<?php

/**

 * @file

 * The theme system, which controls the output of Drupal.

 *

 * The theme system allows for nearly all output of the Drupal system to be

 * customized by user themes.

 */

/**

 * @defgroup content_flags Content markers

 * @{

 * Markers used by theme_mark() and node_mark() to designate content.

 * @see theme_mark(), node_mark()

 */

/**

 * Mark content as read.

 */

define('MARK_READ', 0);

/**

 * Mark content as being new.

 */

define('MARK_NEW', 1);

/**

 * Mark content as being updated.

 */

define('MARK_UPDATED', 2);

/**

 * @} End of "Content markers".

 */

/**

 * Determines if a theme is available to use.

 *

 * @param $theme

 *   Either the name of a theme or a full theme object.

 *

 * @return

 *   Boolean TRUE if the theme is enabled or is the site administration theme;

 *   FALSE otherwise.

 */

function drupal_theme_access($theme) {

  if (is_object($theme)) {

    return _drupal_theme_access($theme);

  }

  else {

    $themes = list_themes();

    return isset($themes[$theme]) && _drupal_theme_access($themes[$theme]);

  }

}

/**

 * Helper function for determining access to a theme.

 *

 * @see drupal_theme_access()

 */

function _drupal_theme_access($theme) {

  $admin_theme = variable_get('admin_theme');

  return !empty($theme->status) || ($admin_theme && $theme->name == $admin_theme);

}

/**

 * Initializes the theme system by loading the theme.

 */

function drupal_theme_initialize() {

  global $theme, $user, $theme_key;

  // If $theme is already set, assume the others are set, too, and do nothing

  if (isset($theme)) {

    return;

  }

  drupal_bootstrap(DRUPAL_BOOTSTRAP_DATABASE);

  $themes = list_themes();

  // Only select the user selected theme if it is available in the

  // list of themes that can be accessed.

  $theme = !empty($user->theme) && drupal_theme_access($user->theme) ? $user->theme : variable_get('theme_default', 'bartik');

  // Allow modules to override the theme. Validation has already been performed

  // inside menu_get_custom_theme(), so we do not need to check it again here.

  $custom_theme = menu_get_custom_theme();

  $theme = !empty($custom_theme) ? $custom_theme : $theme;

  // Store the identifier for retrieving theme settings with.

  $theme_key = $theme;

  // Find all our ancestor themes and put them in an array.

  $base_theme = array();

  $ancestor = $theme;

  while ($ancestor && isset($themes[$ancestor]->base_theme)) {

    $ancestor = $themes[$ancestor]->base_theme;

    $base_theme[] = $themes[$ancestor];

  }

  _drupal_theme_initialize($themes[$theme], array_reverse($base_theme));

  // Themes can have alter functions, so reset the drupal_alter() cache.

  drupal_static_reset('drupal_alter');

  // Provide the page with information about the theme that's used, so that a

  // later Ajax request can be rendered using the same theme.

  // @see ajax_base_page_theme()

  $setting['ajaxPageState'] = array(

    'theme' => $theme_key,

    'theme_token' => drupal_get_token($theme_key),

  );

  drupal_add_js($setting, 'setting');

}

/**

 * Initializes the theme system given already loaded information.

 *

 * This function is useful to initialize a theme when no database is present.

 *

 * @param $theme

 *   An object with the following information:

 *     filename

 *       The .info file for this theme. The 'path' to

 *       the theme will be in this file's directory. (Required)

 *     owner

 *       The path to the .theme file or the .engine file to load for

 *       the theme. (Required)

 *     stylesheet

 *       The primary stylesheet for the theme. (Optional)

 *     engine

 *       The name of theme engine to use. (Optional)

 * @param $base_theme

 *    An optional array of objects that represent the 'base theme' if the

 *    theme is meant to be derivative of another theme. It requires

 *    the same information as the $theme object. It should be in

 *    'oldest first' order, meaning the top level of the chain will

 *    be first.

 * @param $registry_callback

 *   The callback to invoke to set the theme registry.

