drupal/includes/form.inc

<?php
// $Id$

/**
 * @defgroup form 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:
 *
 * // Display the user registration form.
 * $output = drupal_get_form('user_register');
 *
 * 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/HEAD/file/developer/topics/forms_api_reference.html reference @endlink
 * and the @link http://api.drupal.org/api/HEAD/file/developer/topics/forms_api.html quickstart guide. @endlink
 */

/**
 * Retrieves a form from a builder function, passes it on for
 * processing, and renders the form or redirects to its destination
 * as appropriate. In multi-step form scenarios, it handles properly
 * processing the values using the previous step's form definition,
 * then rendering the requested step for display.
 *
 * @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 $form_id values to the proper form building function. Examples
 *   may be found in node_forms(), search_forms(), and user_forms().
 * @param ...
 *   Any additional arguments needed by the form building function.
 * @return
 *   The rendered form.
 */
function drupal_get_form($form_id) {
  // In multi-step form scenarios, the incoming $_POST values are not
  // necessarily intended for the current form. We need to build
  // a copy of the previously built form for validation and processing,
  // then go on to the one that was requested if everything works.

  $form_build_id = md5(mt_rand());
  if (isset($_POST['form_build_id']) && isset($_SESSION['form'][$_POST['form_build_id']]['args']) && $_POST['form_id'] == $form_id) {
    // There's a previously stored multi-step form. We should handle
    // IT first.
    $stored = TRUE;
    $args = $_SESSION['form'][$_POST['form_build_id']]['args'];
    $form = call_user_func_array('drupal_retrieve_form', $args);
    $form['#build_id'] = $_POST['form_build_id'];
  }
  else {
    // We're coming in fresh; build things as they would be. If the
    // form's #multistep flag is set, store the build parameters so
    // the same form can be reconstituted for validation.
    $args = func_get_args();
    $form = call_user_func_array('drupal_retrieve_form', $args);
    if (isset($form['#multistep']) && $form['#multistep']) {
      // Clean up old multistep form session data.
      _drupal_clean_form_sessions();
      $_SESSION['form'][$form_build_id] = array('timestamp' => time(), 'args' => $args);
      $form['#build_id'] = $form_build_id;
    }
    $stored = FALSE;
  }

  // Process the form, submit it, and store any errors if necessary.
  drupal_process_form($args[0], $form);

  if ($stored && !form_get_errors()) {
    // If it's a stored form and there were no errors, we processed the
    // stored form successfully. Now we need to build the form that was
    // actually requested. We always pass in the current $_POST values
    // to the builder function, as values from one stage of a multistep
    // form can determine how subsequent steps are displayed.
    $args = func_get_args();
    $args[] = $_POST;
    $form = call_user_func_array('drupal_retrieve_form', $args);
    unset($_SESSION['form'][$_POST['form_build_id']]);
    if (isset($form['#multistep']) && $form['#multistep']) {
      $_SESSION['form'][$form_build_id] = array('timestamp' => time(), 'args' => $args);
      $form['#build_id'] = $form_build_id;
    }
    drupal_prepare_form($args[0], $form);
  }

  return drupal_render_form($args[0], $form);
}


/**
 * Remove form information that's at least a day old from the
 * $_SESSION['form'] array.
 */
function _drupal_clean_form_sessions() {
  if (isset($_SESSION['form'])) {
    foreach ($_SESSION['form'] as $build_id => $data) {
      if ($data['timestamp'] < (time() - 84600)) {
        unset($_SESSION['form'][$build_id]);
      }
    }
  }
}


