rig, array(
          ')',
          ',',
        )) && $comma == ',' && (is_array($mtype) && $mtype[0] == T_CONSTANT_ENCAPSED_STRING) && (is_array($message) && $message[0] == T_CONSTANT_ENCAPSED_STRING)) {

          // Context is not supported on watchdog().
          $save_callback(_potx_format_quoted_string($mtype[1]), POTX_CONTEXT_NONE, $file, $line);
          $save_callback(_potx_format_quoted_string($message[1]), POTX_CONTEXT_NONE, $file, $line);
        }
        else {

          // watchdog() found, but inside is something which is not a string literal.
          _potx_marker_error($file, $line, 'watchdog', $ti, t('The first two watchdog() parameters should be literal strings. There should be no variables, concatenation, constants or even a t() call there.'), 'http://drupal.org/node/323101');
        }
      }
    }
  }
}

/**
 * Detect all occurances of log() calls.
 *
 * These sequences are searched for:
 *   log + "(" + ..anything (might be more tokens).. +
 *   "," + T_CONSTANT_ENCAPSED_STRING + whatever.
 *
 * @param $file
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 */
function _potx_find_log_calls($file, $save_callback) {
  global $_potx_tokens, $_potx_lookup;
  if (isset($_potx_lookup['log'])) {
    foreach ($_potx_lookup['log'] as $ti) {
      list($prev, $ctok, $par1) = array(
        $_potx_tokens[$ti - 1],
        $_potx_tokens[$ti],
        $_potx_tokens[$ti + 1],
      );
      list($type, $string, $line) = $ctok;
      if (is_array($prev) && $prev[0] == T_FUNCTION) {
        continue;
      }
      if ($par1 == "(") {

        // Eat up everything that is used as the first parameter
        $tn = $ti + 2;
        $depth = 0;
        while (!($_potx_tokens[$tn] == "," && $depth == 0)) {
          if ($_potx_tokens[$tn] == "(") {
            $depth++;
          }
          elseif ($_potx_tokens[$tn] == ")") {
            $depth--;
          }
          $tn++;
          if ($depth < 0) {

            // There is no second argument. This log() call was a false
            // positive, continue with the next one.
            continue 2;
          }
        }

        // Get further parameters
        list($comma, $message, $par2) = array(
          $_potx_tokens[$tn],
          $_potx_tokens[$tn + 1],
          $_potx_tokens[$tn + 2],
        );
        if ($comma == ',' && in_array($par2, array(
          ')',
          ',',
        )) && (is_array($message) && $message[0] == T_CONSTANT_ENCAPSED_STRING)) {

          // Context is not supported on watchdog().
          $save_callback(_potx_format_quoted_string($message[1]), POTX_CONTEXT_NONE, $file, $line);
        }
        else {

          // log() found, but the parameters are not correct.
          _potx_marker_error($file, $line, 'log', $ti, t('In log(), the log level should be followed by a literal string. There should be no variables, concatenation, constants or even a t() call there.'), 'http://drupal.org/node/323101');
        }
      }
    }
  }
}

/**
 * Detect all occurances of format_plural calls.
 *
 * These sequences are searched for:
 *   T_STRING("$function_name") + "(" + ..anything (might be more tokens).. +
 *   "," + T_CONSTANT_ENCAPSED_STRING +
 *   "," + T_CONSTANT_ENCAPSED_STRING + parenthesis (or comma allowed from
 *   Drupal 6)
 *
 * @param $file
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 * @param $function_name
 *   The name of the function to look for (could be 'format_plural' or
 *   'formatPlural').
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_find_format_plural_calls($file, $save_callback, $function_name = 'format_plural', $api_version = POTX_API_CURRENT) {
  global $_potx_tokens, $_potx_lookup;
  if (isset($_potx_lookup[$function_name])) {
    foreach ($_potx_lookup[$function_name] as $ti) {
      list($prev, $ctok, $par1) = array(
        $_potx_tokens[$ti - 1],
        $_potx_tokens[$ti],
        $_potx_tokens[$ti + 1],
      );
      list($type, $string, $line) = $ctok;
      if (is_array($prev) && $prev[0] == T_FUNCTION) {
        continue;
      }
      if ($par1 == "(") {

        // Eat up everything that is used as the first parameter
        $tn = $ti + 2;
        $depth = 0;
        while (!($_potx_tokens[$tn] == "," && $depth == 0)) {
          if ($_potx_tokens[$tn] == "(") {
            $depth++;
          }
          elseif ($_potx_tokens[$tn] == ")") {
            $depth--;
          }
          $tn++;
          if ($depth < 0) {

            // There is no second argument. This $function_name() call was a
            // false positive, continue with the next one.
            continue 2;
          }
        }

        // Get further parameters
        list($comma1, $singular, $comma2, $plural, $par2) = array(
          $_potx_tokens[$tn],
          $_potx_tokens[$tn + 1],
          $_potx_tokens[$tn + 2],
          $_potx_tokens[$tn + 3],
          $_potx_tokens[$tn + 4],
        );
        if ($comma2 == ',' && ($par2 == ')' || $par2 == ',' && $api_version > POTX_API_5) && (is_array($singular) && $singular[0] == T_CONSTANT_ENCAPSED_STRING) && (is_array($plural) && $plural[0] == T_CONSTANT_ENCAPSED_STRING)) {

          // By default, there is no context.
          $context = POTX_CONTEXT_NONE;
          if ($par2 == ',' && $api_version > POTX_API_6) {

            // If there was a comma after the plural, we need to look forward
            // to try and find the context.
            $context = _potx_find_context($ti, $tn + 5, $file, $function_name);
          }
          if ($context !== POTX_CONTEXT_ERROR) {

            // Only save if there was no error in context parsing.
            $save_callback(_potx_format_quoted_string($singular[1]) . "\0" . _potx_format_quoted_string($plural[1]), $context, $file, $line);
          }
        }
        else {

          // $function_name() found, but the parameters are not correct.
          _potx_marker_error($file, $line, $function_name, $ti, t('In @function(), the singular and plural strings should be literal strings. There should be no variables, concatenation, constants or even a t() call there.', array(
            '@function' => $function_name,
          )), 'http://drupal.org/node/323072');
        }
      }
    }
  }
}

/**
 * Detect permission names from the hook_perm() implementations.
 * Note that this will get confused with a similar pattern in a comment,
 * and with dynamic permissions, which need to be accounted for.
 *
 * @param $file
 *   Full path name of file parsed.
 * @param $filebase
 *   Filenaname of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 */
function _potx_find_perm_hook($file, $filebase, $save_callback) {
  global $_potx_tokens, $_potx_lookup;
  if (isset($_potx_lookup[$filebase . '_perm'])) {

    // Special case for node module, because it uses dynamic permissions.
    // Include the static permissions by hand. That's about all we can do here.
    if ($filebase == 'node') {
      $line = $_potx_tokens[$_potx_lookup['node_perm'][0]][2];

      // List from node.module 1.763 (checked in on 2006/12/29 at 21:25:36 by drumm)
      $nodeperms = array(
        'administer content types',
        'administer nodes',
        'access content',
        'view revisions',
        'revert revisions',
      );
      foreach ($nodeperms as $item) {

        // hook_perm() is only ever found on a Drupal system which does not
        // support context.
        $save_callback($item, POTX_CONTEXT_NONE, $file, $line);
      }
    }
    else {
      $count = 0;
      foreach ($_potx_lookup[$filebase . '_perm'] as $ti) {
        $tn = $ti;
        while (is_array($_potx_tokens[$tn]) || $_potx_tokens[$tn] != '}') {
          if (is_array($_potx_tokens[$tn]) && $_potx_tokens[$tn][0] == T_CONSTANT_ENCAPSED_STRING) {

            // hook_perm() is only ever found on a Drupal system which does not
            // support context.
            $save_callback(_potx_format_quoted_string($_potx_tokens[$tn][1]), POTX_CONTEXT_NONE, $file, $_potx_tokens[$tn][2]);
            $count++;
          }
          $tn++;
        }
      }
      if (!$count) {
        potx_status('error', t('%hook should have an array of literal string permission names.', array(
          '%hook' => $filebase . '_perm()',
        )), $file, NULL, NULL, 'http://drupal.org/node/323101');
      }
    }
  }
}

/**
 * Helper function to look up the token closing the current function.
 *
 * @param $here
 *   The token at the function name
 */
function _potx_find_end_of_function($here) {
  global $_potx_tokens;

  // Seek to open brace.
  while (is_array($_potx_tokens[$here]) || $_potx_tokens[$here] != '{') {
    $here++;
  }
  $nesting = 1;
  while ($nesting > 0) {
    $here++;
    if (!is_array($_potx_tokens[$here])) {
      if ($_potx_tokens[$here] == '}') {
        $nesting--;
      }
      if ($_potx_tokens[$here] == '{') {
        $nesting++;
      }
    }
  }
  return $here;
}

/**
 * Helper to move past t() and format_plural() arguments in search of context.
 *
 * @param $here
 *   The token before the start of the arguments
 */
function _potx_skip_args($here) {
  global $_potx_tokens;
  $nesting = 0;

  // Go through to either the end of the function call, or to a comma after the
  // current position on the same nesting level, or an unexpected semicolon.
  while (!($_potx_tokens[$here] == ',' && $nesting == 0 || $_potx_tokens[$here] == ')' && $nesting == -1 || $_potx_tokens[$here] === ';')) {
    $here++;
    if (!is_array($_potx_tokens[$here])) {
      if ($_potx_tokens[$here] == ')') {
        $nesting--;
      }
      if ($_potx_tokens[$here] == '(') {
        $nesting++;
      }
    }
  }
  if ($_potx_tokens[$here] === ';') {
    potx_status('error', t('Unexpected ;'));
  }

  // If we run out of nesting, it means we reached the end of the function call,
  // so we skipped the arguments but did not find meat for looking at the
  // specified context.
  return $nesting == 0 ? $here : FALSE;
}

/**
 * Helper to find the value for 'context' on t() and format_plural().
 *
 * @param $tf
 *   Start position of the original function.
 * @param $ti
 *   Start position where we should search from.
 * @param $file
 *   Full path name of file parsed.
 * @param function_name
 *   The name of the function to look for. Either 'format_plural' or 't'
 *   given that Drupal 7 only supports context on these.
 */
function _potx_find_context($tf, $ti, $file, $function_name) {
  global $_potx_tokens;

