function ajax_prepare_response

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

Parameters

$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

File

includes/ajax.inc, line 533

Code

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.'));
                break;
            case MENU_ACCESS_DENIED:
                $commands[] = ajax_command_alert(t('You are not authorized to access this page.'));
                break;
            case MENU_SITE_OFFLINE:
                $commands[] = ajax_command_alert(filter_xss_admin(variable_get('maintenance_mode_message', t('@site is currently under maintenance. We should be back shortly. Thank you for your patience.', array(
                    '@site' => variable_get('site_name', 'Drupal'),
                )))));
                break;
        }
    }
    elseif (is_array($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;
}