/**
 * Retrieves a form using a form_id, populates it with $form_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 building function. Examples
 *   may be found in node_forms(), search_forms(), and user_forms().
 * @param $form_values
 *   An array of values mirroring the values returned by a given form
 *   when it is submitted by a user.
 * @param ...
 *   Any additional arguments needed by the form building function.
 * @return
 *   Any form validation errors encountered.
 *
 * For example:
 *
 * // register a new user
 * $values['name'] = 'robo-user';
 * $values['mail'] = 'robouser@example.com';
 * $values['pass'] = 'password';
 * drupal_execute('user_register', $values);
 *
 * // Create a new node
 * $node = array('type' => 'story');
 * $values['title'] = 'My node';
 * $values['body'] = 'This is the body text!';
 * $values['name'] = 'robo-user';
 * drupal_execute('story_node_form', $values, $node);
 */
function drupal_execute($form_id, $form_values) {
  $args = func_get_args();

  $form_id = array_shift($args);
  $form_values = array_shift($args);
  array_unshift($args, $form_id);

  if (isset($form_values)) {
    $form = call_user_func_array('drupal_retrieve_form', $args);
    $form['#post'] = $form_values;
    return drupal_process_form($form_id, $form);
  }
}

/**
 * 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 $form_id values to the proper form building function.
 * @param ...
 *   Any additional arguments needed by the form building function.
 */
function drupal_retrieve_form($form_id) {
  static $forms;

  // We save two copies of the incoming arguments: one for modules to use
  // when mapping form ids to builder functions, and another to pass to
  // the builder function itself. We shift out the first argument -- the
  // $form_id itself -- from the list to pass into the builder function,
  // since it's already known.
  $args = func_get_args();
  $saved_args = $args;
  array_shift($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 builder function,
    // such as the node editing form, modules can implement hook_forms(). It
    // maps one or more form_ids to the correct builder 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', $saved_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'];
    }
  }
  // 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 $form
 *   An associative array containing the structure of the form.
 * @return
 *   The path to redirect the user to upon completion.
 */
function drupal_process_form($form_id, &$form) {
  global $form_values, $form_submitted, $user, $form_button_counter;
  static $saved_globals = array();
  // In some scenarios, this function can be called recursively. Pushing any pre-existing
  // $form_values and form submission data lets us start fresh without clobbering work done
  // in earlier recursive calls.
  array_push($saved_globals, array($form_values, $form_submitted, $form_button_counter));

  $form_values = array();
  $form_submitted = FALSE;
  $form_button_counter = array(0, 0);

  drupal_prepare_form($form_id, $form);
  if (($form['#programmed']) || (!empty($_POST) && (($_POST['form_id'] == $form_id)))) {
    drupal_validate_form($form_id, $form);
    // IE does not send a button value when there is only one submit button (and no non-submit buttons)
    // and you submit by pressing enter.
    // In that case we accept a submission without button values.
    if ((($form['#programmed']) || $form_submitted || (!$form_button_counter[0] && $form_button_counter[1])) && !form_get_errors()) {
      $redirect = drupal_submit_form($form_id, $form);
      if ($batch =& batch_get()) {
        $batch['progressive'] = !$form['#programmed'];
        batch_process();
        // Progressive batch processing redirects to the progress page.
        // Execution continues only if programmed form.
      }
      if (!$form['#programmed']) {
        drupal_redirect_form($form, $redirect);
      }
    }
  }

  // We've finished calling functions that alter the global values, so we can
  // restore the ones that were there before this function was called.
  list($form_values, $form_submitted, $form_button_counter) = array_pop($saved_globals);
  if (isset($redirect)) {
    return $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 $form
 *   An associative array containing the structure of the form.
 */
function drupal_prepare_form($form_id, &$form) {
  global $user;

  $form['#type'] = 'form';
  if (!isset($form['#skip_duplicate_check'])) {
    $form['#skip_duplicate_check'] = FALSE;
  }

  if (!isset($form['#post'])) {
    $form['#post'] = $_POST;
    $form['#programmed'] = FALSE;
  }
  else {
    $form['#programmed'] = TRUE;
  }

  // In multi-step form scenarios, this id is used to identify
  // a unique instance of a particular form for retrieval.
  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' => array());
    }
  }