  // Start from after the comma and skip the possible arguments for the function
  // so we can look for the context.
  if (($ti = _potx_skip_args($ti)) && $_potx_tokens[$ti] == ',') {

    // Now we actually might have some definition for a context. The $options
    // argument is coming up, which might have a key for context.
    list($com, $arr, $par) = array(
      $_potx_tokens[$ti],
      $_potx_tokens[$ti + 1],
      $_potx_tokens[$ti + 2],
    );
    if ($com == ',' && ($forward = _potx_is_beginning_of_array($arr, $par))) {
      $nesting = 0;
      $ti += $forward;

      // Go through to either the end of the array or to the key definition of
      // context on the same nesting level.
      while (!(is_array($_potx_tokens[$ti]) && in_array($_potx_tokens[$ti][1], array(
        '"context"',
        "'context'",
      )) && $_potx_tokens[$ti][0] == T_CONSTANT_ENCAPSED_STRING && $nesting == 0 || _potx_is_end_of_array($_potx_tokens[$ti]) && $nesting == -1)) {
        $ti++;
        if (!is_array($_potx_tokens[$ti])) {

          // Treat each () and [] pair as going into / out of nesting levels.
          // There may be function or method calls as well as nested short
          // arrays within the arguments list. The list may be similar to:
          // array('langcode' => $obj->someMethod([])[2], 'context' => 'Long month name')
          // or
          // ['langcode' => $obj->someMethod(array())[2], 'context' => 'Long month name']
          if ($_potx_tokens[$ti] == ')' || $_potx_tokens[$ti] == ']') {
            $nesting--;
          }
          if ($_potx_tokens[$ti] == '(' || $_potx_tokens[$ti] == '[') {
            $nesting++;
          }
        }
      }
      if ($nesting == 0) {

        // Found the 'context' key on the top level of the $options array.
        list($arw, $str) = array(
          $_potx_tokens[$ti + 1],
          $_potx_tokens[$ti + 2],
        );
        if (is_array($arw) && $arw[1] == '=>' && is_array($str) && $str[0] == T_CONSTANT_ENCAPSED_STRING) {
          return _potx_format_quoted_string($str[1]);
        }
        else {
          list($type, $string, $line) = $_potx_tokens[$ti];

          // @todo: fix error reference.
          _potx_marker_error($file, $line, $function_name, $tf, t('The context element in the options array argument to @function() should be a literal string. There should be no variables, concatenation, constants or other non-literal strings there.', array(
            '@function' => $function_name,
          )), 'http://drupal.org/node/322732');

          // Return with error.
          return POTX_CONTEXT_ERROR;
        }
      }
      else {

        // Did not found 'context' key in $options array.
        return POTX_CONTEXT_NONE;
      }
    }
  }

  // After skipping args, we did not find a comma to look for $options.
  return POTX_CONTEXT_NONE;
}

/**
 * Determines if processing an array.
 *
 * @param string|string[] $arr
 * @param string|NULL $par
 *
 * @return int|FALSE
 *   The number to forward the current position forward to start processing the
 *   array. FALSE if not processing an array.
 */
function _potx_is_beginning_of_array($arr, $par) {
  if ($arr === '[' && is_array($par)) {
    return 2;
  }
  if (is_array($arr) && $arr[1] == 'array' && $par == '(') {
    return 3;
  }
  return FALSE;
}

/**
 * Determines if at the end of an array.
 *
 * @param string $token
 *   The token being processed.
 *
 * @return bool
 *   TRUE is  at the end of an array, FALSE if not.
 */
function _potx_is_end_of_array($token) {
  return $token == ')' || $token == ']';
}

/**
 * List of menu item titles. Only from Drupal 6.
 *
 * @param $file
 *   Full path name of file parsed.
 * @param $filebase
 *   Filenaname of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 */
function _potx_find_menu_hooks($file, $filebase, $save_callback) {
  global $_potx_tokens, $_potx_lookup;
  $hooks = array(
    '_menu',
    '_menu_alter',
  );
  $keys = array(
    "'title'",
    '"title"',
    "'description'",
    '"description"',
  );
  foreach ($hooks as $hook) {
    if (isset($_potx_lookup[$filebase . $hook]) && is_array($_potx_lookup[$filebase . $hook])) {

      // We have this menu hook in this file.
      foreach ($_potx_lookup[$filebase . $hook] as $ti) {
        $end = _potx_find_end_of_function($ti);
        $tn = $ti;
        while ($tn < $end) {

          // Support for array syntax more commonly used in menu hooks:
          // $items = array('node/add' => array('title' => 'Add content'));
          if ($_potx_tokens[$tn][0] == T_CONSTANT_ENCAPSED_STRING && in_array($_potx_tokens[$tn][1], $keys) && $_potx_tokens[$tn + 1][0] == T_DOUBLE_ARROW) {
            if ($_potx_tokens[$tn + 2][0] == T_CONSTANT_ENCAPSED_STRING) {

              // We cannot export menu item context.
              $save_callback(_potx_format_quoted_string($_potx_tokens[$tn + 2][1]), POTX_CONTEXT_NONE, $file, $_potx_tokens[$tn + 2][2]);
              $tn += 2;

              // Jump forward by 2.
            }
            else {
              potx_status('error', t('Invalid menu %element definition found in %hook. Title and description keys of the menu array should be literal strings.', array(
                '%element' => $_potx_tokens[$tn][1],
                '%hook' => $filebase . $hook . '()',
              )), $file, $_potx_tokens[$tn][2], NULL, 'http://drupal.org/node/323101');
            }
          }

          // Support for array syntax more commonly used in menu alters:
          // $items['node/add']['title'] = 'Add content here';
          if (is_string($_potx_tokens[$tn]) && $_potx_tokens[$tn] == '[' && $_potx_tokens[$tn + 1][0] == T_CONSTANT_ENCAPSED_STRING && in_array($_potx_tokens[$tn + 1][1], $keys) && is_string($_potx_tokens[$tn + 2]) && $_potx_tokens[$tn + 2] == ']') {
            if (is_string($_potx_tokens[$tn + 3]) && $_potx_tokens[$tn + 3] == '=' && $_potx_tokens[$tn + 4][0] == T_CONSTANT_ENCAPSED_STRING) {

              // We cannot export menu item context.
              $save_callback(_potx_format_quoted_string($_potx_tokens[$tn + 4][1]), POTX_CONTEXT_NONE, $file, $_potx_tokens[$tn + 4][2]);
              $tn += 4;

              // Jump forward by 4.
            }
            else {
              potx_status('error', t('Invalid menu %element definition found in %hook. Title and description keys of the menu array should be literal strings.', array(
                '%element' => $_potx_tokens[$tn + 1][1],
                '%hook' => $filebase . $hook . '()',
              )), $file, $_potx_tokens[$tn + 1][2], NULL, 'http://drupal.org/node/323101');
            }
          }
          $tn++;
        }
      }
    }
  }
}

/**
 * Get languages names from Drupal's locale.inc.
 *
 * @param $file
 *   Full path name of file parsed
 * @param $save_callback
 *   Callback function used to save strings.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_find_language_names($file, $save_callback, $api_version = POTX_API_CURRENT) {
  global $_potx_tokens, $_potx_lookup;
  if ($api_version > POTX_API_7) {
    $key = 'getStandardLanguageList';
  }
  elseif ($api_version > POTX_API_5) {
    $key = '_locale_get_predefined_list';
  }
  else {
    $key = '_locale_get_iso639_list';
  }
  foreach ($_potx_lookup[$key] as $ti) {

    // Search for the definition of _locale_get_predefined_list(), not where it is called.
    if ($_potx_tokens[$ti - 1][0] == T_FUNCTION) {
      break;
    }
  }
  $end = _potx_find_end_of_function($ti);
  $ti += 7;

  // function name, (, ), {, return, array, (
  while ($ti < $end) {
    while ($_potx_tokens[$ti][0] != T_ARRAY) {
      if (!is_array($_potx_tokens[$ti]) && $_potx_tokens[$ti] == ';') {

        // We passed the end of the list, break out to function level
        // to prevent an infinite loop.
        break 2;
      }
      $ti++;
    }
    $ti += 2;

    // array, (
    // Language names are context-less.
    $save_callback(_potx_format_quoted_string($_potx_tokens[$ti][1]), POTX_CONTEXT_NONE, $file, $_potx_tokens[$ti][2]);
  }
}

/**
 * Get the exact CVS version number from the file, so we can
 * push that into the generated output.
 *
 * @param $code
 *   Complete source code of the file parsed.
 * @param $file
 *   Name of the file parsed.
 * @param $version_callback
 *   Callback used to save the version information.
 */
function _potx_find_version_number($code, $file, $version_callback) {

  // Prevent CVS from replacing this pattern with actual info.
  if (preg_match('!\\$I' . 'd: ([^\\$]+) Exp \\$!', $code, $version_info)) {
    $version_callback($version_info[1], $file);
  }
  else {

    // Unknown version information.
    $version_callback($file . ': n/a', $file);
  }
}

/**
 * Add date strings, which cannot be extracted otherwise.
 * This is called for locale.module.
 *
 * @param $file
 *   Name of the file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_add_date_strings($file, $save_callback, $api_version = POTX_API_CURRENT) {
  for ($i = 1; $i <= 12; $i++) {
    $stamp = mktime(0, 0, 0, $i, 1, 1971);
    if ($api_version > POTX_API_6) {

      // From Drupal 7, long month names are saved with this context.
      $save_callback(date("F", $stamp), 'Long month name', $file);
    }
    elseif ($api_version > POTX_API_5) {

      // Drupal 6 uses a little hack. No context.
      $save_callback('!long-month-name ' . date("F", $stamp), POTX_CONTEXT_NONE, $file);
    }
    else {

      // Older versions just accept the confusion, no context.
      $save_callback(date("F", $stamp), POTX_CONTEXT_NONE, $file);
    }

    // Short month names lack a context anyway.
    $save_callback(date("M", $stamp), POTX_CONTEXT_NONE, $file);
  }
  for ($i = 0; $i <= 7; $i++) {
    $stamp = $i * 86400;
    $save_callback(date("D", $stamp), POTX_CONTEXT_NONE, $file);
    $save_callback(date("l", $stamp), POTX_CONTEXT_NONE, $file);
  }
  $save_callback('am', POTX_CONTEXT_NONE, $file);
  $save_callback('pm', POTX_CONTEXT_NONE, $file);
  $save_callback('AM', POTX_CONTEXT_NONE, $file);
  $save_callback('PM', POTX_CONTEXT_NONE, $file);
}