 */

function _drupal_theme_initialize($theme, $base_theme = array(), $registry_callback = '_theme_load_registry') {

  global $theme_info, $base_theme_info, $theme_engine, $theme_path;

  $theme_info = $theme;

  $base_theme_info = $base_theme;

  $theme_path = dirname($theme->filename);

  // Prepare stylesheets from this theme as well as all ancestor themes.

  // We work it this way so that we can have child themes override parent

  // theme stylesheets easily.

  $final_stylesheets = array();

  // Grab stylesheets from base theme

  foreach ($base_theme as $base) {

    if (!empty($base->stylesheets)) {

      foreach ($base->stylesheets as $media => $stylesheets) {

        foreach ($stylesheets as $name => $stylesheet) {

          $final_stylesheets[$media][$name] = $stylesheet;

        }

      }

    }

  }

  // Add stylesheets used by this theme.

  if (!empty($theme->stylesheets)) {

    foreach ($theme->stylesheets as $media => $stylesheets) {

      foreach ($stylesheets as $name => $stylesheet) {

        $final_stylesheets[$media][$name] = $stylesheet;

      }

    }

  }

  // And now add the stylesheets properly

  foreach ($final_stylesheets as $media => $stylesheets) {

    foreach ($stylesheets as $stylesheet) {

      drupal_add_css($stylesheet, array('group' => CSS_THEME, 'every_page' => TRUE, 'media' => $media));

    }

  }

  // Do basically the same as the above for scripts

  $final_scripts = array();

  // Grab scripts from base theme

  foreach ($base_theme as $base) {

    if (!empty($base->scripts)) {

      foreach ($base->scripts as $name => $script) {

        $final_scripts[$name] = $script;

      }

    }

  }

  // Add scripts used by this theme.

  if (!empty($theme->scripts)) {

    foreach ($theme->scripts as $name => $script) {

      $final_scripts[$name] = $script;

    }

  }

  // Add scripts used by this theme.

  foreach ($final_scripts as $script) {

    drupal_add_js($script, array('group' => JS_THEME, 'every_page' => TRUE));

  }

  $theme_engine = NULL;

  // Initialize the theme.

  if (isset($theme->engine)) {

    // Include the engine.

    include_once DRUPAL_ROOT . '/' . $theme->owner;

    $theme_engine = $theme->engine;

    if (function_exists($theme_engine . '_init')) {

      foreach ($base_theme as $base) {

        call_user_func($theme_engine . '_init', $base);

      }

      call_user_func($theme_engine . '_init', $theme);

    }

  }

  else {

    // include non-engine theme files

    foreach ($base_theme as $base) {

      // Include the theme file or the engine.

      if (!empty($base->owner)) {

        include_once DRUPAL_ROOT . '/' . $base->owner;

      }

    }

    // and our theme gets one too.

    if (!empty($theme->owner)) {

      include_once DRUPAL_ROOT . '/' . $theme->owner;

    }

  }

  if (isset($registry_callback)) {

    _theme_registry_callback($registry_callback, array($theme, $base_theme, $theme_engine));

  }

}

/**

 * Gets the theme registry.

 *

 * @param $complete

 *   Optional boolean to indicate whether to return the complete theme registry

 *   array or an instance of the ThemeRegistry class. If TRUE, the complete

 *   theme registry array will be returned. This is useful if you want to

 *   foreach over the whole registry, use array_* functions or inspect it in a

 *   debugger. If FALSE, an instance of the ThemeRegistry class will be

 *   returned, this provides an ArrayObject which allows it to be accessed

 *   with array syntax and  isset(), and should be more lightweight

 *   than the full registry. Defaults to TRUE.

 *

 * @return

 *   The complete theme registry array, or an instance of the ThemeRegistry

 *   class.

 */

function theme_get_registry($complete = TRUE) {

  // Use the advanced drupal_static() pattern, since this is called very often.

  static $drupal_static_fast;

  if (!isset($drupal_static_fast)) {

    $drupal_static_fast['registry'] = &drupal_static('theme_get_registry');

  }

  $theme_registry = &$drupal_static_fast['registry'];

  // Initialize the theme, if this is called early in the bootstrap, or after

  // static variables have been reset.

  if (!is_array($theme_registry)) {

    drupal_theme_initialize();

    $theme_registry = array();

  }

  $key = (int) $complete;

  if (!isset($theme_registry[$key])) {

    list($callback, $arguments) = _theme_registry_callback();

    if (!$complete) {

      $arguments[] = FALSE;

    }

    $theme_registry[$key] = call_user_func_array($callback, $arguments);

  }

  return $theme_registry[$key];

}

/**

 * Sets the callback that will be used by theme_get_registry().