  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' => array());
    }
  }

  drupal_alter('form', $form, $form_id);

  $form = form_builder($form_id, $form);
}


/**
 * Validates user-submitted form data from a global variable 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 $form
 *   An associative array containing the structure of the form.
 *
 */
function drupal_validate_form($form_id, $form) {
  global $form_values;
  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_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.'));
    }
  }

  if (!$form['#programmed'] && !$form['#skip_duplicate_check'] && isset($_SESSION['last_submitted']['hash']) && $_SESSION['last_submitted']['hash'] == md5(serialize($form['form_id']['#post']))) {
    // This is a repeat submission.
    drupal_redirect_form(NULL, $_SESSION['last_submitted']['destination']);
  }

  _form_validate($form, $form_id);
  $validated_forms[$form_id] = TRUE;
}

/**
 * Processes user-submitted form data from a global variable using
 * the submit 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 $form
 *   An associative array containing the structure of the form.
 * @return
 *   A string containing the path of the page to display when processing
 *   is complete.
 *
 */
function drupal_submit_form($form_id, $form) {
  global $form_values;
  $default_args = array($form_id, &$form_values);
  $submitted = FALSE;
  $goto = NULL;

  if (isset($form['#submit'])) {
    foreach ($form['#submit'] as $function => $args) {
      if (function_exists($function)) {
        $args = array_merge($default_args, (array) $args);
        // Since we can only redirect to one page, only the last redirect
        // will work.
        if ($batch =& batch_get()) {
          // Some previous _submit callback 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.
          $batch['sets'][] = array('form submit' => array($function, $args));
        }
        else {
          $redirect = call_user_func_array($function, $args);
          if ($batch =& batch_get()) {
            // The _submit callback has opened a batch: store the needed form info.
            $batch['form_redirect'] = isset($form['#redirect']) ? $form['#redirect'] : NULL;
          }
        }
        $submitted = TRUE;
        if (isset($redirect)) {
          $goto = $redirect;
        }
      }
    }
  }
  // Successful submit. Hash this form's POST and store the hash in the
  // session. We'll use this hash later whenever this user submits another
  // form to make sure no identical forms get submitted twice.
  if ($submitted && !$form['#skip_duplicate_check']) {
    $_SESSION['last_submitted'] = array('destination' => $goto, 'hash' => md5(serialize($form['form_id']['#post'])));
  }

  if (isset($goto)) {
    return $goto;
  }
}

/**
 * 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;
    }
  }

  if (isset($form['#pre_render'])) {
    foreach ($form['#pre_render'] as $function) {
      if (function_exists($function)) {
        $function($form_id, $form);
      }
    }
  }

  $output = drupal_render($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 $redirect
 *   An optional string containing the destination path to redirect
 *   to if none is specified by the form.
 *
 */
function drupal_redirect_form($form, $redirect = NULL) {
  if (isset($redirect)) {
    $goto = $redirect;
  }
  if (isset($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 $form_id
 *   A unique string identifying the form for validation, submission,
 *   theming, and hook_form_alter functions.
 */
function _form_validate($elements, $form_id = NULL) {
  // Recurse through all children.
  foreach (element_children($elements) as $key) {
    if (isset($elements[$key]) && $elements[$key]) {
      _form_validate($elements[$key]);
    }
  }
  /* Validate the current input */
  if (!isset($elements['#validated']) || !$elements['#validated']) {
    if (isset($elements['#needs_validation'])) {
      // An empty textfield returns '' so we use empty(). An empty checkbox
      // and a textfield could return '0' and empty('0') returns TRUE so we
      // need a special check for the '0' string.
      if ($elements['#required'] && empty($elements['#value']) && $elements['#value'] !== '0') {
        form_error($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']))));
      }