/**
 * Add format_interval special strings, which cannot be
 * extracted otherwise. This is called for common.inc
 *
 * @param $file
 *   Name of the file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_add_format_interval_strings($file, $save_callback, $api_version = POTX_API_CURRENT) {
  $components = array(
    '1 year' => '@count years',
    '1 week' => '@count weeks',
    '1 day' => '@count days',
    '1 hour' => '@count hours',
    '1 min' => '@count min',
    '1 sec' => '@count sec',
  );
  if ($api_version > POTX_API_6) {

    // Month support added in Drupal 7.
    $components['1 month'] = '@count months';
  }
  foreach ($components as $singular => $plural) {

    // Intervals support no context.
    $save_callback($singular . "\0" . $plural, POTX_CONTEXT_NONE, $file);
  }
}

/**
 * Add default theme region names, which cannot be extracted otherwise.
 * These default names are defined in system.module
 *
 * @param $file
 *   Name of the file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_add_default_region_names($file, $save_callback, $api_version = POTX_API_CURRENT) {
  $regions = array(
    'left' => 'Left sidebar',
    'right' => 'Right sidebar',
    'content' => 'Content',
    'header' => 'Header',
    'footer' => 'Footer',
  );
  if ($api_version > POTX_API_6) {
    $regions['highlight'] = 'Highlighted';
    $regions['help'] = 'Help';
    $regions['page_top'] = 'Page top';
    $regions['page_top'] = 'Page bottom';
  }
  foreach ($regions as $region) {

    // Regions come with the default context.
    $save_callback($region, POTX_CONTEXT_NONE, $file);
  }
}

/**
 * Parse an .info file and add relevant strings to the list.
 *
 * @param $file_path
 *   Complete file path to load contents with.
 * @param $file_name
 *   Stripped file name to use in outpout.
 * @param $strings
 *   Current strings array
 * @param $api_version
 *   Drupal API version to work with.
 */
function _potx_find_info_file_strings($file_path, $file_name, $save_callback, $api_version = POTX_API_CURRENT) {
  $info = array();
  if (file_exists($file_path)) {
    $info = $api_version > POTX_API_5 ? drupal_parse_info_file($file_path) : parse_ini_file($file_path);
  }

  // We need the name, description and package values. Others,
  // like core and PHP compatibility, timestamps or versions
  // are not to be translated.
  foreach (array(
    'name',
    'description',
    'package',
  ) as $key) {
    if (isset($info[$key])) {

      // No context support for .info file strings.
      $save_callback(addcslashes($info[$key], "\0..\37\\\""), POTX_CONTEXT_NONE, $file_name);
    }
  }

  // Add regions names from themes.
  if (isset($info['regions']) && is_array($info['regions'])) {
    foreach ($info['regions'] as $region => $region_name) {

      // No context support for .info file strings.
      $save_callback(addcslashes($region_name, "\0..\37\\\""), POTX_CONTEXT_NONE, $file_name);
    }
  }
}

/**
 * Parse a JavaScript file for translatables. Only from Drupal 6.
 *
 * Extracts strings wrapped in Drupal.t() and Drupal.formatPlural()
 * calls and inserts them into potx storage.
 *
 * Regex code lifted from _locale_parse_js_file().
 */
function _potx_parse_js_file($code, $file, $save_callback) {

  // Match all calls to Drupal.t() in an array.
  // Note: \s also matches newlines with the 's' modifier.
  preg_match_all('~
    [^\\w]Drupal\\s*\\.\\s*t\\s*                     # match "Drupal.t" with whitespace
    \\(\\s*                                       # match "(" argument list start
    (' . POTX_JS_STRING . ')\\s*                 # capture string argument
    (?:,\\s*' . POTX_JS_OBJECT . '\\s*            # optionally capture str args
      (?:,\\s*' . POTX_JS_OBJECT_CONTEXT . '\\s*) # optionally capture context
    ?)?                                         # close optional args
    \\)                                          # match ")" to finish
    ~sx', $code, $t_matches, PREG_SET_ORDER);

  // Add strings from Drupal.t().
  if (isset($t_matches) && count($t_matches)) {
    foreach ($t_matches as $match) {

      // Remove match from code to help us identify faulty Drupal.t() calls.
      $code = str_replace($match[0], '', $code);

      // Get context
      if (!empty($match[2])) {

        // Remove wrapping quotes
        $context = preg_replace('~^[\'"]|[\'"]$~', '', $match[2]);
        $context = _potx_parse_js_string($match[2]);
      }
      else {

        // Set context to null
        $context = POTX_CONTEXT_NONE;
      }
      $save_callback(_potx_parse_js_string($match[1]), $context, $file, 0);
    }
  }

  // Match all Drupal.formatPlural() calls in another array.
  preg_match_all('~
    [^\\w]Drupal\\s*\\.\\s*formatPlural\\s*  # match "Drupal.formatPlural" with whitespace
    \\(                                  # match "(" argument list start
    \\s*.+?\\s*,\\s*                       # match count argument
    (' . POTX_JS_STRING . ')\\s*,\\s*     # match singular string argument
    (                                   # capture plural string argument
      (?:                               # non-capturing group to repeat string pieces
        (?:
          \'                            # match start of single-quoted string
          (?:\\\\\'|[^\'])*             # match any character except unescaped single-quote
          @count                        # match "@count"
          (?:\\\\\'|[^\'])*             # match any character except unescaped single-quote
          \'                            # match end of single-quoted string
          |
          "                             # match start of double-quoted string
          (?:\\\\"|[^"])*               # match any character except unescaped double-quote
          @count                        # match "@count"
          (?:\\\\"|[^"])*               # match any character except unescaped double-quote
          "                             # match end of double-quoted string
        )
        (?:\\s*\\+\\s*)?                   # match "+" with possible whitespace, for str concat
      )+                                # match multiple because we supports concatenating strs
    )\\s*                                # end capturing of plural string argument
    (?:,\\s*' . POTX_JS_OBJECT . '\\s*              # optionally capture string args
      (?:,\\s*' . POTX_JS_OBJECT_CONTEXT . '\\s*)?  # optionally capture context
    )?
    \\)                                            # match ")" to finish
    ~sx', $code, $plural_matches, PREG_SET_ORDER);
  if (isset($plural_matches) && count($plural_matches)) {
    foreach ($plural_matches as $index => $match) {

      // Remove match from code to help us identify faulty
      // Drupal.formatPlural() calls later.
      $code = str_replace($match[0], '', $code);

      // Get context
      if (!empty($match[3])) {

        // Remove wrapping quotes
        $context = preg_replace('~^[\'"]|[\'"]$~', '', $match[3]);
        $context = _potx_parse_js_string($match[3]);
      }
      else {

        // Set context to null
        $context = POTX_CONTEXT_NONE;
      }
      $save_callback(_potx_parse_js_string($match[1]) . "\0" . _potx_parse_js_string($match[2]), $context, $file, 0);
    }
  }

  // Any remaining Drupal.t() or Drupal.formatPlural() calls are evil. This
  // regex is not terribly accurate (ie. code wrapped inside will confuse
  // the match), but we only need some unique part to identify the faulty calls.
  preg_match_all('~[^\\w]Drupal\\s*\\.\\s*(t|formatPlural)\\s*\\([^)]+\\)~s', $code, $faulty_matches, PREG_SET_ORDER);
  if (isset($faulty_matches) && count($faulty_matches)) {
    foreach ($faulty_matches as $index => $match) {
      $message = $match[1] == 't' ? t('Drupal.t() calls should have a single literal string as their first parameter.') : t('The singular and plural string parameters on Drupal.formatPlural() calls should be literal strings, plural containing a @count placeholder.');
      potx_status('error', $message, $file, NULL, $match[0], 'http://drupal.org/node/323109');
    }
  }
}

/**
 * Clean up string found in JavaScript source code. Only from Drupal 6.
 */
function _potx_parse_js_string($string) {
  return _potx_format_quoted_string(implode('', preg_split('~(?<!\\\\)[\'"]\\s*\\+\\s*[\'"]~s', $string)));
}

/**
 * Parse a Twig template for translatables. Drupal 8+.
 */
function _potx_parse_twig_file($code, $file, $save_callback) {

  // Extract front-matter data, and save text in certain ones.
  $keys_to_save = array(
    'label',
  );

  // Implementation copied from core's \Drupal\help_topics\FrontMatter class.
  $fm_separator = '---';
  $fm_regexp = '/\\A(' . $fm_separator . '(.*?)?\\R' . $fm_separator . ')(\\R.*)?\\Z/s';

  // Check for front matter data.
  $len = strlen($fm_separator);
  $matches = array();
  if (substr($code, 0, $len + 1) === $fm_separator . "\n" || substr($code, 0, $len + 2) === $fm_separator . "\r\n") {
    preg_match($fm_regexp, $code, $matches);
    $matches = array_map('trim', $matches);
  }
  if (!empty($matches[1])) {

    // Set the extracted source code.
    $code = $matches[3];
    try {
      $metadata = Yaml::parse($matches[2]);
      foreach ($metadata as $key => $content) {
        if (in_array($key, $keys_to_save, TRUE)) {
          $save_callback(_potx_format_quoted_string('"' . trim($content) . '"'), POTX_CONTEXT_NONE, $file, 1);
          break;
        }
      }
    } catch (ParseException $e) {
      potx_status('error', t("YAML parsing error on file @path: @error", array(
        '@path' => $file,
        '@error' => $e
          ->getMessage(),
      )), $file);
    }
  }
  $twig_lexer = new Twig_Lexer(new Twig_Environment());
  try {
    $stream = $twig_lexer
      ->tokenize($code, $file);
  } catch (Twig_Error_Syntax $e) {
    potx_status('error', t("Twig parsing error on file @path: @error", array(
      '@path' => $file,
      '@error' => $e
        ->getMessage(),
    )), $file);
    return;
  }
  while (!$stream
    ->isEOF()) {
    $token = $stream
      ->next();

