function ajax_form_callback in Drupal 7
Menu callback; handles Ajax requests for the #ajax Form API property.
This rebuilds the form from cache and invokes the defined #ajax['callback'] to return an Ajax command structure for JavaScript. In case no 'callback' has been defined, nothing will happen.
The Form API #ajax property can be set both for buttons and other input elements.
This function is also the canonical example of how to implement #ajax['path']. If processing is required that cannot be accomplished with a callback, re-implement this function and set #ajax['path'] to the enhanced function.
See also
Related topics
1 string reference to 'ajax_form_callback'
- system_menu in modules/
system/ system.module - Implements hook_menu().
File
- includes/
ajax.inc, line 385 - Functions for use with Drupal's Ajax framework.
Code
function ajax_form_callback() {
list($form, $form_state, $form_id, $form_build_id, $commands) = ajax_get_form();
drupal_process_form($form['#form_id'], $form, $form_state);
// We need to return the part of the form (or some other content) that needs
// to be re-rendered so the browser can update the page with changed content.
// Since this is the generic menu callback used by many Ajax elements, it is
// up to the #ajax['callback'] function of the element (may or may not be a
// button) that triggered the Ajax request to determine what needs to be
// rendered.
if (!empty($form_state['triggering_element'])) {
$callback = $form_state['triggering_element']['#ajax']['callback'];
}
if (!empty($callback) && is_callable($callback)) {
$result = $callback($form, $form_state);
if (!(is_array($result) && isset($result['#type']) && $result['#type'] == 'ajax')) {
// Turn the response into a #type=ajax array if it isn't one already.
$result = array(
'#type' => 'ajax',
'#commands' => ajax_prepare_response($result),
);
}
$result['#commands'] = array_merge($commands, $result['#commands']);
return $result;
}
}