--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/includes/form.inc	Tue Dec 23 14:28:28 2008 +0100
@@ -0,0 +1,2508 @@
+<?php
+// $Id: form.inc,v 1.265.2.4 2008/02/11 14:45:57 goba Exp $
+
+/**
+ * @defgroup forms Form builder functions
+ * @{
+ * Functions that build an abstract representation of a HTML form.
+ *
+ * All modules should declare their form builder functions to be in this
+ * group and each builder function should reference its validate and submit
+ * functions using \@see. Conversely, validate and submit functions should
+ * reference the form builder function using \@see. For examples, of this see
+ * system_modules_uninstall() or user_pass(), the latter of which has the
+ * following in its doxygen documentation:
+ *
+ * \@ingroup forms
+ * \@see user_pass_validate().
+ * \@see user_pass_submit().
+ *
+ * @} End of "defgroup forms".
+ */
+
+/**
+ * @defgroup form_api Form generation
+ * @{
+ * Functions to enable the processing and display of HTML forms.
+ *
+ * Drupal uses these functions to achieve consistency in its form processing and
+ * presentation, while simplifying code and reducing the amount of HTML that
+ * must be explicitly generated by modules.
+ *
+ * The drupal_get_form() function handles retrieving, processing, and
+ * displaying a rendered HTML form for modules automatically. For example:
+ *
+ * @code
+ * // Display the user registration form.
+ * $output = drupal_get_form('user_register');
+ * @endcode
+ *
+ * Forms can also be built and submitted programmatically without any user input
+ * using the drupal_execute() function.
+ *
+ * For information on the format of the structured arrays used to define forms,
+ * and more detailed explanations of the Form API workflow, see the
+ * @link http://api.drupal.org/api/file/developer/topics/forms_api_reference.html reference @endlink
+ * and the @link http://api.drupal.org/api/file/developer/topics/forms_api.html quickstart guide. @endlink
+ */
+
+/**
+ * Retrieves a form from a constructor function, or from the cache if
+ * the form was built in a previous page-load. The form is then passesed
+ * on for processing, after and rendered for display if necessary.
+ *
+ * @param $form_id
+ *   The unique string identifying the desired form. If a function
+ *   with that name exists, it is called to build the form array.
+ *   Modules that need to generate the same form (or very similar forms)
+ *   using different $form_ids can implement hook_forms(), which maps
+ *   different $form_id values to the proper form constructor function. Examples
+ *   may be found in node_forms(), search_forms(), and user_forms().
+ * @param ...
+ *   Any additional arguments are passed on to the functions called by
+ *   drupal_get_form(), including the unique form constructor function.
+ *   For example, the node_edit form requires that a node object be passed
+ *   in here when it is called.
+ * @return
+ *   The rendered form.
+ */
+function drupal_get_form($form_id) {
+  $form_state = array('storage' => NULL, 'submitted' => FALSE);
+
+  $args = func_get_args();
+  $cacheable = FALSE;
+
+  if (isset($_SESSION['batch_form_state'])) {
+    // We've been redirected here after a batch processing : the form has
+    // already been processed, so we grab the post-process $form_state value
+    // and move on to form display. See _batch_finished() function.
+    $form_state = $_SESSION['batch_form_state'];
+    unset($_SESSION['batch_form_state']);
+  }
+  else {
+    // If the incoming $_POST contains a form_build_id, we'll check the
+    // cache for a copy of the form in question. If it's there, we don't
+    // have to rebuild the form to proceed. In addition, if there is stored
+    // form_state data from a previous step, we'll retrieve it so it can
+    // be passed on to the form processing code.
+    if (isset($_POST['form_id']) && $_POST['form_id'] == $form_id && !empty($_POST['form_build_id'])) {
+      $form = form_get_cache($_POST['form_build_id'], $form_state);
+    }
+
+    // If the previous bit of code didn't result in a populated $form
+    // object, we're hitting the form for the first time and we need
+    // to build it from scratch.
+    if (!isset($form)) {
+      $form_state['post'] = $_POST;
+      // Use a copy of the function's arguments for manipulation
+      $args_temp = $args;
+      $args_temp[0] = &$form_state;
+      array_unshift($args_temp, $form_id);
+
+      $form = call_user_func_array('drupal_retrieve_form', $args_temp);
+      $form_build_id = 'form-'. md5(mt_rand());
+      $form['#build_id'] = $form_build_id;
+      drupal_prepare_form($form_id, $form, $form_state);
+      // Store a copy of the unprocessed form for caching and indicate that it
+      // is cacheable if #cache will be set.
+      $original_form = $form;
+      $cacheable = TRUE;
+      unset($form_state['post']);
+    }
+    $form['#post'] = $_POST;
+
+    // Now that we know we have a form, we'll process it (validating,
+    // submitting, and handling the results returned by its submission
+    // handlers. Submit handlers accumulate data in the form_state by
+    // altering the $form_state variable, which is passed into them by
+    // reference.
+    drupal_process_form($form_id, $form, $form_state);
+    if ($cacheable && !empty($form['#cache'])) {
+      // Caching is done past drupal_process_form so #process callbacks can
+      // set #cache. By not sending the form state, we avoid storing
+      // $form_state['storage'].
+      form_set_cache($form_build_id, $original_form, NULL);
+    }
+  }
+
+  // Most simple, single-step forms will be finished by this point --
+  // drupal_process_form() usually redirects to another page (or to
+  // a 'fresh' copy of the form) once processing is complete. If one
+  // of the form's handlers has set $form_state['redirect'] to FALSE,
+  // the form will simply be re-rendered with the values still in its
+  // fields.
+  //
+  // If $form_state['storage'] or $form_state['rebuild'] have been
+  // set by any submit or validate handlers, however, we know that
+  // we're in a complex multi-part process of some sort and the form's
+  // workflow is NOT complete. We need to construct a fresh copy of
+  // the form, passing in the latest $form_state in addition to any
+  // other variables passed into drupal_get_form().
+
+  if (!empty($form_state['rebuild']) || !empty($form_state['storage'])) {
+    $form = drupal_rebuild_form($form_id, $form_state, $args);
+  }
+
+  // If we haven't redirected to a new location by now, we want to
+  // render whatever form array is currently in hand.
+  return drupal_render_form($form_id, $form);
+}
+
+/**
+ * Retrieves a form, caches it and processes it with an empty $_POST.
+ *
+ * This function clears $_POST and passes the empty $_POST to the form_builder.
+ * To preserve some parts from $_POST, pass them in $form_state.
+ *
+ * If your AHAH callback simulates the pressing of a button, then your AHAH
+ * callback will need to do the same as what drupal_get_form would do when the
+ * button is pressed: get the form from the cache, run drupal_process_form over
+ * it and then if it needs rebuild, run drupal_rebuild_form over it. Then send
+ * back a part of the returned form.
+ * $form_state['clicked_button']['#array_parents'] will help you to find which
+ * part.
+ *
+ * @param $form_id
+ *   The unique string identifying the desired form. If a function
+ *   with that name exists, it is called to build the form array.
+ *   Modules that need to generate the same form (or very similar forms)
+ *   using different $form_ids can implement hook_forms(), which maps
+ *   different $form_id values to the proper form constructor function. Examples
+ *   may be found in node_forms(), search_forms(), and user_forms().
+ * @param $form_state
+ *   A keyed array containing the current state of the form. Most
+ *   important is the $form_state['storage'] collection.
+ * @param $args
+ *   Any additional arguments are passed on to the functions called by
+ *   drupal_get_form(), plus the original form_state in the beginning. If you
+ *   are getting a form from the cache, use $form['#parameters'] to shift off
+ *   the $form_id from its beginning then the resulting array can be used as
+ *   $arg here.
+ * @param $form_build_id
+ *   If the AHAH callback calling this function only alters part of the form,
+ *   then pass in the existing form_build_id so we can re-cache with the same
+ *   csid.
+ * @return
+ *   The newly built form.
+ */
+function drupal_rebuild_form($form_id, &$form_state, $args, $form_build_id = NULL) {
+  // Remove the first argument. This is $form_id.when called from
+  // drupal_get_form and the original $form_state when called from some AHAH
+  // callback. Neither is needed. After that, put in the current state.
+  $args[0] = &$form_state;
+  // And the form_id.
+  array_unshift($args, $form_id);
+  $form = call_user_func_array('drupal_retrieve_form', $args);
+
+  if (!isset($form_build_id)) {
+    // We need a new build_id for the new version of the form.
+    $form_build_id = 'form-'. md5(mt_rand());
+  }
+  $form['#build_id'] = $form_build_id;
+  drupal_prepare_form($form_id, $form, $form_state);
+
+  // Now, we cache the form structure so it can be retrieved later for
+  // validation. If $form_state['storage'] is populated, we'll also cache
+  // it so that it can be used to resume complex multi-step processes.
+  form_set_cache($form_build_id, $form, $form_state);
+
+  // Clear out all post data, as we don't want the previous step's
+  // data to pollute this one and trigger validate/submit handling,
+  // then process the form for rendering.
+  $_POST = array();
+  $form['#post'] = array();
+  drupal_process_form($form_id, $form, $form_state);
+  return $form;
+}
+
+/**
+ * Fetch a form from cache.
+ */
+function form_get_cache($form_build_id, &$form_state) {
+  if ($cached = cache_get('form_'. $form_build_id, 'cache_form')) {
+    $form = $cached->data;
+    if ($cached = cache_get('storage_'. $form_build_id, 'cache_form')) {
+      $form_state['storage'] = $cached->data;
+    }
+    return $form;
+  }
+}
+
+/**
+ * Store a form in the cache
+ */
+function form_set_cache($form_build_id, $form, $form_state) {
+  $expire = max(ini_get('session.cookie_lifetime'), 86400);
+
+  cache_set('form_'. $form_build_id, $form, 'cache_form', $expire);
+  if (!empty($form_state['storage'])) {
+    cache_set('storage_'. $form_build_id, $form_state['storage'], 'cache_form', $expire);
+  }
+}
+
+/**
+ * Retrieves a form using a form_id, populates it with $form_state['values'],
+ * processes it, and returns any validation errors encountered. This
+ * function is the programmatic counterpart to drupal_get_form().
+ *
+ * @param $form_id
+ *   The unique string identifying the desired form. If a function
+ *   with that name exists, it is called to build the form array.
+ *   Modules that need to generate the same form (or very similar forms)
+ *   using different $form_ids can implement hook_forms(), which maps
+ *   different $form_id values to the proper form constructor function. Examples
+ *   may be found in node_forms(), search_forms(), and user_forms().
+ * @param $form_state
+ *   A keyed array containing the current state of the form. Most
+ *   important is the $form_state['values'] collection, a tree of data
+ *   used to simulate the incoming $_POST information from a user's
+ *   form submission.
+ * @param ...
+ *   Any additional arguments are passed on to the functions called by
+ *   drupal_execute(), including the unique form constructor function.
+ *   For example, the node_edit form requires that a node object be passed
+ *   in here when it is called.