       // Add legal choice check if element has #options. Can be skipped, but
       // then you must validate your own element.
      if (isset($elements['#options']) && isset($elements['#value']) && !isset($elements['#DANGEROUS_SKIP_CHECK'])) {
        if ($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 validators.
    if (isset($elements['#validate'])) {
      foreach ($elements['#validate'] as $function => $args) {
        $args = array_merge(array($elements), $args);
        // For the full form we hand over a copy of $form_values.
        if (isset($form_id)) {
          $args = array_merge(array($form_id, $GLOBALS['form_values']), $args);
        }
        if (function_exists($function))  {
          call_user_func_array($function, $args);
        }
      }
    }
    $elements['#validated'] = TRUE;
  }
}

/**
 * File an error against a form element. If the name of the element is
 * edit[foo][bar] then you may pass either foo or foo][bar as $name
 * foo will set an error for all its children.
 */
function form_set_error($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 = '') {
  $element['#error'] = TRUE;
  form_set_error(implode('][', $element['#parents']), $message);
}

/**
 * Adds some required properties to each form element, which are used
 * internally in the form API. This function also automatically assigns
 * the value property from the $edit array, provided the element doesn't
 * already have an assigned value.
 *
 * @param $form_id
 *   A unique string identifying the form for validation, submission,
 *   theming, and hook_form_alter functions.
 * @param $form
 *   An associative array containing the structure of the form.
 */
function form_builder($form_id, $form) {
  global $form_values, $form_submitted, $form_button_counter;

  // 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['#input']) && $form['#input']) {
    if (!isset($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']));
    }

    if (isset($form['#disabled']) && $form['#disabled']) {
      $form['#attributes']['disabled'] = 'disabled';
    }

    if (!isset($form['#value']) && !array_key_exists('#value', $form)) {
      if (($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)) {
          switch ($form['#type']) {
            case 'checkbox':
              $form['#value'] = !empty($edit) ? $form['#return_value'] : 0;
              break;

            case 'select':
              if (isset($form['#multiple']) && $form['#multiple']) {
                if (isset($edit) && is_array($edit)) {
                  $form['#value'] = drupal_map_assoc($edit);
                }
                else {
                  $form['#value'] = array();
                }
              }
              elseif (isset($edit)) {
                $form['#value'] = $edit;
              }
              break;

            case 'textfield':
              if (isset($edit)) {
                // Equate $edit to the form value to ensure it's marked for
                // validation.
                $edit = str_replace(array("\r", "\n"), '', $edit);
                $form['#value'] = $edit;
              }
              break;

            case 'token':
              $form['#value'] = (string)$edit;
              break;

            default:
              if (isset($edit)) {
                $form['#value'] = $edit;
              }
          }
          // Mark all posted values for validation.
          if ((isset($form['#value']) && $form['#value'] === $edit) || (isset($form['#required']) && $form['#required'])) {
            $form['#needs_validation'] = TRUE;
          }
        }
      }
      if (!isset($form['#value'])) {
        $function = $form['#type'] .'_value';
        if (function_exists($function)) {
          $function($form);
        }
        else {
          $form['#value'] = isset($form['#default_value']) ? $form['#default_value'] : '';
        }
      }
    }
    if (isset($form['#executes_submit_callback'])) {
      // Count submit and non-submit buttons.
      $form_button_counter[$form['#executes_submit_callback']]++;
      // See if a submit button was pressed.
      if (isset($form['#post'][$form['#name']]) && $form['#post'][$form['#name']] == $form['#value']) {
        $form_submitted = $form_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'.
        $form_values[$form['#name']] = $form['#value'];
      }
    }
  }

  // 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 => $args) {
      if (function_exists($process)) {
        $args = array_merge(array($form), array(isset($edit) ? $edit : NULL), $args);
        $form = call_user_func_array($process, $args);
      }
    }
    $form['#processed'] = TRUE;
  }

  // Set the $form_values key that gets passed to validate and submit.
  // We call this after #process gets called so that #process has a
  // chance to update #value if desired.
  if (isset($form['#input']) && $form['#input']) {
    form_set_value($form, $form['#value']);
  }