 *

 * @param $callback

 *   The name of the callback function.

 * @param $arguments

 *   The arguments to pass to the function.

 */

function _theme_registry_callback($callback = NULL, array $arguments = array()) {

  static $stored;

  if (isset($callback)) {

    $stored = array($callback, $arguments);

  }

  return $stored;

}

/**

 * Gets the theme_registry cache; if it doesn't exist, builds it.

 *

 * @param $theme

 *   The loaded $theme object as returned by list_themes().

 * @param $base_theme

 *   An array of loaded $theme objects representing the ancestor themes in

 *   oldest first order.

 * @param $theme_engine

 *   The name of the theme engine.

 * @param $complete

 *   Whether to load the complete theme registry or an instance of the

 *   ThemeRegistry class.

 *

 * @return

 *   The theme registry array, or an instance of the ThemeRegistry class.

 */

function _theme_load_registry($theme, $base_theme = NULL, $theme_engine = NULL, $complete = TRUE) {

  if ($complete) {

    // Check the theme registry cache; if it exists, use it.

    $cached = cache_get("theme_registry:$theme->name");

    if (isset($cached->data)) {

      $registry = $cached->data;

    }

    else {

      // If not, build one and cache it.

      $registry = _theme_build_registry($theme, $base_theme, $theme_engine);

      // Only persist this registry if all modules are loaded. This assures a

      // complete set of theme hooks.

      if (module_load_all(NULL)) {

        _theme_save_registry($theme, $registry);

      }

    }

    return $registry;

  }

  else {

    return new ThemeRegistry('theme_registry:runtime:' . $theme->name, 'cache');

  }

}

/**

 * Writes the theme_registry cache into the database.

 */

function _theme_save_registry($theme, $registry) {

  cache_set("theme_registry:$theme->name", $registry);

}

/**

 * Forces the system to rebuild the theme registry.

 *

 * This function should be called when modules are added to the system, or when

 * a dynamic system needs to add more theme hooks.

 */

function drupal_theme_rebuild() {

  drupal_static_reset('theme_get_registry');

  cache_clear_all('theme_registry', 'cache', TRUE);

}

/**

 * Builds the run-time theme registry.

 *

 * Extends DrupalCacheArray to allow the theme registry to be accessed as a

 * complete registry, while internally caching only the parts of the registry

 * that are actually in use on the site. On cache misses the complete

 * theme registry is loaded and used to update the run-time cache.

 */

class ThemeRegistry Extends DrupalCacheArray {

  /**

   * Whether the partial registry can be persisted to the cache.

   *

   * This is only allowed if all modules and the request method is GET. theme()

   * should be very rarely called on POST requests and this avoids polluting

   * the runtime cache.

   */

  protected $persistable;

  /**

   * The complete theme registry array.

   */

  protected $completeRegistry;

  function __construct($cid, $bin) {

    $this->cid = $cid;

    $this->bin = $bin;

    $this->persistable = module_load_all(NULL) && $_SERVER['REQUEST_METHOD'] == 'GET';

    $data = array();

    if ($this->persistable && $cached = cache_get($this->cid, $this->bin)) {

      $data = $cached->data;

    }

    else {

      // If there is no runtime cache stored, fetch the full theme registry,

      // but then initialize each value to NULL. This allows offsetExists()

      // to function correctly on non-registered theme hooks without triggering

      // a call to resolveCacheMiss().

      $data = $this->initializeRegistry();

      if ($this->persistable) {

        $this->set($data);

      }

    }

    $this->storage = $data;

  }

  /**

   * Initializes the full theme registry.

   *

   * @return

   *   An array with the keys of the full theme registry, but the values

   *   initialized to NULL.

   */

  function initializeRegistry() {

    $this->completeRegistry = theme_get_registry();

    return array_fill_keys(array_keys($this->completeRegistry), NULL);

  }

  public function offsetExists($offset) {

    // Since the theme registry allows for theme hooks to be requested that

    // are not registered, just check the existence of the key in the registry.