+ * For example:
+ *
+ * // register a new user
+ * $form_state = array();
+ * $form_state['values']['name'] = 'robo-user';
+ * $form_state['values']['mail'] = 'robouser@example.com';
+ * $form_state['values']['pass'] = 'password';
+ * $form_state['values']['op'] = t('Create new account');
+ * drupal_execute('user_register', $form_state);
+ *
+ * // Create a new node
+ * $form_state = array();
+ * module_load_include('inc', 'node', 'node.pages');
+ * $node = array('type' => 'story');
+ * $form_state['values']['title'] = 'My node';
+ * $form_state['values']['body'] = 'This is the body text!';
+ * $form_state['values']['name'] = 'robo-user';
+ * $form_state['values']['op'] = t('Save');
+ * drupal_execute('story_node_form', $form_state, (object)$node);
+ */
+function drupal_execute($form_id, &$form_state) {
+  $args = func_get_args();
+  $form = call_user_func_array('drupal_retrieve_form', $args);
+  $form['#post'] = $form_state['values'];
+  drupal_prepare_form($form_id, $form, $form_state);
+  drupal_process_form($form_id, $form, $form_state);
+}
+
+/**
+ * Retrieves the structured array that defines a given form.
+ *
+ * @param $form_id
+ *   The unique string identifying the desired form. If a function
+ *   with that name exists, it is called to build the form array.
+ *   Modules that need to generate the same form (or very similar forms)
+ *   using different $form_ids can implement hook_forms(), which maps
+ *   different $form_id values to the proper form constructor function.
+ * @param $form_state
+ *   A keyed array containing the current state of the form.
+ * @param ...
+ *   Any additional arguments needed by the unique form constructor
+ *   function. Generally, these are any arguments passed into the
+ *   drupal_get_form() or drupal_execute() functions after the first
+ *   argument. If a module implements hook_forms(), it can examine
+ *   these additional arguments and conditionally return different
+ *   builder functions as well.
+ */
+function drupal_retrieve_form($form_id, &$form_state) {
+  static $forms;
+
+  // We save two copies of the incoming arguments: one for modules to use
+  // when mapping form ids to constructor functions, and another to pass to
+  // the constructor function itself. We shift out the first argument -- the
+  // $form_id itself -- from the list to pass into the constructor function,
+  // since it's already known.
+  $args = func_get_args();
+  $saved_args = $args;
+  array_shift($args);
+  if (isset($form_state)) {
+    array_shift($args);
+  }
+
+  // We first check to see if there's a function named after the $form_id.
+  // If there is, we simply pass the arguments on to it to get the form.
+  if (!function_exists($form_id)) {
+    // In cases where many form_ids need to share a central constructor function,
+    // such as the node editing form, modules can implement hook_forms(). It
+    // maps one or more form_ids to the correct constructor functions.
+    //
+    // We cache the results of that hook to save time, but that only works
+    // for modules that know all their form_ids in advance. (A module that
+    // adds a small 'rate this comment' form to each comment in a list
+    // would need a unique form_id for each one, for example.)
+    //
+    // So, we call the hook if $forms isn't yet populated, OR if it doesn't
+    // yet have an entry for the requested form_id.
+    if (!isset($forms) || !isset($forms[$form_id])) {
+      $forms = module_invoke_all('forms', $form_id, $args);
+    }
+    $form_definition = $forms[$form_id];
+    if (isset($form_definition['callback arguments'])) {
+      $args = array_merge($form_definition['callback arguments'], $args);
+    }
+    if (isset($form_definition['callback'])) {
+      $callback = $form_definition['callback'];
+    }
+  }
+
+  array_unshift($args, NULL);
+  $args[0] = &$form_state;
+
+  // If $callback was returned by a hook_forms() implementation, call it.
+  // Otherwise, call the function named after the form id.
+  $form = call_user_func_array(isset($callback) ? $callback : $form_id, $args);
+
+  // We store the original function arguments, rather than the final $arg
+  // value, so that form_alter functions can see what was originally
+  // passed to drupal_retrieve_form(). This allows the contents of #parameters
+  // to be saved and passed in at a later date to recreate the form.
+  $form['#parameters'] = $saved_args;
+  return $form;
+}
+
+/**
+ * This function is the heart of form API. The form gets built, validated and in
+ * appropriate cases, submitted.
+ *
+ * @param $form_id
+ *   The unique string identifying the current form.
+ * @param $form
+ *   An associative array containing the structure of the form.
+ * @param $form_state
+ *   A keyed array containing the current state of the form. This
+ *   includes the current persistent storage data for the form, and
+ *   any data passed along by earlier steps when displaying a
+ *   multi-step form. Additional information, like the sanitized $_POST
+ *   data, is also accumulated here.
+ */
+function drupal_process_form($form_id, &$form, &$form_state) {
+  $form_state['values'] = array();
+
+  $form = form_builder($form_id, $form, $form_state);
+  // Only process the form if it is programmed or the form_id coming
+  // from the POST data is set and matches the current form_id.
+  if ((!empty($form['#programmed'])) || (!empty($form['#post']) && (isset($form['#post']['form_id']) && ($form['#post']['form_id'] == $form_id)))) {
+    drupal_validate_form($form_id, $form, $form_state);
+
+    // form_clean_id() maintains a cache of element IDs it has seen,
+    // so it can prevent duplicates. We want to be sure we reset that
+    // cache when a form is processed, so scenerios that result in
+    // the form being built behind the scenes and again for the
+    // browser don't increment all the element IDs needlessly.
+    form_clean_id(NULL, TRUE);
+
+    if ((!empty($form_state['submitted'])) && !form_get_errors() && empty($form_state['rebuild'])) {
+      $form_state['redirect'] = NULL;
+      form_execute_handlers('submit', $form, $form_state);
+
+      // We'll clear out the cached copies of the form and its stored data
+      // here, as we've finished with them. The in-memory copies are still
+      // here, though.
+      if (variable_get('cache', CACHE_DISABLED) == CACHE_DISABLED && !empty($form_state['values']['form_build_id'])) {
+        cache_clear_all('form_'. $form_state['values']['form_build_id'], 'cache_form');
+        cache_clear_all('storage_'. $form_state['values']['form_build_id'], 'cache_form');
+      }
+
+      // If batches were set in the submit handlers, we process them now,
+      // possibly ending execution. We make sure we do not react to the batch
+      // that is already being processed (if a batch operation performs a
+      // drupal_execute).
+      if ($batch =& batch_get() && !isset($batch['current_set'])) {
+        // The batch uses its own copies of $form and $form_state for
+        // late execution of submit handers and post-batch redirection.
+        $batch['form'] = $form;
+        $batch['form_state'] = $form_state;
+        $batch['progressive'] = !$form['#programmed'];
+        batch_process();
+        // Execution continues only for programmatic forms.
+        // For 'regular' forms, we get redirected to the batch processing
+        // page. Form redirection will be handled in _batch_finished(),
+        // after the batch is processed.
+      }
+
+      // If no submit handlers have populated the $form_state['storage']
+      // bundle, and the $form_state['rebuild'] flag has not been set,
+      // we're finished and should redirect to a new destination page
+      // if one has been set (and a fresh, unpopulated copy of the form
+      // if one hasn't). If the form was called by drupal_execute(),
+      // however, we'll skip this and let the calling function examine
+      // the resulting $form_state bundle itself.
+      if (!$form['#programmed'] && empty($form_state['rebuild']) && empty($form_state['storage'])) {
+        drupal_redirect_form($form, $form_state['redirect']);
+      }
+    }
+  }
+}
+
+/**
+ * Prepares a structured form array by adding required elements,
+ * executing any hook_form_alter functions, and optionally inserting
+ * a validation token to prevent tampering.
+ *
+ * @param $form_id
+ *   A unique string identifying the form for validation, submission,
+ *   theming, and hook_form_alter functions.
+ * @param $form
+ *   An associative array containing the structure of the form.
+ * @param $form_state
+ *   A keyed array containing the current state of the form. Passed
+ *   in here so that hook_form_alter() calls can use it, as well.
+ */
+function drupal_prepare_form($form_id, &$form, &$form_state) {
+  global $user;
+
+  $form['#type'] = 'form';
+  $form['#programmed'] = isset($form['#post']);
+
+  if (isset($form['#build_id'])) {
+    $form['form_build_id'] = array(
+      '#type' => 'hidden',
+      '#value' => $form['#build_id'],
+      '#id' => $form['#build_id'],
+      '#name' => 'form_build_id',
+    );
+  }
+
+  // Add a token, based on either #token or form_id, to any form displayed to
+  // authenticated users. This ensures that any submitted form was actually
+  // requested previously by the user and protects against cross site request
+  // forgeries.
+  if (isset($form['#token'])) {
+    if ($form['#token'] === FALSE || $user->uid == 0 || $form['#programmed']) {
+      unset($form['#token']);
+    }
+    else {
+      $form['form_token'] = array('#type' => 'token', '#default_value' => drupal_get_token($form['#token']));
+    }
+  }
+  else if (isset($user->uid) && $user->uid && !$form['#programmed']) {
+    $form['#token'] = $form_id;
+    $form['form_token'] = array(
+      '#id' => form_clean_id('edit-'. $form_id .'-form-token'),
+      '#type' => 'token',
+      '#default_value' => drupal_get_token($form['#token']),
+    );
+  }
+
+  if (isset($form_id)) {
+    $form['form_id'] = array(
+      '#type' => 'hidden',
+      '#value' => $form_id,
+      '#id' => form_clean_id("edit-$form_id"),
+    );
+  }
+  if (!isset($form['#id'])) {
+    $form['#id'] = form_clean_id($form_id);
+  }
+
+  $form += _element_info('form');
+
+  if (!isset($form['#validate'])) {
+    if (function_exists($form_id .'_validate')) {
+      $form['#validate'] = array($form_id .'_validate');
+    }
+  }
+
+  if (!isset($form['#submit'])) {
+    if (function_exists($form_id .'_submit')) {
+      // We set submit here so that it can be altered.
+      $form['#submit'] = array($form_id .'_submit');
+    }
+  }
+
+  // Normally, we would call drupal_alter($form_id, $form, $form_state).
+  // However, drupal_alter() normally supports just one byref parameter. Using
+  // the __drupal_alter_by_ref key, we can store any additional parameters
+  // that need to be altered, and they'll be split out into additional params
+  // for the hook_form_alter() implementations.
+  // @todo: Remove this in Drupal 7.
+  $data = &$form;
+  $data['__drupal_alter_by_ref'] = array(&$form_state);
+  drupal_alter('form_'. $form_id, $data);
+
+  // __drupal_alter_by_ref is unset in the drupal_alter() function, we need
+  // to repopulate it to ensure both calls get the data.
+  $data['__drupal_alter_by_ref'] = array(&$form_state);
+  drupal_alter('form', $data, $form_id);
+}
+
+
+/**
+ * Validates user-submitted form data from the $form_state using
+ * the validate functions defined in a structured form array.
+ *
+ * @param $form_id
+ *   A unique string identifying the form for validation, submission,
+ *   theming, and hook_form_alter functions.
+ * @param $form
+ *   An associative array containing the structure of the form.
+ * @param $form_state
+ *   A keyed array containing the current state of the form. The current
+ *   user-submitted data is stored in $form_state['values'], though
+ *   form validation functions are passed an explicit copy of the
+ *   values for the sake of simplicity. Validation handlers can also
+ *   $form_state to pass information on to submit handlers. For example:
+ *     $form_state['data_for_submision'] = $data;
+ *   This technique is useful when validation requires file parsing,
+ *   web service requests, or other expensive requests that should
+ *   not be repeated in the submission step.
+ */
+function drupal_validate_form($form_id, $form, &$form_state) {
+  static $validated_forms = array();
+
+  if (isset($validated_forms[$form_id])) {
+    return;
+  }
+
+  // If the session token was set by drupal_prepare_form(), ensure that it
+  // matches the current user's session.