    // Capture strings translated with the t or trans filter.
    if ($token
      ->test(Twig_Token::VAR_START_TYPE)) {
      $token = $stream
        ->next();
      if ($token
        ->test(Twig_Token::NAME_TYPE)) {
        continue;
      }
      $string = $token
        ->getValue();
      $line = $token
        ->getLine();
      $has_t = false;
      $chained = false;
      $is_concat = false;
      if ($stream
        ->test(Twig_Token::PUNCTUATION_TYPE, '.')) {
        $is_concat = true;
      }
      while (!$stream
        ->isEOF() && ($token = $stream
        ->next()) && !$token
        ->test(Twig_Token::VAR_END_TYPE)) {
        if ($token
          ->test(Twig_Token::PUNCTUATION_TYPE, '|')) {
          if ($stream
            ->test(array(
            't',
            'trans',
          ))) {
            $has_t = true;
          }
          else {
            $chained = true;
          }
        }
      }
      if ($has_t) {
        if (!$chained && !$is_concat) {
          $save_callback(_potx_format_quoted_string('"' . trim($string) . '"'), POTX_CONTEXT_NONE, $file, $line);
        }
        else {
          $message = t('Uses of the t filter in Twig templates should start with a single literal string, and should not be chained.');

          // TODO: Fill in specific URL for Twig documentation once it exists.
          potx_status('error', $message, $file, NULL, NULL, 'https://drupal.org/developing/api/localization');
        }
      }
    }
    elseif ($token
      ->test(Twig_Token::BLOCK_START_TYPE)) {
      $token = $stream
        ->next();
      if ($token
        ->test('trans')) {
        _potx_process_twig_trans_tag($stream, $file, $save_callback);
      }
    }
  }
}

/**
 * Parses a single {% trans %} tag, and extracts the translatable string.
 *
 * a {% trans %} tag can have the following formats:
 *   1. {% trans 'string' %}
 *   2. {% trans %} string {% endtrans %}
 *   3. {% trans %} singular string {% plural %} plural string {% endtrans %}
 *
 * @param Twig_TokenStream $stream
 */
function _potx_process_twig_trans_tag($stream, $file, $save_callback) {
  $is_plural = FALSE;
  $context = POTX_CONTEXT_NONE;

  // If the current token in the stream is a string, this trans tag
  // has a simple string argument to be translated.
  $token = $stream
    ->next();
  if ($token
    ->test(Twig_Token::STRING_TYPE)) {
    $text = $token
      ->getValue();

    // Check for context.
    $token = $stream
      ->next();
    if ($token
      ->test(Twig_Token::NAME_TYPE, 'with')) {
      $context = _potx_find_twig_trans_context($stream);
    }
    $save_callback(_potx_format_quoted_string('"' . trim($text) . '"'), $context, $file, $token
      ->getLine());
    return;
  }

  // Otherwise, we are in a trans/endtrans structure.
  $text = array();
  $line = $token
    ->getLine();

  // Process the stream until we reach the endtrans tag.
  while (!$stream
    ->isEOF() && !$token
    ->test('endtrans')) {

    // If it's text, add it to the translation.
    if ($token
      ->test(Twig_Token::TEXT_TYPE)) {
      $text[] = $token
        ->getValue();
    }
    elseif ($token
      ->test(Twig_Token::NAME_TYPE, 'with')) {
      $context = _potx_find_twig_trans_context($stream);
    }
    elseif ($token
      ->test('plural')) {
      $singular = implode('', $text);
      $is_plural = true;
      $text = array();

      // Skip past the 'count' token.
      $stream
        ->next();
    }
    elseif ($token
      ->test(Twig_Token::VAR_START_TYPE)) {
      $name = array();
      while ($stream
        ->look(1)
        ->test(Twig_Token::PUNCTUATION_TYPE, '.')) {
        $token = $stream
          ->next();
        $name[] = $token
          ->getValue();
        $stream
          ->next();
      }
      $token = $stream
        ->next();
      $name[] = $token
        ->getValue();

      // Figure out if it's escaped or placeholder.
      $prefix = '@';
      $token = $stream
        ->next();

      // If the next thing we see is |, this may be a placeholder. The only
      // "filter" supported is placeholder, so if there is any other filter
      // then we keep assuming it is to be escaped. (Even if later a
      // placeholder filter was attempted).
      if ($token
        ->test(Twig_Token::PUNCTUATION_TYPE, '|')) {
        $token = $stream
          ->next();
        if ($token
          ->getValue() == 'placeholder') {
          $prefix = '%';
        }
      }
      $text[] = $prefix . implode('.', $name);
    }
    $token = $stream
      ->next();
  }
  if ($is_plural) {
    $plural = implode('', $text);
    $save_callback(_potx_format_quoted_string('"' . trim($singular) . '"') . "\0" . _potx_format_quoted_string('"' . trim($plural) . '"'), $context, $file, $line);
  }
  else {
    $save_callback(_potx_format_quoted_string('"' . trim(implode('', $text)) . '"'), $context, $file, $line);
  }
}

/**
 * Look for a 'context' parameter in {% trans %} tags, that appear after the
 *   'with' keyword.
 */
function _potx_find_twig_trans_context($stream) {
  $token = $stream
    ->next();
  if ($token
    ->test(Twig_Token::PUNCTUATION_TYPE, '{')) {
    while (!$stream
      ->isEOF() && ($token = $stream
      ->next()) && !$token
      ->test(Twig_Token::PUNCTUATION_TYPE, '}')) {
      if ($token
        ->test(Twig_Token::STRING_TYPE, 'context')) {

        // Skip the ':' character.
        $stream
          ->next();
        $token = $stream
          ->next();
        if ($token
          ->test(Twig_Token::STRING_TYPE)) {
          return $token
            ->getValue();
        }
      }
    }
  }
  return POTX_CONTEXT_NONE;
}

/**
 * Detect all occurances of @Translation annotations in doc comments.
 *
 * @param $file
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 */
function _potx_find_translation_annotations($file, $save_callback) {
  global $_potx_tokens, $_potx_lookup;
  if (isset($_potx_lookup['T_DOC_COMMENT'])) {
    foreach ($_potx_lookup['T_DOC_COMMENT'] as $ti) {
      list($type, $string, $line) = $_potx_tokens[$ti];

      // Match for a possible empty string too, so we can signal that kind of
      // error in our standard way (from the save callback), instead of signaling
      // a generic error from here around syntax.
      preg_match_all('!=\\s*@Translation\\(\\s*"([^"]*)"(\\s*,\\s*context\\s*=\\s*("[^"]+"))?\\s*\\)!', $string, $found);
      if (isset($found) && is_array($found) && count($found[1])) {
        foreach ($found[1] as $index => $match) {
          $context = empty($found[3][$index]) ? POTX_CONTEXT_NONE : trim($found[3][$index], '"');
          $save_callback($match, $context, $file, $line);

          // Remove this annotation from the comment. This way if we have any
          // left after this foreach, we have bugos ones left and can use that
          // to signal an error.
          $string = str_replace($found[0][$index], '', $string);
        }
      }
      if (preg_match('!=\\s*@Translation!', $string) === 1) {

        // @Translation annotations still exist, so we have ones that did not
        // match the expected pattern.
        _potx_marker_error($file, $line, "@Translation", $ti, t('In @Translation, only one, non-empty static string is allowed in double quotes.'), 'https://drupal.org/node/1882526');
      }
    }
  }
}

/**
 * Initialize the list of translation patterns for YAML files.
 *
 * The patterns are loaded from a file named "yaml_translation_patterns.yml" in
 * potx's root. Contrib projects can also include their own
 * "yaml_translation_patterns.yml" file in their root folder to specify
 * translatable strings in their own custom yaml files.
 *
 * @param string $path
 *   The path to look for a custom "yaml_translation_patterns.yml" file.
 */
function _potx_init_yaml_translation_patterns($path = '') {
  global $yaml_translation_patterns;
  if (!is_array($yaml_translation_patterns)) {
    $yaml_translation_patterns = array();
    $default_patterns = __DIR__ . '/yaml_translation_patterns.yml';
    _potx_load_yaml_translation_patterns($default_patterns);
  }
  $custom_patterns = $path . '/yaml_translation_patterns.yml';
  if (!empty($path) && file_exists($custom_patterns)) {
    _potx_load_yaml_translation_patterns($custom_patterns);
  }
}

/**
 * Load the list of YAML translation patterns from a file.
 *
 * The file is expected to be in the following format:
 * @code
 *   # A list of file matching patterns (as expected by fnmatch()).
 *   - matches: *.test_format.yml:
 *     # A sequence of translatable keys in the matched YAML files.
 *     translatable_keys:
 *
 *       # Using the shorthand form
 *       - test_label
 *
 *       # Using the long form
 *       - key: test_label_2
 *         # An optional key, used as context for the translatable string.
 *         context: label_2_context
 *     # To mark all top-level keys as translatable,
 *     #   use the 'top_level_translatables' setting (optional; default: FALSE).
 *     top_level_translatables: TRUE
 * @endcode
 *
 * @param string $path
 *   The path for the YAML translation patterns file.
 */
function _potx_load_yaml_translation_patterns($path) {
  global $yaml_translation_patterns;
  $content = _potx_parse_yaml($path);
  if ($content === NULL) {
    return;
  }
  if (isset($content['translation_patterns'])) {
    $patterns = $content['translation_patterns'];
    foreach ($patterns as $pattern) {
      if (!isset($pattern['matches']) || !isset($pattern['translatable_keys'])) {
        continue;
      }
      $match = $pattern['matches'];
      $list = $pattern['translatable_keys'];
      foreach ($list as $item) {
        if (is_array($item)) {
          $yaml_translation_patterns[$match]['keys'][] = $item['key'];
          $yaml_translation_patterns[$match]['contexts'][$item['key']] = isset($item['context']) ? $item['context'] : NULL;
          $yaml_translation_patterns[$match]['array_translatables'][$item['key']] = isset($item['array_translatables']) ? $item['array_translatables'] : FALSE;
        }
        else {
          $yaml_translation_patterns[$match]['keys'][] = $item;
        }
      }
      $yaml_translation_patterns[$match]['top_level_translatables'] = isset($pattern['top_level_translatables']) ? $pattern['top_level_translatables'] : FALSE;
    }
  }
}

/**
 * Parse a YAML file for translatables. Drupal 8+.
 */
function _potx_parse_yaml_file($code, $file_name, $file_path, $save_callback) {
  global $yaml_translation_patterns;
  global $potx_callbacks;
  global $_potx_module_metadata;
  if (!is_array($yaml_translation_patterns)) {
    _potx_init_yaml_translation_patterns();
  }
  try {
    $yaml = Yaml::parse($code);