    // Use array_key_exists() here since a NULL value indicates that the theme

    // hook exists but has not yet been requested.

    return array_key_exists($offset, $this->storage);

  }

  public function offsetGet($offset) {

    // If the offset is set but empty, it is a registered theme hook that has

    // not yet been requested. Offsets that do not exist at all were not

    // registered in hook_theme().

    if (isset($this->storage[$offset])) {

      return $this->storage[$offset];

    }

    elseif (array_key_exists($offset, $this->storage)) {

      return $this->resolveCacheMiss($offset);

    }

  }

  public function resolveCacheMiss($offset) {

    if (!isset($this->completeRegistry)) {

      $this->completeRegistry = theme_get_registry();

    }

    $this->storage[$offset] = $this->completeRegistry[$offset];

    if ($this->persistable) {

      $this->persist($offset);

    }

    return $this->storage[$offset];

  }

  public function set($data, $lock = TRUE) {

    $lock_name = $this->cid . ':' . $this->bin;

    if (!$lock || lock_acquire($lock_name)) {

      if ($cached = cache_get($this->cid, $this->bin)) {

        // Use array merge instead of union so that filled in values in $data

        // overwrite empty values in the current cache.

        $data = array_merge($cached->data, $data);

      }

      else {

        $registry = $this->initializeRegistry();

        $data = array_merge($registry, $data);

      }

      cache_set($this->cid, $data, $this->bin);

      if ($lock) {

        lock_release($lock_name);

      }

    }

  }

}

/**

 * Process a single implementation of hook_theme().

 *

 * @param $cache

 *   The theme registry that will eventually be cached; It is an associative

 *   array keyed by theme hooks, whose values are associative arrays describing

 *   the hook:

 *   - 'type': The passed-in $type.

 *   - 'theme path': The passed-in $path.

 *   - 'function': The name of the function generating output for this theme

 *     hook. Either defined explicitly in hook_theme() or, if neither 'function'

 *     nor 'template' is defined, then the default theme function name is used.

 *     The default theme function name is the theme hook prefixed by either

 *     'theme_' for modules or '$name_' for everything else. If 'function' is

 *     defined, 'template' is not used.

 *   - 'template': The filename of the template generating output for this

 *     theme hook. The template is in the directory defined by the 'path' key of

 *     hook_theme() or defaults to $path.

 *   - 'variables': The variables for this theme hook as defined in

 *     hook_theme(). If there is more than one implementation and 'variables' is

 *     not specified in a later one, then the previous definition is kept.

 *   - 'render element': The renderable element for this theme hook as defined

 *     in hook_theme(). If there is more than one implementation and

 *     'render element' is not specified in a later one, then the previous

 *     definition is kept.

 *   - 'preprocess functions': See theme() for detailed documentation.

 *   - 'process functions': See theme() for detailed documentation.

 * @param $name

 *   The name of the module, theme engine, base theme engine, theme or base

 *   theme implementing hook_theme().

 * @param $type

 *   One of 'module', 'theme_engine', 'base_theme_engine', 'theme', or

 *   'base_theme'. Unlike regular hooks that can only be implemented by modules,

 *   each of these can implement hook_theme(). _theme_process_registry() is

 *   called in aforementioned order and new entries override older ones. For

 *   example, if a theme hook is both defined by a module and a theme, then the

 *   definition in the theme will be used.

 * @param $theme

 *   The loaded $theme object as returned from list_themes().

 * @param $path

 *   The directory where $name is. For example, modules/system or

 *   themes/bartik.

 *

 * @see theme()

 * @see _theme_build_registry()

 * @see hook_theme()

 * @see list_themes()

 */

function _theme_process_registry(&$cache, $name, $type, $theme, $path) {

  $result = array();

  // Processor functions work in two distinct phases with the process

  // functions always being executed after the preprocess functions.

  $variable_process_phases = array(

    'preprocess functions' => 'preprocess',

    'process functions'    => 'process',

  );

  $hook_defaults = array(

    'variables' => TRUE,

    'render element' => TRUE,

    'pattern' => TRUE,

    'base hook' => TRUE,