+  if (isset($form['#token'])) {
+    if (!drupal_valid_token($form_state['values']['form_token'], $form['#token'])) {
+      // Setting this error will cause the form to fail validation.
+      form_set_error('form_token', t('Validation error, please try again. If this error persists, please contact the site administrator.'));
+    }
+  }
+
+  _form_validate($form, $form_state, $form_id);
+  $validated_forms[$form_id] = TRUE;
+}
+
+/**
+ * Renders a structured form array into themed HTML.
+ *
+ * @param $form_id
+ *   A unique string identifying the form for validation, submission,
+ *   theming, and hook_form_alter functions.
+ * @param $form
+ *   An associative array containing the structure of the form.
+ * @return
+ *   A string containing the path of the page to display when processing
+ *   is complete.
+ */
+function drupal_render_form($form_id, &$form) {
+  // Don't override #theme if someone already set it.
+  if (!isset($form['#theme'])) {
+    init_theme();
+    $registry = theme_get_registry();
+    if (isset($registry[$form_id])) {
+      $form['#theme'] = $form_id;
+    }
+  }
+
+  $output = drupal_render($form);
+  return $output;
+}
+
+/**
+ * Redirect the user to a URL after a form has been processed.
+ *
+ * @param $form
+ *   An associative array containing the structure of the form.
+ * @param $redirect
+ *   An optional value containing the destination path to redirect
+ *   to if none is specified by the form.
+ */
+function drupal_redirect_form($form, $redirect = NULL) {
+  $goto = NULL;
+  if (isset($redirect)) {
+    $goto = $redirect;
+  }
+  if ($goto !== FALSE && isset($form['#redirect'])) {
+    $goto = $form['#redirect'];
+  }
+  if (!isset($goto) || ($goto !== FALSE)) {
+    if (isset($goto)) {
+      if (is_array($goto)) {
+        call_user_func_array('drupal_goto', $goto);
+      }
+      else {
+        drupal_goto($goto);
+      }
+    }
+    drupal_goto($_GET['q']);
+  }
+}
+
+/**
+ * Performs validation on form elements. First ensures required fields are
+ * completed, #maxlength is not exceeded, and selected options were in the
+ * list of options given to the user. Then calls user-defined validators.
+ *
+ * @param $elements
+ *   An associative array containing the structure of the form.
+ * @param $form_state
+ *   A keyed array containing the current state of the form. The current
+ *   user-submitted data is stored in $form_state['values'], though
+ *   form validation functions are passed an explicit copy of the
+ *   values for the sake of simplicity. Validation handlers can also
+ *   $form_state to pass information on to submit handlers. For example:
+ *     $form_state['data_for_submision'] = $data;
+ *   This technique is useful when validation requires file parsing,
+ *   web service requests, or other expensive requests that should
+ *   not be repeated in the submission step.
+ * @param $form_id
+ *   A unique string identifying the form for validation, submission,
+ *   theming, and hook_form_alter functions.
+ */
+function _form_validate($elements, &$form_state, $form_id = NULL) {
+  static $complete_form;
+
+  // Also used in the installer, pre-database setup.
+  $t = get_t();
+
+  // Recurse through all children.
+  foreach (element_children($elements) as $key) {
+    if (isset($elements[$key]) && $elements[$key]) {
+      _form_validate($elements[$key], $form_state);
+    }
+  }
+  // Validate the current input.
+  if (!isset($elements['#validated']) || !$elements['#validated']) {
+    if (isset($elements['#needs_validation'])) {
+      // Make sure a value is passed when the field is required.
+      // A simple call to empty() will not cut it here as some fields, like
+      // checkboxes, can return a valid value of '0'. Instead, check the
+      // length if it's a string, and the item count if it's an array.
+      if ($elements['#required'] && (!count($elements['#value']) || (is_string($elements['#value']) && strlen(trim($elements['#value'])) == 0))) {
+        form_error($elements, $t('!name field is required.', array('!name' => $elements['#title'])));
+      }
+
+      // Verify that the value is not longer than #maxlength.
+      if (isset($elements['#maxlength']) && drupal_strlen($elements['#value']) > $elements['#maxlength']) {
+        form_error($elements, $t('!name cannot be longer than %max characters but is currently %length characters long.', array('!name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title'], '%max' => $elements['#maxlength'], '%length' => drupal_strlen($elements['#value']))));
+      }
+
+      if (isset($elements['#options']) && isset($elements['#value'])) {
+        if ($elements['#type'] == 'select') {
+          $options = form_options_flatten($elements['#options']);
+        }
+        else {
+          $options = $elements['#options'];
+        }
+        if (is_array($elements['#value'])) {
+          $value = $elements['#type'] == 'checkboxes' ? array_keys(array_filter($elements['#value'])) : $elements['#value'];
+          foreach ($value as $v) {
+            if (!isset($options[$v])) {
+              form_error($elements, $t('An illegal choice has been detected. Please contact the site administrator.'));
+              watchdog('form', 'Illegal choice %choice in !name element.', array('%choice' => $v, '!name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title']), WATCHDOG_ERROR);
+            }
+          }
+        }
+        elseif (!isset($options[$elements['#value']])) {
+          form_error($elements, $t('An illegal choice has been detected. Please contact the site administrator.'));
+          watchdog('form', 'Illegal choice %choice in %name element.', array('%choice' => $elements['#value'], '%name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title']), WATCHDOG_ERROR);
+        }
+      }
+    }
+
+    // Call user-defined form level validators and store a copy of the full
+    // form so that element-specific validators can examine the entire structure
+    // if necessary.
+    if (isset($form_id)) {
+      form_execute_handlers('validate', $elements, $form_state);
+      $complete_form = $elements;
+    }
+    // Call any element-specific validators. These must act on the element
+    // #value data.
+    elseif (isset($elements['#element_validate'])) {
+      foreach ($elements['#element_validate'] as $function) {
+        if (function_exists($function))  {
+          $function($elements, $form_state, $complete_form);
+        }
+      }
+    }
+    $elements['#validated'] = TRUE;
+  }
+}
+
+/**
+ * A helper function used to execute custom validation and submission
+ * handlers for a given form. Button-specific handlers are checked
+ * first. If none exist, the function falls back to form-level handlers.
+ *
+ * @param $type
+ *   The type of handler to execute. 'validate' or 'submit' are the
+ *   defaults used by Form API.
+ * @param $form
+ *   An associative array containing the structure of the form.
+ * @param $form_state
+ *   A keyed array containing the current state of the form. If the user
+ *   submitted the form by clicking a button with custom handler functions
+ *   defined, those handlers will be stored here.
+ */
+function form_execute_handlers($type, &$form, &$form_state) {
+  $return = FALSE;
+  if (isset($form_state[$type .'_handlers'])) {
+    $handlers = $form_state[$type .'_handlers'];
+  }
+  elseif (isset($form['#'. $type])) {
+    $handlers = $form['#'. $type];
+  }
+  else {
+    $handlers = array();
+  }
+
+  foreach ($handlers as $function) {
+    if (function_exists($function))  {
+      if ($type == 'submit' && ($batch =& batch_get())) {
+        // Some previous _submit handler has set a batch. We store the call
+        // in a special 'control' batch set, for execution at the correct
+        // time during the batch processing workflow.
+        $batch['sets'][] = array('form_submit' => $function);
+      }
+      else {
+        $function($form, $form_state);
+      }
+      $return = TRUE;
+    }
+  }
+  return $return;
+}
+
+/**
+ * File an error against a form element.
+ *
+ * @param $name
+ *   The name of the form element. If the #parents property of your form
+ *   element is array('foo', 'bar', 'baz') then you may set an error on 'foo'
+ *   or 'foo][bar][baz'. Setting an error on 'foo' sets an error for every
+ *   element where the #parents array starts with 'foo'.
+ * @param $message
+ *   The error message to present to the user.
+ * @return
+ *   Never use the return value of this function, use form_get_errors and
+ *   form_get_error instead.
+ */
+function form_set_error($name = NULL, $message = '') {
+  static $form = array();
+  if (isset($name) && !isset($form[$name])) {
+    $form[$name] = $message;
+    if ($message) {
+      drupal_set_message($message, 'error');
+    }
+  }
+  return $form;
+}
+
+/**
+ * Return an associative array of all errors.
+ */
+function form_get_errors() {
+  $form = form_set_error();
+  if (!empty($form)) {
+    return $form;
+  }
+}
+
+/**
+ * Return the error message filed against the form with the specified name.
+ */
+function form_get_error($element) {
+  $form = form_set_error();
+  $key = $element['#parents'][0];
+  if (isset($form[$key])) {
+    return $form[$key];
+  }
+  $key = implode('][', $element['#parents']);
+  if (isset($form[$key])) {
+    return $form[$key];
+  }
+}
+
+/**
+ * Flag an element as having an error.
+ */
+function form_error(&$element, $message = '') {
+  form_set_error(implode('][', $element['#parents']), $message);
+}
+
+/**
+ * Walk through the structured form array, adding any required
+ * properties to each element and mapping the incoming $_POST
+ * data to the proper elements.
+ *
+ * @param $form_id
+ *   A unique string identifying the form for validation, submission,
+ *   theming, and hook_form_alter functions.
+ * @param $form
+ *   An associative array containing the structure of the form.
+ * @param $form_state
+ *   A keyed array containing the current state of the form. In this
+ *   context, it is used to accumulate information about which button
+ *   was clicked when the form was submitted, as well as the sanitized
+ *   $_POST data.
+ */
+function form_builder($form_id, $form, &$form_state) {
+  static $complete_form, $cache;
+
+  // Initialize as unprocessed.
+  $form['#processed'] = FALSE;
+
+  // Use element defaults.
+  if ((!empty($form['#type'])) && ($info = _element_info($form['#type']))) {
+    // Overlay $info onto $form, retaining preexisting keys in $form.
+    $form += $info;
+  }
+
+  if (isset($form['#type']) && $form['#type'] == 'form') {
+    $cache = NULL;
+    $complete_form = $form;
+    if (!empty($form['#programmed'])) {
+      $form_state['submitted'] = TRUE;
+    }
+  }
+
+  if (isset($form['#input']) && $form['#input']) {
+    _form_builder_handle_input_element($form_id, $form, $form_state, $complete_form);
+  }
+  $form['#defaults_loaded'] = TRUE;
+
+  // We start off assuming all form elements are in the correct order.
+  $form['#sorted'] = TRUE;
+
+  // Recurse through all child elements.
+  $count = 0;
+  foreach (element_children($form) as $key) {
+    $form[$key]['#post'] = $form['#post'];
+    $form[$key]['#programmed'] = $form['#programmed'];
+    // Don't squash an existing tree value.
+    if (!isset($form[$key]['#tree'])) {
+      $form[$key]['#tree'] = $form['#tree'];
+    }
+
+    // Deny access to child elements if parent is denied.
+    if (isset($form['#access']) && !$form['#access']) {
+      $form[$key]['#access'] = FALSE;
+    }
+
+    // Don't squash existing parents value.
+    if (!isset($form[$key]['#parents'])) {
+      // Check to see if a tree of child elements is present. If so,
+      // continue down the tree if required.
+      $form[$key]['#parents'] = $form[$key]['#tree'] && $form['#tree'] ? array_merge($form['#parents'], array($key)) : array($key);
+      $array_parents = isset($form['#array_parents']) ? $form['#array_parents'] : array();
+      $array_parents[] = $key;
+      $form[$key]['#array_parents'] = $array_parents;
+    }
+
+    // Assign a decimal placeholder weight to preserve original array order.