    // Don't try to process empty yaml files.
    if (!is_array($yaml)) {
      return;
    }
  } catch (ParseException $e) {
    potx_status('error', t("YAML parsing error on file @path: @error", array(
      '@path' => $file_path,
      '@error' => $e
        ->getMessage(),
    )), $file_path);
    return;
  }
  foreach ($yaml_translation_patterns as $pattern => $trans_list) {
    if (fnmatch($pattern, $file_name) || fnmatch('*/' . $pattern, $file_name)) {
      _potx_find_yaml_translatables($yaml, $trans_list, $file_name, $save_callback, TRUE);
    }
  }
  if (preg_match('~config/(schema|install|optional)/[^/]+\\.yml$~', $file_name, $matches)) {
    $module_name = basename(dirname(dirname(dirname($file_name))));
    $_potx_module_metadata[$module_name]['config'][$matches[1]][] = array(
      $file_name,
      $file_path,
    );
    if ($matches[1] == 'schema') {
      $keys = array_keys($yaml);
      $potx_callbacks['schema_store_lookup']($keys, $module_name);
    }
  }
  elseif (preg_match('~[^/]+\\.info\\.yml~', $file_name)) {
    $module_name = basename(dirname($file_name));
    $_potx_module_metadata[$module_name]['dependencies'] = [];

    // Module and theme projects have dependencies. Profiles have modules
    // listed in the install key.
    if (isset($yaml['dependencies'])) {
      $_potx_module_metadata[$module_name]['dependencies'] = $yaml['dependencies'];
    }
    if (isset($yaml['install'])) {
      $_potx_module_metadata[$module_name]['dependencies'] = $yaml['install'];
    }

    // Remove composer style naming prefix for dependencies.
    foreach ($_potx_module_metadata[$module_name]['dependencies'] as &$dependency) {
      $dependency = preg_replace('!^.+:(\\S+)!', '\\1', $dependency);
    }
  }
}

/**
 * Recursively look for translatable strings in a YAML file.
 *
 * @param array $yaml
 *   The parsed YAML data.
 * @param array $trans_list
 *   The list of translatable keys to look for, and (optionally) their contexts.
 * @param string $file_name
 *   Name of the file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 * @param bool $top_level
 *   Indicates that the top-level keys are being scanned.
 * @param bool $extract_array
 *   Set to TRUE to cause all array keys' values to be treated as translatable
 *   at this level of the YAML.
 */
function _potx_find_yaml_translatables(array $yaml, array $trans_list, $file_name, $save_callback, $top_level = FALSE, $extract_array = FALSE) {
  $extract_all = $top_level && $trans_list['top_level_translatables'] || $extract_array;
  foreach ($yaml as $key => $value) {
    if (is_array($value)) {

      // If the value is an array, we need to recurse, and possibly treat all
      // the next-level array keys as translatable.
      $extract_sub = isset($trans_list['array_translatables'][$key]) && $trans_list['array_translatables'][$key];
      _potx_find_yaml_translatables($value, $trans_list, $file_name, $save_callback, FALSE, $extract_sub);
    }
    elseif (in_array($key, $trans_list['keys'], TRUE) || $extract_all) {
      if (isset($trans_list['contexts'][$key])) {
        $context_key = $trans_list['contexts'][$key];
        if (isset($yaml[$context_key])) {
          $context = $yaml[$context_key];
        }
        else {
          $context = POTX_CONTEXT_NONE;
        }
      }
      else {
        $context = POTX_CONTEXT_NONE;
      }
      $save_callback(addcslashes($value, "\0..\37\\\""), $context, $file_name);
    }
  }
}

/**
 * Recursively process config schema into a flat structure.
 *
 * This structure is used to extract translatable strings from shipped
 * configuration, and identifies every element by joining all of its parent keys
 * (including itself) separated by the '+' symbol. It stores the schema elements
 * in four sublists:
 *  'translatables': the list of elements that are translatable.
 *  'types': the list of elements that rely on other schema elements for their
 *    definition. generally, those with types other than "mapping".
 *  'mappings': the list of elements that have a defined "mapping" property.
 *  'contexts': the list of elements that have a defined context string, using
 *    the "translation context" property.
 *
 * Note that 'types' and 'mappings' lists are not exclusive, i.e. an element can
 * both have a 'type' definition and a separate 'mapping'.
 *
 * Here is an example config schema:
 * @code
 *   test_schema:
 *     type: mapping
 *     mapping:
 *       name:
 *         type: label
 *       content:
 *         type: text
 *         translation context: Test schema content
 *       test_filter:
 *         type: filter
 * @endcode
 *
 * And the resulting processed schema:
 * @code
 * Array
 * (
 *   [translatables] => Array
 *     (
 *       [0] => test_schema+name
 *       [1] => test_schema+content
 *     )
 *
 *   [types] => Array
 *     (
 *       [test_schema+test_filter] => filter
 *     )
 *
 *   [mappings] => Array
 *     (
 *       [0] => test_schema
 *     )
 *
 *   [contexts] => Array
 *     (
 *       [test_schema+content] => Test schema content
 *     )
 *
 * )
 * @endcode
 *
 * @param string $schema_prefix
 *   All parent keys (including the element's key) joined by '+' symbol, e.g.
 *   image.style.*+effects+sequence
 * @param array $schema_data
 *   The schema subtree belonging to the current element.
 */
function _potx_process_config_schema($schema_prefix, $schema_data) {
  global $_potx_processed_schema;
  global $_potx_module_schema;

  // Elements can opt out of translation with a 'translatable: false' key.
  if (isset($schema_data['translatable']) && $schema_data['translatable'] === FALSE) {
    return;
  }

  // Do not process elements without a type, since the locale module strictly
  // requires translatable elements to be of base type 'string', and also we
  // can't traverse an element without knowing its type.
  if (!isset($schema_data['type'])) {
    return;
  }
  $type = $schema_data['type'];
  if (isset($schema_data['mapping'])) {
    foreach ($schema_data['mapping'] as $key => $element_data) {
      $element_key = $schema_prefix . '+' . $key;
      _potx_process_config_schema($element_key, $element_data);
    }
    if ($type != 'mapping') {
      $_potx_processed_schema['types'][$schema_prefix] = $type;
      $_potx_module_schema['types'][$schema_prefix] = $type;
    }
    $_potx_processed_schema['mappings'][] = $schema_prefix;
    $_potx_module_schema['mappings'][] = $schema_prefix;
  }
  else {
    if ($type == 'sequence') {
      if (!isset($schema_data['sequence'])) {
        return;
      }
      $sequence_schema = isset($schema_data['sequence'][0]) ? $schema_data['sequence'][0] : $schema_data['sequence'];
      _potx_process_config_schema($schema_prefix . '+sequence', $sequence_schema);
      $_potx_processed_schema['types'][$schema_prefix] = 'sequence';
      $_potx_module_schema['types'][$schema_prefix] = 'sequence';
    }
    elseif (in_array($type, $_potx_processed_schema['translatables']) || isset($schema_data['translatable']) && $schema_data['translatable'] === TRUE) {
      $_potx_processed_schema['translatables'][] = $schema_prefix;
      $_potx_module_schema['translatables'][] = $schema_prefix;

      // Elements can define a context string, or inherit the context from their
      // defined type.
      if (isset($schema_data['translation context'])) {
        $_potx_processed_schema['contexts'][$schema_prefix] = $schema_data['translation context'];
        $_potx_module_schema['contexts'][$schema_prefix] = $schema_data['translation context'];
      }
      elseif (isset($_potx_processed_schema['contexts'][$type])) {
        $_potx_processed_schema['contexts'][$schema_prefix] = $_potx_processed_schema['contexts'][$type];
        $_potx_module_schema['contexts'][$schema_prefix] = $_potx_processed_schema['contexts'][$type];
      }
    }
    else {
      $_potx_processed_schema['types'][$schema_prefix] = $type;
      $_potx_module_schema['types'][$schema_prefix] = $type;
    }
  }
}

/**
 * Checks whether an element exists in the processed schema.
 *
 * @param string $type
 * @return boolean
 */
function _potx_element_has_schema($type) {
  global $_potx_processed_schema;
  if (empty($_potx_processed_schema)) {
    return FALSE;
  }

  // If an element doesn't exist in any of the extracted lists, it hasn't been
  // defined in schema. This is checked during processing shipped config.
  return in_array($type, $_potx_processed_schema['translatables']) || in_array($type, $_potx_processed_schema['mappings']) || isset($_potx_processed_schema['types'][$type]);
}

/**
 * Finds the possible schema keys that match with a config element name.
 *
 * @param string $name
 *   Name of the config element.
 */
function _potx_find_matching_schema_candidates($name) {
  $candidates = array(
    $name,
  );
  $replaced = preg_replace('/([^.:]+)([.:*]*)$/', '*\\2', $name);
  if ($replaced != $name) {
    $candidates[] = $replaced;
    $one_star = preg_replace('/\\.([:.*]*)$/', '.*', $replaced);
    if ($one_star != $replaced) {
      $candidates[] = $one_star;
    }
    $candidates = array_merge($candidates, _potx_find_matching_schema_candidates($replaced));
    $candidates = array_unique($candidates);
  }
  return $candidates;
}

/**
 * Find the schema element matching with a specific type.
 *
 * Based on Drupal\Core\Config\TypedConfigManager::getFallbackName($name)
 *
 * @param string $name
 *   Configuration name or key.
 *
 * @return null|string
 *   The resolved schema name for the given configuration name or key. Returns
 *   null if there is no schema name to fallback to. For example,
 *   breakpoint.breakpoint.module.toolbar.narrow will check for definitions in
 *   the following order:
 *     breakpoint.breakpoint.module.toolbar.*
 *     breakpoint.breakpoint.module.*.*
 *     breakpoint.breakpoint.module.*
 *     breakpoint.breakpoint.*.*.*
 *     breakpoint.breakpoint.*
 *     breakpoint.*.*.*.*
 *     breakpoint.*
 *   Colons are also used, for example,
 *   block.settings.system_menu_block:footer will check for definitions in the
 *   following order:
 *     block.settings.system_menu_block:*
 *     block.settings.*:*
 *     block.settings.*
 *     block.*.*:*
 *     block.*
 */
function _potx_find_matching_schema($name) {
  if (_potx_element_has_schema($name)) {
    return $name;
  }