  // 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);
    }

    // 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]);
    $count++;
  }

  if (isset($form['#after_build']) && !isset($form['#after_build_done'])) {
    foreach ($form['#after_build'] as $function) {
      if (function_exists($function)) {
        $form = $function($form, $form_values);
      }
    }
    $form['#after_build_done'] = TRUE;
  }

  return $form;
}

/**
 * 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_values.
 *
 * Specifically, if $form['#parents'] is array('foo', 'bar')
 * and $value is 'baz' then this function will make
 * $form_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) {
  global $form_values;
  _form_set_value($form_values, $form, $form['#parents'], $value);
}

/**
 * Helper function for form_set_value().
 *
 * We iterate over $parents and create nested arrays for them
 * in $form_values if needed. Then we insert the value into
 * the right array.
 */
function _form_set_value(&$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);
  }
  return $form;
}

/**
 * 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.
 *
 * 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="'. $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 $element
 *   An associative array containing the properties of the element.
 *   Properties used: attributes, title, value, description, children, collapsible, collapsed
 * @return
 *   A themed HTML string representing the form item group.
 */
function theme_fieldset($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 $element
 *   An associative array containing the properties of the element.
 *   Properties used: required, return_value, value, attributes, title, description
 * @return
 *   A themed HTML string representing the form item group.
 */
function theme_radio($element) {
  _form_set_class($element, array('form-radio'));
  $output = '<input type="radio" ';
  $output .= 'name="'. $element['#name'] .'" ';
  $output .= 'value="'. $element['#return_value'] .'" ';
  $output .= ($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 $element
 *   An associative array containing the properties of the element.
 *   Properties used: title, value, options, description, required and attributes.
 * @return
 *   A themed HTML string representing the radio button set.
 */
function theme_radios($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 $element
 *   An associative array containing the properties of the element.
 *   Properties used: title, value, id, required, error.
 * @return
 *   A themed HTML string representing the form item.
 */
function theme_password_confirm($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' => $element['#value']['pass1'],
  );
  $element['pass2'] =  array(
    '#type' => 'password',
    '#title' => t('Confirm password'),
    '#value' => $element['#value']['pass2'],
  );
  $element['#validate'] = array('password_confirm_validate' => array());
  $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) {
  $pass1 = trim($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($form['pass1'], NULL);
  form_set_value($form['pass2'], NULL);
  form_set_value($form, $pass1);

  return $form;
}

/**
 * Format a date selection element.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used: title, value, options, description, required and attributes.
 * @return
 *   A themed HTML string representing the date selection boxes.
 */
function theme_date($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);
}

/**
 * Helper function to load value from default value for checkboxes.
 */
function checkboxes_value(&$form) {
  $value = array();
  $form += array('#default_value' => array());
  foreach ($form['#default_value'] as $key) {
    $value[$key] = 1;
  }
  $form['#value'] = $value;
}

function password_confirm_value(&$form) {
  $form += array('#default_value' => array());
  $form['#value'] = $form['#default_value'] + array('pass1' => '', 'pass2' => '');
}

/**
 * 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])) {
        $element[$key] = array(
          '#type' => 'radio',
          '#title' => $choice,
          '#return_value' => $key,
          '#default_value' => isset($element['#default_value']) ? $element['#default_value'] : NULL,
          '#attributes' => $element['#attributes'],
          '#parents' => $element['#parents'],
        );
      }
    }
  }
  return $element;
}

/**
 * Format a form item.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used:  title, value, description, required, error
 * @return
 *   A themed HTML string representing the form item.
 */
function theme_item($element) {
  return theme('form_element', $element, $element['#value'] . (!empty($element['#children']) ? $element['#children'] : ''));
}