+    if (!isset($form[$key]['#weight'])) {
+      $form[$key]['#weight'] = $count/1000;
+    }
+    else {
+      // If one of the child elements has a weight then we will need to sort
+      // later.
+      unset($form['#sorted']);
+    }
+    $form[$key] = form_builder($form_id, $form[$key], $form_state);
+    $count++;
+  }
+
+  // The #after_build flag allows any piece of a form to be altered
+  // after normal input parsing has been completed.
+  if (isset($form['#after_build']) && !isset($form['#after_build_done'])) {
+    foreach ($form['#after_build'] as $function) {
+      $form = $function($form, $form_state);
+      $form['#after_build_done'] = TRUE;
+    }
+  }
+
+  // Now that we've processed everything, we can go back to handle the funky
+  // Internet Explorer button-click scenario.
+  _form_builder_ie_cleanup($form, $form_state);
+
+  // We shoud keep the buttons array until the IE clean up function
+  // has recognized the submit button so the form has been marked
+  // as submitted. If we already know which button was submitted,
+  // we don't need the array.
+  if (!empty($form_state['submitted'])) {
+    unset($form_state['buttons']);
+  }
+
+  // If some callback set #cache, we need to flip a static flag so later it
+  // can be found.
+  if (isset($form['#cache'])) {
+    $cache = $form['#cache'];
+  }
+  // We are on the top form, we can copy back #cache if it's set.
+  if (isset($form['#type']) && $form['#type'] == 'form' && isset($cache)) {
+    $form['#cache'] = TRUE;
+  }
+  return $form;
+}
+
+/**
+ * Populate the #value and #name properties of input elements so they
+ * can be processed and rendered. Also, execute any #process handlers
+ * attached to a specific element.
+ */
+function _form_builder_handle_input_element($form_id, &$form, &$form_state, $complete_form) {
+  if (!isset($form['#name'])) {
+    $name = array_shift($form['#parents']);
+    $form['#name'] = $name;
+    if ($form['#type'] == 'file') {
+      // To make it easier to handle $_FILES in file.inc, we place all
+      // file fields in the 'files' array. Also, we do not support
+      // nested file names.
+      $form['#name'] = 'files['. $form['#name'] .']';
+    }
+    elseif (count($form['#parents'])) {
+      $form['#name'] .= '['. implode('][', $form['#parents']) .']';
+    }
+    array_unshift($form['#parents'], $name);
+  }
+  if (!isset($form['#id'])) {
+    $form['#id'] = form_clean_id('edit-'. implode('-', $form['#parents']));
+  }
+
+  unset($edit);
+  if (!empty($form['#disabled'])) {
+    $form['#attributes']['disabled'] = 'disabled';
+  }
+
+  if (!isset($form['#value']) && !array_key_exists('#value', $form)) {
+    $function = !empty($form['#value_callback']) ? $form['#value_callback'] : 'form_type_'. $form['#type'] .'_value';
+    if (($form['#programmed']) || ((!isset($form['#access']) || $form['#access']) && isset($form['#post']) && (isset($form['#post']['form_id']) && $form['#post']['form_id'] == $form_id))) {
+      $edit = $form['#post'];
+      foreach ($form['#parents'] as $parent) {
+        $edit = isset($edit[$parent]) ? $edit[$parent] : NULL;
+      }
+      if (!$form['#programmed'] || isset($edit)) {
+        // Call #type_value to set the form value;
+        if (function_exists($function)) {
+          $form['#value'] = $function($form, $edit);
+        }
+        if (!isset($form['#value']) && isset($edit)) {
+          $form['#value'] = $edit;
+        }
+      }
+      // Mark all posted values for validation.
+      if (isset($form['#value']) || (isset($form['#required']) && $form['#required'])) {
+        $form['#needs_validation'] = TRUE;
+      }
+    }
+    // Load defaults.
+    if (!isset($form['#value'])) {
+      // Call #type_value without a second argument to request default_value handling.
+      if (function_exists($function)) {
+        $form['#value'] = $function($form);
+      }
+      // Final catch. If we haven't set a value yet, use the explicit default value.
+      // Avoid image buttons (which come with garbage value), so we only get value
+      // for the button actually clicked.
+      if (!isset($form['#value']) && empty($form['#has_garbage_value'])) {
+        $form['#value'] = isset($form['#default_value']) ? $form['#default_value'] : '';
+      }
+    }
+  }
+
+  // Determine which button (if any) was clicked to submit the form.
+  // We compare the incoming values with the buttons defined in the form,
+  // and flag the one that matches. We have to do some funky tricks to
+  // deal with Internet Explorer's handling of single-button forms, though.
+  if (!empty($form['#post']) && isset($form['#executes_submit_callback'])) {
+    // First, accumulate a collection of buttons, divided into two bins:
+    // those that execute full submit callbacks and those that only validate.
+    $button_type = $form['#executes_submit_callback'] ? 'submit' : 'button';
+    $form_state['buttons'][$button_type][] = $form;
+
+    if (_form_button_was_clicked($form)) {
+      $form_state['submitted'] = $form_state['submitted'] || $form['#executes_submit_callback'];
+
+      // In most cases, we want to use form_set_value() to manipulate
+      // the global variables. In this special case, we want to make sure that
+      // the value of this element is listed in $form_variables under 'op'.
+      $form_state['values'][$form['#name']] = $form['#value'];
+      $form_state['clicked_button'] = $form;
+
+      if (isset($form['#validate'])) {
+        $form_state['validate_handlers'] = $form['#validate'];
+      }
+      if (isset($form['#submit'])) {
+        $form_state['submit_handlers'] = $form['#submit'];
+      }
+    }
+  }
+  // Allow for elements to expand to multiple elements, e.g., radios,
+  // checkboxes and files.
+  if (isset($form['#process']) && !$form['#processed']) {
+    foreach ($form['#process'] as $process) {
+      if (function_exists($process)) {
+        $form = $process($form, isset($edit) ? $edit : NULL, $form_state, $complete_form);
+      }
+    }
+    $form['#processed'] = TRUE;
+  }
+  form_set_value($form, $form['#value'], $form_state);
+}
+
+/**
+ * Helper function to handle the sometimes-convoluted logic of button
+ * click detection.
+ *
+ * In Internet Explorer, if ONLY one submit button is present, AND the
+ * enter key is used to submit the form, no form value is sent for it
+ * and we'll never detect a match. That special case is handled by
+ * _form_builder_ie_cleanup().
+ */
+function _form_button_was_clicked($form) {
+  // First detect normal 'vanilla' button clicks. Traditionally, all
+  // standard buttons on a form share the same name (usually 'op'),
+  // and the specific return value is used to determine which was
+  // clicked. This ONLY works as long as $form['#name'] puts the
+  // value at the top level of the tree of $_POST data.
+  if (isset($form['#post'][$form['#name']]) && $form['#post'][$form['#name']] == $form['#value']) {
+    return TRUE;
+  }
+  // When image buttons are clicked, browsers do NOT pass the form element
+  // value in $_POST. Instead they pass an integer representing the
+  // coordinates of the click on the button image. This means that image
+  // buttons MUST have unique $form['#name'] values, but the details of
+  // their $_POST data should be ignored.
+  elseif (!empty($form['#has_garbage_value']) && isset($form['#value']) && $form['#value'] !== '') {
+    return TRUE;
+  }
+  return FALSE;
+}
+
+/**
+ * In IE, if only one submit button is present, AND the enter key is
+ * used to submit the form, no form value is sent for it and our normal
+ * button detection code will never detect a match. We call this
+ * function after all other button-detection is complete to check
+ * for the proper conditions, and treat the single button on the form
+ * as 'clicked' if they are met.
+ */
+function _form_builder_ie_cleanup($form, &$form_state) {
+  // Quick check to make sure we're always looking at the full form
+  // and not a sub-element.
+  if (!empty($form['#type']) && $form['#type'] == 'form') {
+    // If we haven't recognized a submission yet, and there's a single
+    // submit button, we know that we've hit the right conditions. Grab
+    // the first one and treat it as the clicked button.
+    if (empty($form_state['submitted']) && !empty($form_state['buttons']['submit']) && empty($form_state['buttons']['button'])) {
+      $button = $form_state['buttons']['submit'][0];
+
+      // Set up all the $form_state information that would have been
+      // populated had the button been recognized earlier.
+      $form_state['submitted'] = TRUE;
+      $form_state['submit_handlers'] = empty($button['#submit']) ? NULL : $button['#submit'];
+      $form_state['validate_handlers'] = empty($button['#validate']) ? NULL : $button['#validate'];
+      $form_state['values'][$button['#name']] = $button['#value'];
+      $form_state['clicked_button'] = $button;
+    }
+  }
+}
+
+/**
+ * Helper function to determine the value for an image button form element.
+ *
+ * @param $form
+ *   The form element whose value is being populated.
+ * @param $edit
+ *   The incoming POST data to populate the form element. If this is FALSE,
+ *   the element's default value should be returned.
+ * @return
+ *   The data that will appear in the $form_state['values'] collection
+ *   for this element. Return nothing to use the default.
+ */
+function form_type_image_button_value($form, $edit = FALSE) {
+  if ($edit !== FALSE) {
+    if (!empty($edit)) {
+      // If we're dealing with Mozilla or Opera, we're lucky. It will
+      // return a proper value, and we can get on with things.
+      return $form['#return_value'];
+    }
+    else {
+      // Unfortunately, in IE we never get back a proper value for THIS
+      // form element. Instead, we get back two split values: one for the
+      // X and one for the Y coordinates on which the user clicked the
+      // button. We'll find this element in the #post data, and search
+      // in the same spot for its name, with '_x'.
+      $post = $form['#post'];
+      foreach (split('\[', $form['#name']) as $element_name) {
+        // chop off the ] that may exist.
+        if (substr($element_name, -1) == ']') {
+          $element_name = substr($element_name, 0, -1);
+        }
+
+        if (!isset($post[$element_name])) {
+          if (isset($post[$element_name .'_x'])) {
+            return $form['#return_value'];
+          }
+          return NULL;
+        }
+        $post = $post[$element_name];
+      }
+      return $form['#return_value'];
+    }
+  }
+}
+
+/**
+ * Helper function to determine the value for a checkbox form element.
+ *
+ * @param $form
+ *   The form element whose value is being populated.
+ * @param $edit
+ *   The incoming POST data to populate the form element. If this is FALSE,
+ *   the element's default value should be returned.
+ * @return
+ *   The data that will appear in the $form_state['values'] collection
+ *   for this element. Return nothing to use the default.
+ */
+function form_type_checkbox_value($form, $edit = FALSE) {
+  if ($edit !== FALSE) {
+    return !empty($edit) ? $form['#return_value'] : 0;
+  }
+}
+
+/**
+ * Helper function to determine the value for a checkboxes form element.
+ *
+ * @param $form
+ *   The form element whose value is being populated.
+ * @param $edit
+ *   The incoming POST data to populate the form element. If this is FALSE,
+ *   the element's default value should be returned.
+ * @return
+ *   The data that will appear in the $form_state['values'] collection
+ *   for this element. Return nothing to use the default.