  // Check for definition of $name with filesystem marker.
  $replaced = preg_replace('/([^.:]+)([.:*]*)$/', '*\\2', $name);
  if ($replaced != $name) {
    if (_potx_element_has_schema($replaced)) {
      return $replaced;
    }
    else {

      // No definition for this level. Collapse multiple wildcards to a single
      // wildcard to see if there is a greedy match. For example,
      // breakpoint.breakpoint.*.* becomes
      // breakpoint.breakpoint.*
      $one_star = preg_replace('/\\.([:.*]*)$/', '.*', $replaced);
      if ($one_star != $replaced && _potx_element_has_schema($one_star)) {
        return $one_star;
      }

      // Check for next level. For example, if breakpoint.breakpoint.* has
      // been checked and no match found then check breakpoint.*.*
      return _potx_find_matching_schema($replaced);
    }
  }
  return NULL;
}

/**
 * Replaces variables in configuration name.
 *
 * The configuration name may contain one or more variables to be replaced,
 * enclosed in square brackets like '[name]' and will follow the replacement
 * rules defined by the _potx_replace_variable() function.
 *
 * Based on Drupal\Core\Config\TypedConfigManager::replaceName($name, $data)
 *
 * @param string $name
 *   Configuration name with variables in square brackets.
 * @param mixed $data
 *   Configuration data for the element.
 * @return string
 *   Configuration name with variables replaced.
 */
function _potx_config_replace_name($name, $config_data) {
  if (preg_match_all("/\\[(.*)\\]/U", $name, $matches)) {

    // Build our list of '[value]' => replacement.
    $replace = array();
    foreach (array_combine($matches[0], $matches[1]) as $key => $value) {
      $replace[$key] = _potx_replace_variable($value, $config_data);
    }
    return strtr($name, $replace);
  }
  else {
    return $name;
  }
}

/**
 * Replaces variable values in included names with configuration data.
 *
 * Variable values are nested configuration keys that will be replaced by
 * their value or some of these special strings:
 * - '%key', will be replaced by the element's key.
 * - '%parent', to reference the parent element.
 *
 * There may be nested configuration keys separated by dots or more complex
 * patterns like '%parent.name' which references the 'name' value of the
 * parent element.
 *
 * Example patterns:
 * - 'name.subkey', indicates a nested value of the current element.
 * - '%parent.name', will be replaced by the 'name' value of the parent.
 * - '%parent.%key', will be replaced by the parent element's key.
 *
 * Based on
 *  Drupal\Core\Config\TypedConfigManager::replaceVariable($value, $data).
 *
 * @param string $value
 *   Variable value to be replaced.
 * @param mixed $data
 *   Configuration data for the element.
 *
 * @return string
 *   The replaced value if a replacement found or the original value if not.
 */
function _potx_replace_variable($value, $data) {
  $parts = explode('.', $value);

  // Process each value part, one at a time.
  while ($name = array_shift($parts)) {
    if (!is_array($data) || !isset($data[$name])) {

      // Key not found, return original value
      return $value;
    }
    elseif (!$parts) {
      $value = $data[$name];
      if (is_bool($value)) {
        $value = (int) $value;
      }

      // If no more parts left, this is the final property.
      return (string) $value;
    }
    else {
      $data = $data[$name];
    }
  }
}

/**
 * Parse shipped configuration for translatables. Drupal 8+
 *
 * @param string $save_callback
 * @param string $api_version
 */
function _potx_parse_shipped_configuration($save_callback = '_potx_save_string', $api_version = POTX_API_CURRENT) {
  global $_potx_module_metadata;
  global $_potx_processed_schema;
  global $_potx_processed_modules;
  global $potx_callbacks;
  foreach ($_potx_module_metadata as $module_name => $module_metadata) {

    // Reset the processed schema for every module.
    $_potx_processed_modules = array();
    $_potx_processed_schema = array(
      'translatables' => array(),
      'types' => array(),
      'mappings' => array(),
      'contexts' => array(),
    );

    // "core" contains the base data type and translatable definitions.
    _potx_process_module_schemas(array(
      'core',
    ));
    _potx_process_module_schemas(array(
      $module_name,
    ));
    if (isset($module_metadata['config']['install'])) {
      foreach ($module_metadata['config']['install'] as $config_paths) {
        $parsed_config = _potx_parse_yaml($config_paths[1]);
        if ($parsed_config === NULL) {
          continue;
        }

        // Dependencies defined in a config file itself should not be visible
        // to other config files. So, make a temp copy here, and revert after
        // parsing the config file.
        $temp = $_potx_processed_schema;
        if (isset($parsed_config['dependencies']['module'])) {
          _potx_process_module_schemas($parsed_config['dependencies']['module']);
        }

        // Find the schema that matches the config file.
        $path_info = pathinfo($config_paths[1]);
        $config_name = $path_info['filename'];
        $schema = _potx_find_matching_schema($config_name);
        if ($schema !== NULL) {
          _potx_find_shipped_config_translatables($parsed_config, $schema, NULL, NULL, $config_paths[0], $save_callback);
        }
        $_potx_processed_schema = $temp;
      }
    }
    if (isset($module_metadata['config']['optional'])) {

      // Optional configs are different, since they do not explicitly specify
      // which module they belong to.
      foreach ($module_metadata['config']['optional'] as $config_paths) {
        $_potx_processed_modules = array();
        $_potx_processed_schema = array(
          'translatables' => array(),
          'types' => array(),
          'mappings' => array(),
          'contexts' => array(),
        );
        _potx_process_module_schemas(array(
          'core',
        ));

        // Find the schema that matches the config file.
        $path_info = pathinfo($config_paths[1]);
        $config_name = $path_info['filename'];
        $parsed_config = _potx_parse_yaml($config_paths[1]);
        if ($parsed_config === NULL) {
          continue;
        }
        $match_candidates = _potx_find_matching_schema_candidates($config_name);
        $matched = $potx_callbacks['schema_reverse_lookup']($match_candidates);
        if ($matched === NULL) {
          continue;
        }
        _potx_process_module_schemas(array(
          $matched,
        ));
        if (isset($parsed_config['dependencies']['module'])) {
          _potx_process_module_schemas($parsed_config['dependencies']['module']);
        }
        $schema = _potx_find_matching_schema($config_name);
        _potx_find_shipped_config_translatables($parsed_config, $schema, NULL, NULL, $config_paths[0], $save_callback);
      }
    }
  }
}

/**
 * Helper function for parsing yaml files.
 *
 * @param string $yaml_path
 *   Path to the yaml file.
 *
 * @return array
 *   The parsed yaml, if it contains valid yaml. NULL if it's invalid or empty.
 */
function _potx_parse_yaml($yaml_path) {
  try {
    $code = file_get_contents($yaml_path);
    $yaml = Yaml::parse($code);
    return $yaml;
  } catch (ParseException $e) {
    potx_status('error', t("YAML parsing error on file @path: @error", array(
      '@path' => $yaml_path,
      '@error' => $e
        ->getMessage(),
    )), $yaml_path);
  }
  return NULL;
}

/**
 * Recursively process and merge the schemas required for parsing shipped config.
 *
 * Handles module dependencies, and config optional dependencies.
 *
 * @param array $module_list
 *   The list of modules that their schema should be processed.
 */
function _potx_process_module_schemas($module_list) {
  global $_potx_module_metadata;
  global $_potx_processed_modules;
  global $_potx_module_schema;
  global $potx_callbacks;

  // Remove modules that have already been processed.
  $module_list = array_diff($module_list, $_potx_processed_modules);
  if (count($module_list) == 0) {
    return;
  }

  // Mark as processed early, to prevent a loop while traversing dependency graph.
  $_potx_processed_modules = array_merge($_potx_processed_modules, $module_list);
  $dependencies = array();

  // Gather list of all dependencies for the current $module_list.
  foreach ($module_list as $module_name) {

    // If the module is directly available from the initial given path, their
    //  metadata is already available.
    if (isset($_potx_module_metadata[$module_name])) {
      if (!empty($_potx_module_metadata[$module_name]['dependencies'])) {
        $dependencies = array_merge($dependencies, $_potx_module_metadata[$module_name]['dependencies']);
      }
    }
    else {

      // Try to load the module metadata from the globally available modules
      //  (e.g. drupal install directory in local potx, database in l10n_server)
      if ($potx_callbacks['load_module_metadata']($module_name)) {
        $dependencies = array_merge($dependencies, $_potx_module_metadata[$module_name]['dependencies']);
      }
    }
  }
  if (!empty($dependencies)) {

    // Process schema for dependencies first.
    _potx_process_module_schemas($dependencies);
  }

  // If the schema for a module is already available, merge it.
  foreach ($module_list as $module_name) {
    $module_schema = $potx_callbacks['schema_load']($module_name);

    // If the module is not in the current parsed project, and its config schema can be found in the database
    if (!isset($_potx_module_metadata[$module_name]['config']['schema']) && $module_schema !== NULL) {

      // If its config schema isn't empty
      if (!empty($module_schema['types'])) {
        _potx_merge_processed_schema($module_schema);
      }

      // Remove from list of unprocessed modules.
      unset($module_list[array_search($module_name, $module_list)]);
    }
  }
  foreach ($module_list as $module_name) {
    if (!empty($_potx_module_metadata[$module_name]['config']['schema'])) {
      $_potx_module_schema = array(
        'translatables' => array(),
        'types' => array(),
        'mappings' => array(),
        'contexts' => array(),
      );
      foreach ($_potx_module_metadata[$module_name]['config']['schema'] as $file_paths) {
        $yaml = _potx_parse_yaml($file_paths[1]);
        if ($yaml === NULL) {
          continue;
        }
        foreach ($yaml as $key => $element) {
          _potx_process_config_schema($key, $element);
        }
      }
      $potx_callbacks['schema_store']($module_name);
    }
  }
}

/**
 * Merge a module's processed schema with the global schema storage.
 */
function _potx_merge_processed_schema($schema) {
  global $_potx_processed_schema;
  $_potx_processed_schema['translatables'] = array_merge($_potx_processed_schema['translatables'], $schema['translatables']);
  $_potx_processed_schema['types'] = array_merge($_potx_processed_schema['types'], $schema['types']);
  $_potx_processed_schema['mappings'] = array_merge($_potx_processed_schema['mappings'], $schema['mappings']);
  $_potx_processed_schema['contexts'] = array_merge($_potx_processed_schema['contexts'], $schema['contexts']);
}