/**
 * Format a checkbox.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used:  title, value, return_value, description, required
 * @return
 *   A themed HTML string representing the checkbox.
 */
function theme_checkbox($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 $element
 *   An associative array containing the properties of the element.
 * @return
 *   A themed HTML string representing the checkbox set.
 */
function theme_checkboxes($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;
}

function theme_submit($element) {
  return theme('button', $element);
}

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";
}

/**
 * Format a hidden form field.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used:  value, edit
 * @return
 *   A themed HTML string representing the hidden form field.
 */
function theme_hidden($element) {
  return '<input type="hidden" name="'. $element['#name'] .'" id="'. $element['#id'] .'" value="'. check_plain($element['#value']) ."\" ". drupal_attributes($element['#attributes']) ." />\n";
}

function theme_token($element) {
  return theme('hidden', $element);
}

/**
 * Format a textfield.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used:  title, value, description, size, maxlength, required, attributes autocomplete_path
 * @return
 *   A themed HTML string representing the textfield.
 */
function theme_textfield($element) {
  $size = $element['#size'] ? ' size="'. $element['#size'] .'"' : '';
  $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="'. $element['#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 $element
 *   An associative array containing the properties of the element.
 *   Properties used: action, method, attributes, children
 * @return
 *   A themed HTML string representing the form.
 */
function theme_form($element) {
  // Anonymous div to satisfy XHTML compliance.
  $action = $element['#action'] ? 'action="'. check_url($element['#action']) .'" ' : '';
  return '<form '. $action .' method="'. $element['#method'] .'" id="'. $element['#id'] .'"'. drupal_attributes($element['#attributes']) .">\n<div>". $element['#children'] ."\n</div></form>\n";
}

/**
 * Format a textarea.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used: title, value, description, rows, cols, required, attributes
 * @return
 *   A themed HTML string representing the textarea.
 */
function theme_textarea($element) {
  $class = array('form-textarea');

  // Add teaser behaviour (must come before resizable)
  if (!empty($element['#teaser'])) {
    drupal_add_js('misc/teaser.js');
    // Note: arrays are merged in drupal_get_js().
    drupal_add_js(array('teaserButton' => array(t('Join summary'), t('Split summary at cursor'))), 'setting');
    drupal_add_js(array('teaserCheckbox' => array($element['#id'] => $element['#teaser_checkbox'])), 'setting');
    drupal_add_js(array('teaser' => array($element['#id'] => $element['#teaser'])), 'setting');
    $class[] = 'teaser';
  }

  // Add resizable behaviour
  if ($element['#resizable'] !== FALSE) {
    drupal_add_js('misc/textarea.js');
    $class[] = 'resizable';
  }

  $cols = $element['#cols'] ? ' cols="'. $element['#cols'] .'"' : '';
  _form_set_class($element, $class);
  return theme('form_element', $element, '<textarea'. $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.
 */

function theme_markup($element) {
  return (isset($element['#value']) ? $element['#value'] : '') . (isset($element['#children']) ? $element['#children'] : '');
}

/**
 * Format a password field.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used:  title, value, description, size, maxlength, required, attributes
 * @return
 *   A themed HTML string representing the form.
 */
function theme_password($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 $required
 *   Whether the user must upload a file to the field.
 * @return
 *   A themed HTML string representing the field.
 *
 * For assistance with handling the uploaded file correctly, see the API
 * provided by file.inc.
 */
function theme_file($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 $value
 *   The form element's data.
 * @return
 *   A string representing the form element.
 */
function theme_form_element($element, $value) {
  $output  = '<div class="form-item"';
  if (!empty($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' => $title, '!required' => $required)) ."</label>\n";
    }
    else {
      $output .= ' <label>'. t('!title: !required', array('!title' => $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);
}

/**
 * Remove invalid characters from an HTML ID attribute string.
 *
 * @param $id
 *   The ID to clean.
 * @return
 *   The cleaned ID.
 */
function form_clean_id($id = NULL) {
  $id = str_replace(array('][', '_', ' '), '-', $id);
  return $id;
}