+ */
+function form_type_checkboxes_value($form, $edit = FALSE) {
+  if ($edit === FALSE) {
+    $value = array();
+    $form += array('#default_value' => array());
+    foreach ($form['#default_value'] as $key) {
+      $value[$key] = 1;
+    }
+    return $value;
+  }
+  elseif (!isset($edit)) {
+    return array();
+  }
+}
+
+/**
+ * Helper function to determine the value for a password_confirm form
+ * element.
+ *
+ * @param $form
+ *   The form element whose value is being populated.
+ * @param $edit
+ *   The incoming POST data to populate the form element. If this is FALSE,
+ *   the element's default value should be returned.
+ * @return
+ *   The data that will appear in the $form_state['values'] collection
+ *   for this element. Return nothing to use the default.
+ */
+function form_type_password_confirm_value($form, $edit = FALSE) {
+  if ($edit === FALSE) {
+    $form += array('#default_value' => array());
+    return $form['#default_value'] + array('pass1' => '', 'pass2' => '');
+  }
+}
+
+/**
+ * Helper function to determine the value for a select form element.
+ *
+ * @param $form
+ *   The form element whose value is being populated.
+ * @param $edit
+ *   The incoming POST data to populate the form element. If this is FALSE,
+ *   the element's default value should be returned.
+ * @return
+ *   The data that will appear in the $form_state['values'] collection
+ *   for this element. Return nothing to use the default.
+ */
+function form_type_select_value($form, $edit = FALSE) {
+  if ($edit !== FALSE) {
+    if (isset($form['#multiple']) && $form['#multiple']) {
+      return (is_array($edit)) ? drupal_map_assoc($edit) : array();
+    }
+    else {
+      return $edit;
+    }
+  }
+}
+
+/**
+ * Helper function to determine the value for a textfield form element.
+ *
+ * @param $form
+ *   The form element whose value is being populated.
+ * @param $edit
+ *   The incoming POST data to populate the form element. If this is FALSE,
+ *   the element's default value should be returned.
+ * @return
+ *   The data that will appear in the $form_state['values'] collection
+ *   for this element. Return nothing to use the default.
+ */
+function form_type_textfield_value($form, $edit = FALSE) {
+  if ($edit !== FALSE) {
+    // Equate $edit to the form value to ensure it's marked for
+    // validation.
+    return str_replace(array("\r", "\n"), '', $edit);
+  }
+}
+
+/**
+ * Helper function to determine the value for form's token value.
+ *
+ * @param $form
+ *   The form element whose value is being populated.
+ * @param $edit
+ *   The incoming POST data to populate the form element. If this is FALSE,
+ *   the element's default value should be returned.
+ * @return
+ *   The data that will appear in the $form_state['values'] collection
+ *   for this element. Return nothing to use the default.
+ */
+function form_type_token_value($form, $edit = FALSE) {
+  if ($edit !== FALSE) {
+    return (string)$edit;
+  }
+}
+
+/**
+ * Use this function to make changes to form values in the form validate
+ * phase, so they will be available in the submit phase in $form_state.
+ *
+ * Specifically, if $form['#parents'] is array('foo', 'bar')
+ * and $value is 'baz' then this function will make
+ * $form_state['values']['foo']['bar'] to be 'baz'.
+ *
+ * @param $form
+ *   The form item. Keys used: #parents, #value
+ * @param $value
+ *   The value for the form item.
+ */
+function form_set_value($form, $value, &$form_state) {
+  _form_set_value($form_state['values'], $form, $form['#parents'], $value);
+}
+
+/**
+ * Helper function for form_set_value().
+ *
+ * We iterate over $parents and create nested arrays for them
+ * in $form_state['values'] if needed. Then we insert the value into
+ * the right array.
+ */
+function _form_set_value(&$form_values, $form, $parents, $value) {
+  $parent = array_shift($parents);
+  if (empty($parents)) {
+    $form_values[$parent] = $value;
+  }
+  else {
+    if (!isset($form_values[$parent])) {
+      $form_values[$parent] = array();
+    }
+    _form_set_value($form_values[$parent], $form, $parents, $value);
+  }
+}
+
+/**
+ * Retrieve the default properties for the defined element type.
+ */
+function _element_info($type, $refresh = NULL) {
+  static $cache;
+
+  $basic_defaults = array(
+    '#description' => NULL,
+    '#attributes' => array(),
+    '#required' => FALSE,
+    '#tree' => FALSE,
+    '#parents' => array()
+  );
+  if (!isset($cache) || $refresh) {
+    $cache = array();
+    foreach (module_implements('elements') as $module) {
+      $elements = module_invoke($module, 'elements');
+      if (isset($elements) && is_array($elements)) {
+        $cache = array_merge_recursive($cache, $elements);
+      }
+    }
+    if (sizeof($cache)) {
+      foreach ($cache as $element_type => $info) {
+        $cache[$element_type] = array_merge_recursive($basic_defaults, $info);
+      }
+    }
+  }
+
+  return $cache[$type];
+}
+
+function form_options_flatten($array, $reset = TRUE) {
+  static $return;
+
+  if ($reset) {
+    $return = array();
+  }
+
+  foreach ($array as $key => $value) {
+    if (is_object($value)) {
+      form_options_flatten($value->option, FALSE);
+    }
+    else if (is_array($value)) {
+      form_options_flatten($value, FALSE);
+    }
+    else {
+      $return[$key] = 1;
+    }
+  }
+
+  return $return;
+}
+
+/**
+ * Format a dropdown menu or scrolling selection box.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: title, value, options, description, extra, multiple, required
+ * @return
+ *   A themed HTML string representing the form element.
+ *
+ * @ingroup themeable
+ *
+ * It is possible to group options together; to do this, change the format of
+ * $options to an associative array in which the keys are group labels, and the
+ * values are associative arrays in the normal $options format.
+ */
+function theme_select($element) {
+  $select = '';
+  $size = $element['#size'] ? ' size="'. $element['#size'] .'"' : '';
+  _form_set_class($element, array('form-select'));
+  $multiple = $element['#multiple'];
+  return theme('form_element', $element, '<select name="'. $element['#name'] .''. ($multiple ? '[]' : '') .'"'. ($multiple ? ' multiple="multiple" ' : '') . drupal_attributes($element['#attributes']) .' id="'. $element['#id'] .'" '. $size .'>'. form_select_options($element) .'</select>');
+}
+
+function form_select_options($element, $choices = NULL) {
+  if (!isset($choices)) {
+    $choices = $element['#options'];
+  }
+  // array_key_exists() accommodates the rare event where $element['#value'] is NULL.
+  // isset() fails in this situation.
+  $value_valid = isset($element['#value']) || array_key_exists('#value', $element);
+  $value_is_array = is_array($element['#value']);
+  $options = '';
+  foreach ($choices as $key => $choice) {
+    if (is_array($choice)) {
+      $options .= '<optgroup label="'. $key .'">';
+      $options .= form_select_options($element, $choice);
+      $options .= '</optgroup>';
+    }
+    elseif (is_object($choice)) {
+      $options .= form_select_options($element, $choice->option);
+    }
+    else {
+      $key = (string)$key;
+      if ($value_valid && (!$value_is_array && (string)$element['#value'] === $key || ($value_is_array && in_array($key, $element['#value'])))) {
+        $selected = ' selected="selected"';
+      }
+      else {
+        $selected = '';
+      }
+      $options .= '<option value="'. check_plain($key) .'"'. $selected .'>'. check_plain($choice) .'</option>';
+    }
+  }
+  return $options;
+}
+
+/**
+ * Traverses a select element's #option array looking for any values
+ * that hold the given key. Returns an array of indexes that match.
+ *
+ * This function is useful if you need to modify the options that are
+ * already in a form element; for example, to remove choices which are
+ * not valid because of additional filters imposed by another module.
+ * One example might be altering the choices in a taxonomy selector.
+ * To correctly handle the case of a multiple hierarchy taxonomy,
+ * #options arrays can now hold an array of objects, instead of a
+ * direct mapping of keys to labels, so that multiple choices in the
+ * selector can have the same key (and label). This makes it difficult
+ * to manipulate directly, which is why this helper function exists.
+ *
+ * This function does not support optgroups (when the elements of the
+ * #options array are themselves arrays), and will return FALSE if
+ * arrays are found. The caller must either flatten/restore or
+ * manually do their manipulations in this case, since returning the
+ * index is not sufficient, and supporting this would make the
+ * "helper" too complicated and cumbersome to be of any help.
+ *
+ * As usual with functions that can return array() or FALSE, do not
+ * forget to use === and !== if needed.
+ *
+ * @param $element
+ *   The select element to search.
+ * @param $key
+ *   The key to look for.
+ * @return
+ *   An array of indexes that match the given $key. Array will be
+ *   empty if no elements were found. FALSE if optgroups were found.
+ */
+function form_get_options($element, $key) {
+  $keys = array();
+  foreach ($element['#options'] as $index => $choice) {
+    if (is_array($choice)) {
+      return FALSE;
+    }
+    else if (is_object($choice)) {
+      if (isset($choice->option[$key])) {
+        $keys[] = $index;
+      }
+    }
+    else if ($index == $key) {
+      $keys[] = $index;
+    }
+  }
+  return $keys;
+}
+
+/**
+ * Format a group of form items.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: attributes, title, value, description, children, collapsible, collapsed
+ * @return
+ *   A themed HTML string representing the form item group.
+ *
+ * @ingroup themeable
+ */
+function theme_fieldset($element) {
+  if ($element['#collapsible']) {
+    drupal_add_js('misc/collapse.js');
+
+    if (!isset($element['#attributes']['class'])) {
+      $element['#attributes']['class'] = '';
+    }
+
+    $element['#attributes']['class'] .= ' collapsible';
+    if ($element['#collapsed']) {
+      $element['#attributes']['class'] .= ' collapsed';
+    }
+  }
+
+  return '<fieldset'. drupal_attributes($element['#attributes']) .'>'. ($element['#title'] ? '<legend>'. $element['#title'] .'</legend>' : '') . (isset($element['#description']) && $element['#description'] ? '<div class="description">'. $element['#description'] .'</div>' : '') . (!empty($element['#children']) ? $element['#children'] : '') . $element['#value'] ."</fieldset>\n";
+}
+
+/**
+ * Format a radio button.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: required, return_value, value, attributes, title, description
+ * @return
+ *   A themed HTML string representing the form item group.
+ *
+ * @ingroup themeable
+ */
+function theme_radio($element) {
+  _form_set_class($element, array('form-radio'));
+  $output = '<input type="radio" ';
+  $output .= 'name="'. $element['#name'] .'" ';
+  $output .= 'value="'. $element['#return_value'] .'" ';
+  $output .= (check_plain($element['#value']) == $element['#return_value']) ? ' checked="checked" ' : ' ';
+  $output .= drupal_attributes($element['#attributes']) .' />';
+  if (!is_null($element['#title'])) {
+    $output = '<label class="option">'. $output .' '. $element['#title'] .'</label>';
+  }
+
+  unset($element['#title']);
+  return theme('form_element', $element, $output);
+}
+
+/**
+ * Format a set of radio buttons.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: title, value, options, description, required and attributes.
+ * @return
+ *   A themed HTML string representing the radio button set.
+ *
+ * @ingroup themeable
+ */
+function theme_radios($element) {
+  $class = 'form-radios';
+  if (isset($element['#attributes']['class'])) {
+    $class .= ' '. $element['#attributes']['class'];
+  }
+  $element['#children'] = '<div class="'. $class .'">'. (!empty($element['#children']) ? $element['#children'] : '') .'</div>';
+  if ($element['#title'] || $element['#description']) {
+    unset($element['#id']);
+    return theme('form_element', $element, $element['#children']);
+  }
+  else {
+    return $element['#children'];
+  }
+}
+
+/**
+ * Format a password_confirm item.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: title, value, id, required, error.