/**
 * Recursively check elements in shipped configuration with the processed schema.
 *
 * To support complex cases of variable replacement, '%key' and '%parent'
 * indexes are defined for every element when available. 'key' and 'parent'
 * values are also passed through the function parameters, because $config might
 * be a scalar value, which would not accept an index. Parsing an element's
 * properties inherited from its 'type' are processed separately from the
 * properties defined through its 'mapping'.
 *
 * @param mixed $config
 *   The config element being processed.
 * @param string $schema_prefix
 *   All parent keys (including the element's key) joined by '+' symbol.
 * @param string $config_key
 *   The config element's key.
 * @param array $config_parent
 *   The config element's parent.
 * @param string $file_name
 *   Name of file parsed.
 * @param callable $save_callback
 *   Callback function used to save strings.
 */
function _potx_find_shipped_config_translatables($config, $schema_prefix, $config_key, $config_parent, $file_name, $save_callback) {
  global $_potx_processed_schema;
  if (in_array($schema_prefix, $_potx_processed_schema['translatables']) && is_string($config)) {
    if (isset($_potx_processed_schema['contexts'][$schema_prefix])) {
      $context = $_potx_processed_schema['contexts'][$schema_prefix];
    }
    else {
      $context = POTX_CONTEXT_NONE;
    }
    if (strpos($config, "\3") !== FALSE) {

      // Convert plural formatting from config to plural formatting in our
      // format (replacing \03 with \0).
      list($singular, $plural) = explode("\3", $config);
      $save_callback(addcslashes($singular, "\0..\37\\\"") . "\0" . addcslashes($plural, "\0..\37\\\""), $context, $file_name);
    }
    else {
      $save_callback(addcslashes($config, "\0..\37\\\""), $context, $file_name);
    }
  }
  else {

    // Resolve the config element's type in schema to a real type, replacing all
    // placeholders, and find the shipped config translatables based on that
    // type.
    if (isset($_potx_processed_schema['types'][$schema_prefix])) {
      $schema_type = $_potx_processed_schema['types'][$schema_prefix];
      if ($schema_type == 'sequence') {
        foreach ($config as $sequence_key => $sequence_item) {

          // '%key' and '%parent' keys are added to $config by potx. skip them.
          if ($sequence_key === '%parent' || $sequence_key === '%key') {
            continue;
          }
          if (is_array($sequence_item)) {
            $sequence_item['%key'] = $sequence_key;
            $sequence_type = _potx_config_replace_name($schema_prefix, $sequence_item);
          }
          else {
            $sequence_type = _potx_config_replace_name($schema_prefix, array(
              '%key' => $sequence_key,
            ));
          }
          _potx_find_shipped_config_translatables($sequence_item, $sequence_type . '+sequence', $sequence_key, NULL, $file_name, $save_callback);
        }
      }
      else {
        if (is_array($config)) {
          $schema_type = _potx_config_replace_name($schema_type, $config);
        }
        else {
          $schema_type = _potx_config_replace_name($schema_type, array(
            '%key' => $config_key,
            '%parent' => $config_parent,
          ));
        }
        $matching_schema = _potx_find_matching_schema($schema_type);
        _potx_find_shipped_config_translatables($config, $matching_schema, $config_key, $config_parent, $file_name, $save_callback);
      }
    }

    // Check the keys belonging to config element's schema's "mapping" key.
    if (in_array($schema_prefix, $_potx_processed_schema['mappings']) && is_array($config)) {
      foreach ($config as $key => $element) {

        // '%key' and '%parent' keys are added to $config by potx. skip them.
        if ($key === '%parent' || $key === '%key' || empty($element)) {
          continue;
        }
        if (!_potx_element_has_schema($schema_prefix . '+' . $key)) {
          continue;
        }
        if (is_array($element)) {
          $element['%parent'] = $config;
          $element['%key'] = $key;
        }
        _potx_find_shipped_config_translatables($element, $schema_prefix . '+' . $key, $key, $config, $file_name, $save_callback);
      }
    }
  }
}

/**
 * Detect validation constraint messages. Drupal 8+
 *
 * This sequences is searched for:
 *   T_POTX_CONSTRAINT = T_CONSTANT_ENCAPSED_STRING
 *
 * note: T_POTX_CONSTRAINT is marked for T_VARIABLE tokens inside .php files
 *   with the "Constraint" suffix, where the token is "$message", or ends
 *   with "Message"
 *
 * @param $file_name
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 */
function _potx_find_constraint_messages($file_name, $save_callback) {
  global $_potx_tokens, $_potx_lookup;
  if (!isset($_potx_lookup['T_POTX_CONSTRAINT'])) {
    return;
  }
  foreach ($_potx_lookup['T_POTX_CONSTRAINT'] as $key => $ti) {
    if ($_potx_tokens[$ti + 1] == '=' && $_potx_tokens[$ti + 2][0] == T_CONSTANT_ENCAPSED_STRING) {
      $str = $_potx_tokens[$ti + 2][1];

      // Find plural versions if available.
      if (strpos($str, '|') !== FALSE) {
        $quo = substr($str, 0, 1);
        $break = strpos($str, '|');
        $singular = substr($str, 0, $break) . $quo;
        $plural = $quo . substr($str, $break + 1);
        $save_callback(_potx_format_quoted_string($singular) . "\0" . _potx_format_quoted_string($plural), POTX_CONTEXT_NONE, $file_name, $_potx_tokens[$ti][2]);
      }
      else {
        $save_callback(_potx_format_quoted_string($str), POTX_CONTEXT_NONE, $file_name, $_potx_tokens[$ti][2]);
      }
    }
  }
}

/**
 * Process Twig inline templates inside PHP files. Drupal 8+
 *
 * The patterns searched for inline templates include:
 *   1. '#template' => T_CONSTANT_ENCAPSED_STRING
 *   2. ['#template'] = T_CONSTANT_ENCAPSED_STRING
 *
 * @param $file_name
 *   Name of file parsed.
 * @param $save_callback
 *   Callback function used to save strings.
 */
function _potx_process_inline_templates($file_name, $save_callback) {
  global $_potx_tokens, $_potx_lookup;
  if (!isset($_potx_lookup["'#template'"])) {
    return;
  }
  foreach ($_potx_lookup["'#template'"] as $key => $ti) {

    // check for pattern: '#template' => T_CONSTANT_ENCAPSED_STRING
    if ($_potx_tokens[$ti + 1][0] == T_DOUBLE_ARROW && $_potx_tokens[$ti + 2][0] == T_CONSTANT_ENCAPSED_STRING) {
      $str = $_potx_tokens[$ti + 2][1];
      _potx_parse_twig_file($str, $file_name, $save_callback);
    }
    elseif ($_potx_tokens[$ti - 1] == '[' && $_potx_tokens[$ti + 1] == ']' && $_potx_tokens[$ti + 2] == '=' && $_potx_tokens[$ti + 3][0] == T_CONSTANT_ENCAPSED_STRING) {
      $str = $_potx_tokens[$ti + 3][1];
      _potx_parse_twig_file($str, $file_name, $save_callback);
    }
  }
}

/**
 * Collect a list of file names relevant for extraction,
 * starting from the given path.
 *
 * @param $path
 *   Where to start searching for files recursively.
 *   Provide non-empty path values with a trailing slash.
 * @param $basename
 *   Allows the restriction of search to a specific basename
 *   (ie. to collect files for a specific module).
 * @param $api_version
 *   Drupal API version to work with.
 * @param $skip_self
 *   Skip potx related files. To be used when command line type of extraction
 *   is used and the potx files at in the webroot, and their strings should not
 *   end up in the generated template. Set to TRUE if skiping is needed.
 */
function _potx_explore_dir($path = '', $basename = '*', $api_version = POTX_API_CURRENT, $skip_self = FALSE) {

  // It would be so nice to just use GLOB_BRACE, but it is not available on all
  // operarting systems, so we are working around the missing functionality.
  $extensions = array(
    'php',
    'inc',
    'module',
    'engine',
    'theme',
    'install',
    'info',
    'profile',
  );
  if ($api_version > POTX_API_5) {
    $extensions[] = 'js';
  }
  if ($api_version > POTX_API_7) {
    $extensions[] = 'twig';
    $extensions[] = 'yml';
    _potx_init_yaml_translation_patterns($path);
  }
  $files = array();
  foreach ($extensions as $extension) {
    $files_here = glob($path . $basename . '.' . $extension);
    if (is_array($files_here)) {
      $files = array_merge($files, $files_here);
    }
    if ($basename != '*') {

      // Basename was specific, so look for things like basename.admin.inc as well.
      // If the basnename was *, the above glob() already covered this case.
      $files_here = glob($path . $basename . '.*.' . $extension);
      if (is_array($files_here)) {
        $files = array_merge($files, $files_here);
      }
    }
  }

  // Grab subdirectories.
  $dirs = glob($path . '*', GLOB_ONLYDIR);
  if (is_array($dirs)) {
    foreach ($dirs as $dir) {
      if (!preg_match("!(^|.+/)(CVS|\\.svn|\\.git|tests|Tests|vendor|node_modules)\$!", $dir)) {
        $files = array_merge($files, _potx_explore_dir("{$dir}/", $basename, $api_version, $skip_self));
      }
    }
  }

  // Skip API and test files. Also skip our own files, if that was requested.
  $skip_pattern = $skip_self ? '!(potx\\.inc|\\.api\\.php|\\.test)$!' : '!(\\.api\\.php|\\.test)$!';
  foreach ($files as $id => $file_name) {
    if (preg_match($skip_pattern, $file_name)) {
      unset($files[$id]);
    }
  }
  return $files;
}

/**
 * Default $version_callback used by the potx system. Saves values
 * to a global array to reduce memory consumption problems when
 * passing around big chunks of values.
 *
 * @param $value
 *   The ersion number value of $file. If NULL, the collected
 *   values are returned.
 * @param $file
 *   Name of file where the version information was found.
 */
function _potx_save_version($value = NULL, $file = NULL) {
  global $_potx_versions;
  if (isset($value)) {
    $_potx_versions[$file] = $value;
  }
  else {
    return $_potx_versions;
  }
}