/**
 * @} End of "defgroup form".
 */

/**
 * @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($batch);
 * // only needed if not inside a form _submit callback :
 * batch_process();
 * @endcode
 *
 * Sample batch operations:
 * @code
 * // Simple and artificial: load a node of a given type for a given user
 * function my_function_1($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 curent 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 means the operation is finished and processing can continue
 *   //   to the next operation. This value always be 1 if not specified
 *   //   by the batch operation (a single-step operation), so that will
 *   //   be considered as finished.
 *   $node = node_load(array('uid' => $uid, 'type' => $type));
 *   $context['results'][] = $node->nid .' : '. $node->title;
 *   $context['message'] = $node->title;
 * }
 *
 * // More advanced example: mutli-step operation - load all nodes, five by five
 * function my_function_2(&$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 node processed.', '@count nodes processed.');
 *   }
 *   else {
 *     $message = t('Finished with an error.');
 *   }
 *   drupal_set_message($message);
 *   // Provinding 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 $_SESSION for display after final page redirection.
 *
 * Operations are added as new batch sets. Batch sets are used to ensure
 * clean code independency, ensuring that several batches submitted by
 * different parts of the code (core / contrib modules) can be processed
 * correctly while not interfering or having to cope with each other. Each
 * batch set gets to specify his own UI messages, operates on it's own set
 * of operations and results, and triggers it's own 'finished' callback.
 * Batch sets are processed sequentially, with the progress bar starting
 * fresh for every new set.
 */
function batch_set($batch_definition) {
  if ($batch_definition) {
    $batch =& batch_get();
    // Initialize the batch
    if (empty($batch)) {
      $batch = array(
        'id' => db_next_id('{batch}_bid'),
        '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 callback),
    // 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 markes with 'progressive' = FALSE, the function
 * isses a drupal_goto and thus ends page execution.
 *
 * This function is not needed in form submit callbacks; Form API takes care
 * of batches issued during form submission.
 *
 * @param $redirect
 *   (optional) Path to redirect to when the batch has finished processing.
 * @param $url
 *   (optional - should ony be used for separate scripts like update.php)
 *   URL of the batch processing page.
 */
function batch_process($redirect = NULL, $url = NULL) {
  global $form_values, $user;
  $batch =& batch_get();

  // batch_process should not be called inside form _submit callbacks, or while a
  // batch is already running. Neutralize the call if it is the case.
  if (isset($batch['current_set']) || (isset($form_values) && !isset($batch['progressive']))) {
    return;
  }

  if (isset($batch)) {
    // Add process information
    $t = get_t();
    $url = isset($url) ? $url : 'batch';
    $process_info = array(
      'current_set' => 0,
      'progressive' => TRUE,
      'url' => isset($url) ? $url : 'batch',
      'source_page' => $_GET['q'],
      'redirect' => $redirect,
      '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' => 'error'))))),
    );
    $batch += $process_info;

    if ($batch['progressive']) {
      // Save and unset the destination if any. drupal_goto looks for redirection
      // in $_REQUEST['destination'] and $_REQUEST['edit']['destination'].
      if (isset($_REQUEST['destination'])) {
        $batch['destination'] = $_REQUEST['destination'];
        unset($_REQUEST['destination']);
      }
      elseif (isset($_REQUEST['edit']['destination'])) {
        $batch['destination'] = $_REQUEST['edit']['destination'];
        unset($_REQUEST['edit']['destination']);
      }
      db_query("INSERT INTO {batch} (bid, sid, timestamp, batch) VALUES (%d, %d, %d, '%s')", $batch['id'], $user->sid, time(), serialize($batch));
      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();
    }
  }
}

/**
 * Retrive the current batch.
 */
function &batch_get() {
  static $batch = array();
  return $batch;
}

/**
 * @} End of "defgroup batch".
 */