+ * @return
+ *   A themed HTML string representing the form item.
+ *
+ * @ingroup themeable
+ */
+function theme_password_confirm($element) {
+  return theme('form_element', $element, $element['#children']);
+}
+
+/**
+ * Expand a password_confirm field into two text boxes.
+ */
+function expand_password_confirm($element) {
+  $element['pass1'] =  array(
+    '#type' => 'password',
+    '#title' => t('Password'),
+    '#value' => empty($element['#value']) ? NULL : $element['#value']['pass1'],
+    '#required' => $element['#required'],
+    '#attributes' => array('class' => 'password-field'),
+  );
+  $element['pass2'] =  array(
+    '#type' => 'password',
+    '#title' => t('Confirm password'),
+    '#value' => empty($element['#value']) ? NULL : $element['#value']['pass2'],
+    '#required' => $element['#required'],
+    '#attributes' => array('class' => 'password-confirm'),
+  );
+  $element['#element_validate'] = array('password_confirm_validate');
+  $element['#tree'] = TRUE;
+
+  if (isset($element['#size'])) {
+    $element['pass1']['#size'] = $element['pass2']['#size'] = $element['#size'];
+  }
+
+  return $element;
+}
+
+/**
+ * Validate password_confirm element.
+ */
+function password_confirm_validate($form, &$form_state) {
+  $pass1 = trim($form['pass1']['#value']);
+  if (!empty($pass1)) {
+    $pass2 = trim($form['pass2']['#value']);
+    if ($pass1 != $pass2) {
+      form_error($form, t('The specified passwords do not match.'));
+    }
+  }
+  elseif ($form['#required'] && !empty($form['#post'])) {
+    form_error($form, t('Password field is required.'));
+  }
+
+  // Password field must be converted from a two-element array into a single
+  // string regardless of validation results.
+  form_set_value($form['pass1'], NULL, $form_state);
+  form_set_value($form['pass2'], NULL, $form_state);
+  form_set_value($form, $pass1, $form_state);
+
+  return $form;
+
+}
+
+/**
+ * Format a date selection element.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: title, value, options, description, required and attributes.
+ * @return
+ *   A themed HTML string representing the date selection boxes.
+ *
+ * @ingroup themeable
+ */
+function theme_date($element) {
+  return theme('form_element', $element, '<div class="container-inline">'. $element['#children'] .'</div>');
+}
+
+/**
+ * Roll out a single date element.
+ */
+function expand_date($element) {
+  // Default to current date
+  if (empty($element['#value'])) {
+    $element['#value'] = array('day' => format_date(time(), 'custom', 'j'),
+                            'month' => format_date(time(), 'custom', 'n'),
+                            'year' => format_date(time(), 'custom', 'Y'));
+  }
+
+  $element['#tree'] = TRUE;
+
+  // Determine the order of day, month, year in the site's chosen date format.
+  $format = variable_get('date_format_short', 'm/d/Y - H:i');
+  $sort = array();
+  $sort['day'] = max(strpos($format, 'd'), strpos($format, 'j'));
+  $sort['month'] = max(strpos($format, 'm'), strpos($format, 'M'));
+  $sort['year'] = strpos($format, 'Y');
+  asort($sort);
+  $order = array_keys($sort);
+
+  // Output multi-selector for date.
+  foreach ($order as $type) {
+    switch ($type) {
+      case 'day':
+        $options = drupal_map_assoc(range(1, 31));
+        break;
+      case 'month':
+        $options = drupal_map_assoc(range(1, 12), 'map_month');
+        break;
+      case 'year':
+        $options = drupal_map_assoc(range(1900, 2050));
+        break;
+    }
+    $parents = $element['#parents'];
+    $parents[] = $type;
+    $element[$type] = array(
+      '#type' => 'select',
+      '#value' => $element['#value'][$type],
+      '#attributes' => $element['#attributes'],
+      '#options' => $options,
+    );
+  }
+
+  return $element;
+}
+
+/**
+ * Validates the date type to stop dates like February 30, 2006.
+ */
+function date_validate($form) {
+  if (!checkdate($form['#value']['month'], $form['#value']['day'], $form['#value']['year'])) {
+    form_error($form, t('The specified date is invalid.'));
+  }
+}
+
+/**
+ * Helper function for usage with drupal_map_assoc to display month names.
+ */
+function map_month($month) {
+  return format_date(gmmktime(0, 0, 0, $month, 2, 1970), 'custom', 'M', 0);
+}
+
+/**
+ * If no default value is set for weight select boxes, use 0.
+ */
+function weight_value(&$form) {
+  if (isset($form['#default_value'])) {
+    $form['#value'] = $form['#default_value'];
+  }
+  else {
+    $form['#value'] = 0;
+  }
+}
+
+/**
+ * Roll out a single radios element to a list of radios,
+ * using the options array as index.
+ */
+function expand_radios($element) {
+  if (count($element['#options']) > 0) {
+    foreach ($element['#options'] as $key => $choice) {
+      if (!isset($element[$key])) {
+        // Generate the parents as the autogenerator does, so we will have a
+        // unique id for each radio button.
+        $parents_for_id = array_merge($element['#parents'], array($key));
+        $element[$key] = array(
+          '#type' => 'radio',
+          '#title' => $choice,
+          '#return_value' => check_plain($key),
+          '#default_value' => isset($element['#default_value']) ? $element['#default_value'] : NULL,
+          '#attributes' => $element['#attributes'],
+          '#parents' => $element['#parents'],
+          '#id' => form_clean_id('edit-'. implode('-', $parents_for_id)),
+        );
+      }
+    }
+  }
+  return $element;
+}
+
+/**
+ * Add AHAH information about a form element to the page to communicate with
+ * javascript. If #ahah[path] is set on an element, this additional javascript is
+ * added to the page header to attach the AHAH behaviors. See ahah.js for more
+ * information.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: ahah_event, ahah_path, ahah_wrapper, ahah_parameters,
+ *   ahah_effect.
+ * @return
+ *   None. Additional code is added to the header of the page using
+ *   drupal_add_js.
+ */
+function form_expand_ahah($element) {
+  static $js_added = array();
+  // Add a reasonable default event handler if none specified.
+  if (isset($element['#ahah']['path']) && !isset($element['#ahah']['event'])) {
+    switch ($element['#type']) {
+      case 'submit':
+      case 'button':
+      case 'image_button':
+        // Use the mousedown instead of the click event because form
+        // submission via pressing the enter key triggers a click event on
+        // submit inputs, inappropriately triggering AHAH behaviors.
+        $element['#ahah']['event'] = 'mousedown';
+        // Attach an additional event handler so that AHAH behaviours
+        // can be triggered still via keyboard input.
+        $element['#ahah']['keypress'] = TRUE;
+        break;
+      case 'password':
+      case 'textfield':
+      case 'textarea':
+        $element['#ahah']['event'] = 'blur';
+        break;
+      case 'radio':
+      case 'checkbox':
+      case 'select':
+        $element['#ahah']['event'] = 'change';
+        break;
+    }
+  }
+
+  // Adding the same javascript settings twice will cause a recursion error,
+  // we avoid the problem by checking if the javascript has already been added.
+  if (isset($element['#ahah']['path']) && isset($element['#ahah']['event']) && !isset($js_added[$element['#id']])) {
+    drupal_add_js('misc/jquery.form.js');
+    drupal_add_js('misc/ahah.js');
+
+    $ahah_binding = array(
+      'url'      => url($element['#ahah']['path']),
+      'event'    => $element['#ahah']['event'],
+      'keypress' => empty($element['#ahah']['keypress']) ? NULL : $element['#ahah']['keypress'],
+      'wrapper'  => empty($element['#ahah']['wrapper']) ? NULL : $element['#ahah']['wrapper'],
+      'selector' => empty($element['#ahah']['selector']) ? '#'. $element['#id'] : $element['#ahah']['selector'],
+      'effect'   => empty($element['#ahah']['effect']) ? 'none' : $element['#ahah']['effect'],
+      'method'   => empty($element['#ahah']['method']) ? 'replace' : $element['#ahah']['method'],
+      'progress' => empty($element['#ahah']['progress']) ? array('type' => 'throbber') : $element['#ahah']['progress'],
+      'button'   => isset($element['#executes_submit_callback']) ? array($element['#name'] => $element['#value']) : FALSE,
+    );
+
+    // Convert a simple #ahah[progress] type string into an array.
+    if (is_string($ahah_binding['progress'])) {
+      $ahah_binding['progress'] = array('type' => $ahah_binding['progress']);
+    }
+    // Change progress path to a full url.
+    if (isset($ahah_binding['progress']['path'])) {
+      $ahah_binding['progress']['url'] = url($ahah_binding['progress']['path']);
+    }
+
+    // Add progress.js if we're doing a bar display.
+    if ($ahah_binding['progress']['type'] == 'bar') {
+      drupal_add_js('misc/progress.js');
+    }
+
+    drupal_add_js(array('ahah' => array($element['#id'] => $ahah_binding)), 'setting');
+
+    $js_added[$element['#id']] = TRUE;
+    $element['#cache'] = TRUE;
+  }
+  return $element;
+}
+
+/**
+ * Format a form item.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used:  title, value, description, required, error
+ * @return
+ *   A themed HTML string representing the form item.
+ *
+ * @ingroup themeable
+ */
+function theme_item($element) {
+  return theme('form_element', $element, $element['#value'] . (!empty($element['#children']) ? $element['#children'] : ''));
+}
+
+/**
+ * Format a checkbox.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used:  title, value, return_value, description, required
+ * @return
+ *   A themed HTML string representing the checkbox.
+ *
+ * @ingroup themeable
+ */
+function theme_checkbox($element) {
+  _form_set_class($element, array('form-checkbox'));
+  $checkbox = '<input ';
+  $checkbox .= 'type="checkbox" ';
+  $checkbox .= 'name="'. $element['#name'] .'" ';
+  $checkbox .= 'id="'. $element['#id'] .'" ' ;
+  $checkbox .= 'value="'. $element['#return_value'] .'" ';
+  $checkbox .= $element['#value'] ? ' checked="checked" ' : ' ';
+  $checkbox .= drupal_attributes($element['#attributes']) .' />';
+
+  if (!is_null($element['#title'])) {
+    $checkbox = '<label class="option">'. $checkbox .' '. $element['#title'] .'</label>';
+  }
+
+  unset($element['#title']);
+  return theme('form_element', $element, $checkbox);
+}
+
+/**
+ * Format a set of checkboxes.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ * @return
+ *   A themed HTML string representing the checkbox set.
