7.x ajax.inc ajax_prepare_response($page_callback_result)

Converts the return value of a page callback into an Ajax commands array.


$page_callback_result: The result of a page callback. Can be one of:

  • NULL: to indicate no content.
  • An integer menu status constant: to indicate an error condition.
  • A string of HTML content.
  • A renderable array of content.

Return value

An Ajax commands array that can be passed to ajax_render().

Related topics

2 calls to ajax_prepare_response()
ajax_deliver in includes/ajax.inc
Packages and sends the result of a page callback as an Ajax response.
ajax_form_callback in includes/ajax.inc
Menu callback; handles Ajax requests for the #ajax Form API property.


includes/ajax.inc, line 532
Functions for use with Drupal's Ajax framework.


function ajax_prepare_response($page_callback_result) {
  $commands = array();
  if (!isset($page_callback_result)) {

    // Simply delivering an empty commands array is sufficient. This results
    // in the Ajax request being completed, but nothing being done to the page.
  elseif (is_int($page_callback_result)) {
    switch ($page_callback_result) {
      case MENU_NOT_FOUND:
        $commands[] = ajax_command_alert(t('The requested page could not be found.'));
        $commands[] = ajax_command_alert(t('You are not authorized to access this page.'));
        $commands[] = ajax_command_alert(filter_xss_admin(variable_get('maintenance_mode_message', t('@site is currently under maintenance. We should be back shortly. Thank you for your patience.', array(
          '@site' => variable_get('site_name', 'Drupal'),
  elseif (is_array($page_callback_result) && isset($page_callback_result['#type']) && $page_callback_result['#type'] == 'ajax') {

    // Complex Ajax callbacks can return a result that contains an error message
    // or a specific set of commands to send to the browser.
    $page_callback_result += element_info('ajax');
    $error = $page_callback_result['#error'];
    if (isset($error) && $error !== FALSE) {
      if (empty($error) || $error === TRUE) {
        $error = t('An error occurred while handling the request: The server received invalid input.');
      $commands[] = ajax_command_alert($error);
    else {
      $commands = $page_callback_result['#commands'];
  else {

    // Like normal page callbacks, simple Ajax callbacks can return HTML
    // content, as a string or render array. This HTML is inserted in some
    // relationship to #ajax['wrapper'], as determined by which jQuery DOM
    // manipulation method is used. The method used is specified by
    // #ajax['method']. The default method is 'replaceWith', which completely
    // replaces the old wrapper element and its content with the new HTML.
    $html = is_string($page_callback_result) ? $page_callback_result : drupal_render($page_callback_result);
    $commands[] = ajax_command_insert(NULL, $html);

    // Add the status messages inside the new content's wrapper element, so that
    // on subsequent Ajax requests, it is treated as old content.
    $commands[] = ajax_command_prepend(NULL, theme('status_messages'));
  return $commands;


teknic’s picture

I'm trying to alter the location of the status messages. Instead of having them pushed into the top of the form, the desire is to have them inside the field grouped, vertical tabbed, node form that exists.

Any way to achieve this?