/**
 * Default $save_callback used by the potx system. Saves values
 * to global arrays to reduce memory consumption problems when
 * passing around big chunks of values.
 *
 * @param $value
 *   The string value. If NULL, the array of collected values
 *   are returned for the given $string_mode.
 * @param $context
 *   From Drupal 7, separate contexts are supported. POTX_CONTEXT_NONE is
 *   the default, if the code does not specify a context otherwise.
 * @param $file
 *   Name of file where the string was found.
 * @param $line
 *   Line number where the string was found.
 * @param $string_mode
 *   String mode: POTX_STRING_INSTALLER, POTX_STRING_RUNTIME
 *   or POTX_STRING_BOTH.
 */
function _potx_save_string($value = NULL, $context = NULL, $file = NULL, $line = 0, $string_mode = POTX_STRING_RUNTIME) {
  global $_potx_strings, $_potx_install;
  if (isset($value)) {

    // Value set but empty. Mark error on empty translatable string. Only trim
    // for empty string checking, since we should store leading/trailing
    // whitespace as it appears in the string otherwise.
    $check_empty = trim($value);
    if (empty($check_empty)) {
      potx_status('error', t('Empty string attempted to be localized. Please do not leave test code for localization in your source.'), $file, $line);
      return;
    }
    switch ($string_mode) {
      case POTX_STRING_BOTH:

        // Mark installer strings as duplicates of runtime strings if
        // the string was both recorded in the runtime and in the installer.
        $_potx_install[$value][$context][$file][] = $line . ' (dup)';

      // Break intentionally missing.
      case POTX_STRING_RUNTIME:

        // Mark runtime strings as duplicates of installer strings if
        // the string was both recorded in the runtime and in the installer.
        $_potx_strings[$value][$context][$file][] = $line . ($string_mode == POTX_STRING_BOTH ? ' (dup)' : '');
        break;
      case POTX_STRING_INSTALLER:
        $_potx_install[$value][$context][$file][] = $line;
        break;
    }
  }
  else {
    return $string_mode == POTX_STRING_RUNTIME ? $_potx_strings : $_potx_install;
  }
}
if (!function_exists('t')) {

  // If invoked outside of Drupal, t() will not exist, but
  // used to format the error message, so we provide a replacement.
  function t($string, $args = array()) {
    return strtr($string, $args);
  }
}
if (!function_exists('drupal_parse_info_file')) {

  // If invoked outside of Drupal, drupal_parse_info_file() will not be available,
  // but we need this function to properly parse Drupal 6/7 .info files.
  // Directly copied from common.inc,v 1.756.2.76 2010/02/01 16:01:41 goba Exp.
  function drupal_parse_info_file($filename) {
    $info = array();
    $constants = get_defined_constants();
    if (!file_exists($filename)) {
      return $info;
    }
    $data = file_get_contents($filename);
    if (preg_match_all('
      @^\\s*                           # Start at the beginning of a line, ignoring leading whitespace
      ((?:
        [^=;\\[\\]]|                    # Key names cannot contain equal signs, semi-colons or square brackets,
        \\[[^\\[\\]]*\\]                  # unless they are balanced and not nested
      )+?)
      \\s*=\\s*                         # Key/value pairs are separated by equal signs (ignoring white-space)
      (?:
        ("(?:[^"]|(?<=\\\\)")*")|     # Double-quoted string, which may contain slash-escaped quotes/slashes
        (\'(?:[^\']|(?<=\\\\)\')*\')| # Single-quoted string, which may contain slash-escaped quotes/slashes
        ([^\\r\\n]*?)                   # Non-quoted string
      )\\s*$                           # Stop at the next end of a line, ignoring trailing whitespace
      @msx', $data, $matches, PREG_SET_ORDER)) {
      foreach ($matches as $match) {

        // Fetch the key and value string
        $i = 0;
        foreach (array(
          'key',
          'value1',
          'value2',
          'value3',
        ) as $var) {
          ${$var} = isset($match[++$i]) ? $match[$i] : '';
        }
        $value = stripslashes(substr($value1, 1, -1)) . stripslashes(substr($value2, 1, -1)) . $value3;

        // Parse array syntax
        $keys = preg_split('/\\]?\\[/', rtrim($key, ']'));
        $last = array_pop($keys);
        $parent =& $info;

        // Create nested arrays
        foreach ($keys as $key) {
          if ($key == '') {
            $key = count($parent);
          }
          if (!isset($parent[$key]) || !is_array($parent[$key])) {
            $parent[$key] = array();
          }
          $parent =& $parent[$key];
        }

        // Handle PHP constants.
        if (isset($constants[$value])) {
          $value = $constants[$value];
        }

        // Insert actual value
        if ($last == '') {
          $last = count($parent);
        }
        $parent[$last] = $value;
      }
    }
    return $info;
  }
}

Functions

Namesort descending Description
potx_finish_processing Executes tasks that need to happen after all the files have been processed.
potx_status Status notification function.
_potx_add_date_strings Add date strings, which cannot be extracted otherwise. This is called for locale.module.
_potx_add_default_region_names Add default theme region names, which cannot be extracted otherwise. These default names are defined in system.module
_potx_add_format_interval_strings Add format_interval special strings, which cannot be extracted otherwise. This is called for common.inc
_potx_build_files Creates complete file strings with _potx_store()
_potx_config_replace_name Replaces variables in configuration name.
_potx_element_has_schema Checks whether an element exists in the processed schema.
_potx_explore_dir Collect a list of file names relevant for extraction, starting from the given path.
_potx_find_constraint_messages Detect validation constraint messages. Drupal 8+
_potx_find_context Helper to find the value for 'context' on t() and format_plural().
_potx_find_end_of_function Helper function to look up the token closing the current function.
_potx_find_format_plural_calls Detect all occurances of format_plural calls.
_potx_find_info_file_strings Parse an .info file and add relevant strings to the list.
_potx_find_language_names Get languages names from Drupal's locale.inc.
_potx_find_log_calls Detect all occurances of log() calls.
_potx_find_matching_schema Find the schema element matching with a specific type.
_potx_find_matching_schema_candidates Finds the possible schema keys that match with a config element name.
_potx_find_menu_hooks List of menu item titles. Only from Drupal 6.
_potx_find_perm_hook Detect permission names from the hook_perm() implementations. Note that this will get confused with a similar pattern in a comment, and with dynamic permissions, which need to be accounted for.
_potx_find_shipped_config_translatables Recursively check elements in shipped configuration with the processed schema.
_potx_find_translation_annotations Detect all occurances of @Translation annotations in doc comments.
_potx_find_twig_trans_context Look for a 'context' parameter in {% trans %} tags, that appear after the 'with' keyword.
_potx_find_t_calls Detect all occurances of t()-like calls.
_potx_find_t_calls_with_context Detect all occurances of t()-like calls from Drupal 7 (with context).
_potx_find_version_number Get the exact CVS version number from the file, so we can push that into the generated output.
_potx_find_watchdog_calls Detect all occurances of watchdog() calls. Only in Drupal 6 and Drupal 7.
_potx_find_yaml_translatables Recursively look for translatable strings in a YAML file.
_potx_format_quoted_string Escape quotes in a strings depending on the surrounding quote type used.
_potx_get_header Returns a header generated for a given file
_potx_init_yaml_translation_patterns Initialize the list of translation patterns for YAML files.
_potx_is_beginning_of_array Determines if processing an array.
_potx_is_end_of_array Determines if at the end of an array.
_potx_load_yaml_translation_patterns Load the list of YAML translation patterns from a file.
_potx_marker_error Output a marker error with an extract of where the error was found.
_potx_merge_processed_schema Merge a module's processed schema with the global schema storage.
_potx_parse_js_file Parse a JavaScript file for translatables. Only from Drupal 6.
_potx_parse_js_string Clean up string found in JavaScript source code. Only from Drupal 6.
_potx_parse_shipped_configuration Parse shipped configuration for translatables. Drupal 8+
_potx_parse_twig_file Parse a Twig template for translatables. Drupal 8+.
_potx_parse_yaml Helper function for parsing yaml files.
_potx_parse_yaml_file Parse a YAML file for translatables. Drupal 8+.
_potx_process_config_schema Recursively process config schema into a flat structure.
_potx_process_file Process a file and put extracted information to the given parameters.
_potx_process_inline_templates Process Twig inline templates inside PHP files. Drupal 8+
_potx_process_module_schemas Recursively process and merge the schemas required for parsing shipped config.
_potx_process_twig_trans_tag Parses a single {% trans %} tag, and extracts the translatable string.
_potx_replace_variable Replaces variable values in included names with configuration data.
_potx_save_string Default $save_callback used by the potx system. Saves values to global arrays to reduce memory consumption problems when passing around big chunks of values.
_potx_save_version Default $version_callback used by the potx system. Saves values to a global array to reduce memory consumption problems when passing around big chunks of values.
_potx_skip_args Helper to move past t() and format_plural() arguments in search of context.
_potx_translation_export Export translations with a specific language.
_potx_write_files Write out generated files to the current folder.

Constants

Namesort descending Description
POTX_API_5 Parse source files in Drupal 5.x format.
POTX_API_6 Parse source files in Drupal 6.x format.
POTX_API_7 Parse source files in Drupal 7.x format.
POTX_API_8 Parse source files in Drupal 8.x format.
POTX_API_CURRENT The current Drupal major API verion.
POTX_BUILD_CORE Core parsing mode:
POTX_BUILD_MULTIPLE Multiple files mode:
POTX_BUILD_SINGLE Single file mode:
POTX_CONTEXT_ERROR When there was a context identification error.
POTX_CONTEXT_NONE When no context is used. Makes it easy to look these up.
POTX_JS_OBJECT Regular expression pattern used to match simple JS object literal.
POTX_JS_OBJECT_CONTEXT Regular expression to match an object containing a key 'context'.
POTX_JS_STRING Regular expression pattern used to localize JavaScript strings.
POTX_STATUS_CLI Command line status reporting.
POTX_STATUS_MESSAGE Drupal message based status reports.
POTX_STATUS_SILENT Silence status reports.
POTX_STATUS_STRUCTURED Structured array status logging.
POTX_STRING_BOTH Save string to both installer and runtime collection.
POTX_STRING_INSTALLER Save string to installer collection only.
POTX_STRING_RUNTIME Save string to runtime collection only.