+ *
+ * @ingroup themeable
+ */
+function theme_checkboxes($element) {
+  $class = 'form-checkboxes';
+  if (isset($element['#attributes']['class'])) {
+    $class .= ' '. $element['#attributes']['class'];
+  }
+  $element['#children'] = '<div class="'. $class .'">'. (!empty($element['#children']) ? $element['#children'] : '') .'</div>';
+  if ($element['#title'] || $element['#description']) {
+    unset($element['#id']);
+    return theme('form_element', $element, $element['#children']);
+  }
+  else {
+    return $element['#children'];
+  }
+}
+
+function expand_checkboxes($element) {
+  $value = is_array($element['#value']) ? $element['#value'] : array();
+  $element['#tree'] = TRUE;
+  if (count($element['#options']) > 0) {
+    if (!isset($element['#default_value']) || $element['#default_value'] == 0) {
+      $element['#default_value'] = array();
+    }
+    foreach ($element['#options'] as $key => $choice) {
+      if (!isset($element[$key])) {
+        $element[$key] = array('#type' => 'checkbox', '#processed' => TRUE, '#title' => $choice, '#return_value' => $key, '#default_value' => isset($value[$key]), '#attributes' => $element['#attributes']);
+      }
+    }
+  }
+  return $element;
+}
+
+/**
+ * Theme a form submit button.
+ *
+ * @ingroup themeable
+ */
+function theme_submit($element) {
+  return theme('button', $element);
+}
+
+/**
+ * Theme a form button.
+ *
+ * @ingroup themeable
+ */
+function theme_button($element) {
+  // Make sure not to overwrite classes.
+  if (isset($element['#attributes']['class'])) {
+    $element['#attributes']['class'] = 'form-'. $element['#button_type'] .' '. $element['#attributes']['class'];
+  }
+  else {
+    $element['#attributes']['class'] = 'form-'. $element['#button_type'];
+  }
+
+  return '<input type="submit" '. (empty($element['#name']) ? '' : 'name="'. $element['#name'] .'" ') .'id="'. $element['#id'] .'" value="'. check_plain($element['#value']) .'" '. drupal_attributes($element['#attributes']) ." />\n";
+}
+
+/**
+ * Theme a form image button.
+ *
+ * @ingroup themeable
+ */
+function theme_image_button($element) {
+  // Make sure not to overwrite classes.
+  if (isset($element['#attributes']['class'])) {
+    $element['#attributes']['class'] = 'form-'. $element['#button_type'] .' '. $element['#attributes']['class'];
+  }
+  else {
+    $element['#attributes']['class'] = 'form-'. $element['#button_type'];
+  }
+
+  return '<input type="image" name="'. $element['#name'] .'" '.
+    (!empty($element['#value']) ? ('value="'. check_plain($element['#value']) .'" ') : '') .
+    'id="'. $element['#id'] .'" '.
+    drupal_attributes($element['#attributes']) .
+    ' src="'. base_path() . $element['#src'] .'" '.
+    (!empty($element['#title']) ? 'alt="'. check_plain($element['#title']) .'" title="'. check_plain($element['#title']) .'" ' : '' ) .
+    "/>\n";
+}
+
+/**
+ * Format a hidden form field.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used:  value, edit
+ * @return
+ *   A themed HTML string representing the hidden form field.
+ *
+ * @ingroup themeable
+ */
+function theme_hidden($element) {
+  return '<input type="hidden" name="'. $element['#name'] .'" id="'. $element['#id'] .'" value="'. check_plain($element['#value']) ."\" ". drupal_attributes($element['#attributes']) ." />\n";
+}
+
+/**
+ * Format a form token.
+ *
+ * @ingroup themeable
+ */
+function theme_token($element) {
+  return theme('hidden', $element);
+}
+
+/**
+ * Format a textfield.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used:  title, value, description, size, maxlength, required, attributes autocomplete_path
+ * @return
+ *   A themed HTML string representing the textfield.
+ *
+ * @ingroup themeable
+ */
+function theme_textfield($element) {
+  $size = empty($element['#size']) ? '' : ' size="'. $element['#size'] .'"';
+  $maxlength = empty($element['#maxlength']) ? '' : ' maxlength="'. $element['#maxlength'] .'"';
+  $class = array('form-text');
+  $extra = '';
+  $output = '';
+
+  if ($element['#autocomplete_path']) {
+    drupal_add_js('misc/autocomplete.js');
+    $class[] = 'form-autocomplete';
+    $extra =  '<input class="autocomplete" type="hidden" id="'. $element['#id'] .'-autocomplete" value="'. check_url(url($element['#autocomplete_path'], array('absolute' => TRUE))) .'" disabled="disabled" />';
+  }
+  _form_set_class($element, $class);
+
+  if (isset($element['#field_prefix'])) {
+    $output .= '<span class="field-prefix">'. $element['#field_prefix'] .'</span> ';
+  }
+
+  $output .= '<input type="text"'. $maxlength .' name="'. $element['#name'] .'" id="'. $element['#id'] .'"'. $size .' value="'. check_plain($element['#value']) .'"'. drupal_attributes($element['#attributes']) .' />';
+
+  if (isset($element['#field_suffix'])) {
+    $output .= ' <span class="field-suffix">'. $element['#field_suffix'] .'</span>';
+  }
+
+  return theme('form_element', $element, $output) . $extra;
+}
+
+/**
+ * Format a form.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: action, method, attributes, children
+ * @return
+ *   A themed HTML string representing the form.
+ *
+ * @ingroup themeable
+ */
+function theme_form($element) {
+  // Anonymous div to satisfy XHTML compliance.
+  $action = $element['#action'] ? 'action="'. check_url($element['#action']) .'" ' : '';
+  return '<form '. $action .' accept-charset="UTF-8" method="'. $element['#method'] .'" id="'. $element['#id'] .'"'. drupal_attributes($element['#attributes']) .">\n<div>". $element['#children'] ."\n</div></form>\n";
+}
+
+/**
+ * Format a textarea.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: title, value, description, rows, cols, required, attributes
+ * @return
+ *   A themed HTML string representing the textarea.
+ *
+ * @ingroup themeable
+ */
+function theme_textarea($element) {
+  $class = array('form-textarea');
+
+  // Add teaser behavior (must come before resizable)
+  if (!empty($element['#teaser'])) {
+    drupal_add_js('misc/teaser.js');
+    // Note: arrays are merged in drupal_get_js().
+    drupal_add_js(array('teaserCheckbox' => array($element['#id'] => $element['#teaser_checkbox'])), 'setting');
+    drupal_add_js(array('teaser' => array($element['#id'] => $element['#teaser'])), 'setting');
+    $class[] = 'teaser';
+  }
+
+  // Add resizable behavior
+  if ($element['#resizable'] !== FALSE) {
+    drupal_add_js('misc/textarea.js');
+    $class[] = 'resizable';
+  }
+
+  _form_set_class($element, $class);
+  return theme('form_element', $element, '<textarea cols="'. $element['#cols'] .'" rows="'. $element['#rows'] .'" name="'. $element['#name'] .'" id="'. $element['#id'] .'" '. drupal_attributes($element['#attributes']) .'>'. check_plain($element['#value']) .'</textarea>');
+}
+
+/**
+ * Format HTML markup for use in forms.
+ *
+ * This is used in more advanced forms, such as theme selection and filter format.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used: value, children.
+ * @return
+ *   A themed HTML string representing the HTML markup.
+ *
+ * @ingroup themeable
+ */
+
+function theme_markup($element) {
+  return (isset($element['#value']) ? $element['#value'] : '') . (isset($element['#children']) ? $element['#children'] : '');
+}
+
+/**
+ * Format a password field.
+ *
+ * @param $element
+ *   An associative array containing the properties of the element.
+ *   Properties used:  title, value, description, size, maxlength, required, attributes
+ * @return
+ *   A themed HTML string representing the form.
+ *
+ * @ingroup themeable
+ */
+function theme_password($element) {
+  $size = $element['#size'] ? ' size="'. $element['#size'] .'" ' : '';
+  $maxlength = $element['#maxlength'] ? ' maxlength="'. $element['#maxlength'] .'" ' : '';
+
+  _form_set_class($element, array('form-text'));
+  $output = '<input type="password" name="'. $element['#name'] .'" id="'. $element['#id'] .'" '. $maxlength . $size . drupal_attributes($element['#attributes']) .' />';
+  return theme('form_element', $element, $output);
+}
+
+/**
+ * Expand weight elements into selects.
+ */
+function process_weight($element) {
+  for ($n = (-1 * $element['#delta']); $n <= $element['#delta']; $n++) {
+    $weights[$n] = $n;
+  }
+  $element['#options'] = $weights;
+  $element['#type'] = 'select';
+  $element['#is_weight'] = TRUE;
+  $element += _element_info('select');
+  return $element;
+}
+
+/**
+ * Format a file upload field.
+ *
+ * @param $title
+ *   The label for the file upload field.
+ * @param $name
+ *   The internal name used to refer to the field.
+ * @param $size
+ *   A measure of the visible size of the field (passed directly to HTML).
+ * @param $description
+ *   Explanatory text to display after the form item.
+ * @param $required
+ *   Whether the user must upload a file to the field.
+ * @return
+ *   A themed HTML string representing the field.
+ *
+ * @ingroup themeable
+ *
+ * For assistance with handling the uploaded file correctly, see the API
+ * provided by file.inc.
+ */
+function theme_file($element) {
+  _form_set_class($element, array('form-file'));
+  return theme('form_element', $element, '<input type="file" name="'. $element['#name'] .'"'. ($element['#attributes'] ? ' '. drupal_attributes($element['#attributes']) : '') .' id="'. $element['#id'] .'" size="'. $element['#size'] ."\" />\n");
+}
+
+/**
+ * Return a themed form element.
+ *
+ * @param element
+ *   An associative array containing the properties of the element.
+ *   Properties used: title, description, id, required
+ * @param $value
+ *   The form element's data.
+ * @return
+ *   A string representing the form element.
+ *
+ * @ingroup themeable
+ */
+function theme_form_element($element, $value) {
+  // This is also used in the installer, pre-database setup.
+  $t = get_t();
+
+  $output = '<div class="form-item"';
+  if (!empty($element['#id'])) {
+    $output .= ' id="'. $element['#id'] .'-wrapper"';
+  }
+  $output .= ">\n";
+  $required = !empty($element['#required']) ? '<span class="form-required" title="'. $t('This field is required.') .'">*</span>' : '';
+
+  if (!empty($element['#title'])) {
+    $title = $element['#title'];
+    if (!empty($element['#id'])) {
+      $output .= ' <label for="'. $element['#id'] .'">'. $t('!title: !required', array('!title' => filter_xss_admin($title), '!required' => $required)) ."</label>\n";
+    }
+    else {
+      $output .= ' <label>'. $t('!title: !required', array('!title' => filter_xss_admin($title), '!required' => $required)) ."</label>\n";
+    }
+  }
+
+  $output .= " $value\n";
+
+  if (!empty($element['#description'])) {
+    $output .= ' <div class="description">'. $element['#description'] ."</div>\n";
+  }
+
+  $output .= "</div>\n";
+
+  return $output;
+}
+
+/**
+ * Sets a form element's class attribute.
+ *
+ * Adds 'required' and 'error' classes as needed.
+ *
+ * @param &$element
+ *   The form element.
+ * @param $name
+ *   Array of new class names to be added.
+ */
+function _form_set_class(&$element, $class = array()) {
+  if ($element['#required']) {
+    $class[] = 'required';
+  }
+  if (form_get_error($element)) {
+    $class[] = 'error';
+  }
+  if (isset($element['#attributes']['class'])) {
+    $class[] = $element['#attributes']['class'];
+  }
+  $element['#attributes']['class'] = implode(' ', $class);
+}
+
+/**
+ * Prepare an HTML ID attribute string for a form item.
+ *
+ * Remove invalid characters and guarantee uniqueness.
+ *
+ * @param $id
+ *   The ID to clean.
+ * @param $flush
+ *   If set to TRUE, the function will flush and reset the static array
+ *   which is built to test the uniqueness of element IDs. This is only
+ *   used if a form has completed the validation process. This parameter
+ *   should never be set to TRUE if this function is being called to
+ *   assign an ID to the #ID element.
+ * @return
+ *   The cleaned ID.
+ */
+function form_clean_id($id = NULL, $flush = FALSE) {
+  static $seen_ids = array();
+
+  if ($flush) {
+    $seen_ids = array();
+    return;
+  }
+  $id = str_replace(array('][', '_', ' '), '-', $id);
+
+  // Ensure IDs are unique. The first occurrence is held but left alone.
+  // Subsequent occurrences get a number appended to them. This incrementing
+  // will almost certainly break code that relies on explicit HTML IDs in
+  // forms that appear more than once on the page, but the alternative is
+  // outputting duplicate IDs, which would break JS code and XHTML
+  // validity anyways. For now, it's an acceptable stopgap solution.
+  if (isset($seen_ids[$id])) {
+    $id = $id .'-'. $seen_ids[$id]++;
+  }
+  else {
+    $seen_ids[$id] = 1;
+  }
+
+  return $id;
+}
+
+/**
+ * @} End of "defgroup form_api".
+ */
+
+/**
+ * @defgroup batch Batch operations
+ * @{
+ * Functions allowing forms processing to be spread out over several page
+ * requests, thus ensuring that the processing does not get interrupted
+ * because of a PHP timeout, while allowing the user to receive feedback
+ * on the progress of the ongoing operations.
+ *
+ * The API is primarily designed to integrate nicely with the Form API
+ * workflow, but can also be used by non-FAPI scripts (like update.php)
+ * or even simple page callbacks (which should probably be used sparingly).
+ *
+ * Example:
+ * @code
+ * $batch = array(
+ *   'title' => t('Exporting'),
+ *   'operations' => array(
+ *     array('my_function_1', array($account->uid, 'story')),
+ *     array('my_function_2', array()),
+ *   ),
+ *   'finished' => 'my_finished_callback',
+ * );
+ * batch_set($batch);
+ * // only needed if not inside a form _submit handler :
+ * batch_process();
+ * @endcode
+ *
+ * Sample batch operations:
+ * @code
+ * // Simple and artificial: load a node of a given type for a given user
+ * function my_function_1($uid, $type, &$context) {
+ *   // The $context array gathers batch context information about the execution (read),
+ *   // as well as 'return values' for the current operation (write)
+ *   // The following keys are provided :
+ *   // 'results' (read / write): The array of results gathered so far by
+ *   //   the batch processing, for the current operation to append its own.
+ *   // 'message' (write): A text message displayed in the progress page.
+ *   // The following keys allow for multi-step operations :
+ *   // 'sandbox' (read / write): An array that can be freely used to
+ *   //   store persistent data between iterations. It is recommended to
+ *   //   use this instead of $_SESSION, which is unsafe if the user
+ *   //   continues browsing in a separate window while the batch is processing.
+ *   // 'finished' (write): A float number between 0 and 1 informing
+ *   //   the processing engine of the completion level for the operation.
+ *   //   1 (or no value explicitly set) means the operation is finished
+ *   //   and the batch processing can continue to the next operation.
+ *
+ *   $node = node_load(array('uid' => $uid, 'type' => $type));
+ *   $context['results'][] = $node->nid .' : '. $node->title;
+ *   $context['message'] = $node->title;
+ * }
+ *
+ * // More advanced example: multi-step operation - load all nodes, five by five
+ * function my_function_2(&$context) {
+ *   if (empty($context['sandbox'])) {
+ *     $context['sandbox']['progress'] = 0;
+ *     $context['sandbox']['current_node'] = 0;
+ *     $context['sandbox']['max'] = db_result(db_query('SELECT COUNT(DISTINCT nid) FROM {node}'));
+ *   }
+ *   $limit = 5;
+ *   $result = db_query_range("SELECT nid FROM {node} WHERE nid > %d ORDER BY nid ASC", $context['sandbox']['current_node'], 0, $limit);
+ *   while ($row = db_fetch_array($result)) {
+ *     $node = node_load($row['nid'], NULL, TRUE);
+ *     $context['results'][] = $node->nid .' : '. $node->title;
+ *     $context['sandbox']['progress']++;
+ *     $context['sandbox']['current_node'] = $node->nid;
+ *     $context['message'] = $node->title;
+ *   }
+ *   if ($context['sandbox']['progress'] != $context['sandbox']['max']) {
+ *     $context['finished'] = $context['sandbox']['progress'] / $context['sandbox']['max'];
+ *   }
+ * }
+ * @endcode
+ *
+ * Sample 'finished' callback:
+ * @code
+ * function batch_test_finished($success, $results, $operations) {
+ *   if ($success) {
+ *     $message = format_plural(count($results), 'One post processed.', '@count posts processed.');
+ *   }
+ *   else {
+ *     $message = t('Finished with an error.');
+ *   }
+ *   drupal_set_message($message);
+ *   // Providing data for the redirected page is done through $_SESSION.
+ *   foreach ($results as $result) {
+ *     $items[] = t('Loaded node %title.', array('%title' => $result));
+ *   }
+ *   $_SESSION['my_batch_results'] = $items;
+ * }
+ * @endcode
+ */
+
+/**
+ * Open a new batch.
+ *
+ * @param $batch
+ *   An array defining the batch. The following keys can be used:
+ *     'operations': an array of function calls to be performed.
+ *        Example:
+ *        @code
+ *        array(
+ *          array('my_function_1', array($arg1)),
+ *          array('my_function_2', array($arg2_1, $arg2_2)),
+ *        )
+ *        @endcode
+ *     All the other values below are optional.
+ *     batch_init() provides default values for the messages.
+ *     'title': title for the progress page.
+ *       Defaults to t('Processing').
+ *     'init_message': message displayed while the processing is initialized.
+ *       Defaults to t('Initializing.').
+ *     'progress_message': message displayed while processing the batch.
+ *       Available placeholders are @current, @remaining, @total and @percent.
+ *       Defaults to t('Remaining @remaining of @total.').
+ *     'error_message': message displayed if an error occurred while processing
+ *       the batch.
+ *       Defaults to t('An error has occurred.').
+ *     'finished': the name of a function to be executed after the batch has
+ *       completed. This should be used to perform any result massaging that
+ *       may be needed, and possibly save data in $_SESSION for display after
+ *       final page redirection.
+ *     'file': the path to the file containing the definitions of the
+ *       'operations' and 'finished' functions, for instance if they don't
+ *       reside in the original '.module' file. The path should be relative to
+ *       the base_path(), and thus should be built using drupal_get_path().
+ *
+ * Operations are added as new batch sets. Batch sets are used to ensure
+ * clean code independence, ensuring that several batches submitted by
+ * different parts of the code (core / contrib modules) can be processed
+ * correctly while not interfering or having to cope with each other. Each
+ * batch set gets to specify his own UI messages, operates on its own set
+ * of operations and results, and triggers its own 'finished' callback.
+ * Batch sets are processed sequentially, with the progress bar starting
+ * fresh for every new set.
+ */
+function batch_set($batch_definition) {
+  if ($batch_definition) {
+    $batch =& batch_get();
+    // Initialize the batch
+    if (empty($batch)) {
+      $batch = array(
+        'sets' => array(),
+      );
+    }
+
+    $init = array(
+      'sandbox' => array(),
+      'results' => array(),
+      'success' => FALSE,
+    );
+    // Use get_t() to allow batches at install time.
+    $t = get_t();
+    $defaults = array(
+      'title' => $t('Processing'),
+      'init_message' => $t('Initializing.'),
+      'progress_message' => $t('Remaining @remaining of @total.'),
+      'error_message' => $t('An error has occurred.'),
+    );
+    $batch_set = $init + $batch_definition + $defaults;
+
+    // Tweak init_message to avoid the bottom of the page flickering down after init phase.
+    $batch_set['init_message'] .= '<br/>&nbsp;';
+    $batch_set['total'] = count($batch_set['operations']);
+
+    // If the batch is being processed (meaning we are executing a stored submit handler),
+    // insert the new set after the current one.
+    if (isset($batch['current_set'])) {
+      // array_insert does not exist...
+      $slice1 = array_slice($batch['sets'], 0, $batch['current_set'] + 1);
+      $slice2 = array_slice($batch['sets'], $batch['current_set'] + 1);
+      $batch['sets'] = array_merge($slice1, array($batch_set), $slice2);
+    }
+    else {
+      $batch['sets'][] = $batch_set;
+    }
+  }
+}
+
+/**
+ * Process the batch.
+ *
+ * Unless the batch has been marked with 'progressive' = FALSE, the function
+ * issues a drupal_goto and thus ends page execution.
+ *
+ * This function is not needed in form submit handlers; Form API takes care
+ * of batches that were set during form submission.
+ *
+ * @param $redirect
+ *   (optional) Path to redirect to when the batch has finished processing.
+ * @param $url
+ *   (optional - should only be used for separate scripts like update.php)
+ *   URL of the batch processing page.
+ */
+function batch_process($redirect = NULL, $url = NULL) {
+  $batch =& batch_get();
+
+  if (isset($batch)) {
+    // Add process information
+    $url = isset($url) ? $url : 'batch';
+    $process_info = array(
+      'current_set' => 0,
+      'progressive' => TRUE,
+      'url' => isset($url) ? $url : 'batch',
+      'source_page' => $_GET['q'],
+      'redirect' => $redirect,
+    );
+    $batch += $process_info;
+
+    if ($batch['progressive']) {
+      // Clear the way for the drupal_goto redirection to the batch processing
+      // page, by saving and unsetting the 'destination' if any, on both places
+      // drupal_goto looks for it.
+      if (isset($_REQUEST['destination'])) {
+        $batch['destination'] = $_REQUEST['destination'];
+        unset($_REQUEST['destination']);
+      }
+      elseif (isset($_REQUEST['edit']['destination'])) {
+        $batch['destination'] = $_REQUEST['edit']['destination'];
+        unset($_REQUEST['edit']['destination']);
+      }
+
+      // Initiate db storage in order to get a batch id. We have to provide
+      // at least an empty string for the (not null) 'token' column.
+      db_query("INSERT INTO {batch} (token, timestamp) VALUES ('', %d)", time());
+      $batch['id'] = db_last_insert_id('batch', 'bid');
+
+      // Now that we have a batch id, we can generate the redirection link in
+      // the generic error message.
+      $t = get_t();
+      $batch['error_message'] = $t('Please continue to <a href="@error_url">the error page</a>', array('@error_url' => url($url, array('query' => array('id' => $batch['id'], 'op' => 'finished')))));
+
+      // Actually store the batch data and the token generated form the batch id.
+      db_query("UPDATE {batch} SET token = '%s', batch = '%s' WHERE bid = %d", drupal_get_token($batch['id']), serialize($batch), $batch['id']);
+
+      drupal_goto($batch['url'], 'op=start&id='. $batch['id']);
+    }
+    else {
+      // Non-progressive execution: bypass the whole progressbar workflow
+      // and execute the batch in one pass.
+      require_once './includes/batch.inc';
+      _batch_process();
+    }
+  }
+}
+
+/**
+ * Retrieve the current batch.
+ */
+function &batch_get() {
+  static $batch = array();
+  return $batch;
+}
+
+/**
+ * @} End of "defgroup batch".
+ */