function ajax_render

Renders a commands array into JSON.

Parameters

$commands: A list of macro commands generated by the use of ajax_command_*() functions.

Related topics

File

includes/ajax.inc, line 232

Code

function ajax_render($commands = array()) {
    // Although ajax_deliver() does this, some contributed and custom modules
    // render Ajax responses without using that delivery callback.
    ajax_set_verification_header();
    // Ajax responses aren't rendered with html.tpl.php, so we have to call
    // drupal_get_css() and drupal_get_js() here, in order to have new files added
    // during this request to be loaded by the page. We only want to send back
    // files that the page hasn't already loaded, so we implement simple diffing
    // logic using array_diff_key().
    foreach (array(
        'css',
        'js',
    ) as $type) {
        // It is highly suspicious if $_POST['ajax_page_state'][$type] is empty,
        // since the base page ought to have at least one JS file and one CSS file
        // loaded. It probably indicates an error, and rather than making the page
        // reload all of the files, instead we return no new files.
        if (empty($_POST['ajax_page_state'][$type])) {
            $items[$type] = array();
        }
        else {
            $function = 'drupal_add_' . $type;
            $items[$type] = $function();
            drupal_alter($type, $items[$type]);
            // @todo Inline CSS and JS items are indexed numerically. These can't be
            //   reliably diffed with array_diff_key(), since the number can change
            //   due to factors unrelated to the inline content, so for now, we strip
            //   the inline items from Ajax responses, and can add support for them
            //   when drupal_add_css() and drupal_add_js() are changed to use a hash
            //   of the inline content as the array key.
            foreach ($items[$type] as $key => $item) {
                if (is_numeric($key)) {
                    unset($items[$type][$key]);
                }
            }
            // Ensure that the page doesn't reload what it already has.
            $items[$type] = array_diff_key($items[$type], $_POST['ajax_page_state'][$type]);
        }
    }
    // Render the HTML to load these files, and add AJAX commands to insert this
    // HTML in the page. We pass TRUE as the $skip_alter argument to prevent the
    // data from being altered again, as we already altered it above. Settings are
    // handled separately, afterwards.
    if (isset($items['js']['settings'])) {
        unset($items['js']['settings']);
    }
    $styles = drupal_get_css($items['css'], TRUE);
    $scripts_footer = drupal_get_js('footer', $items['js'], TRUE);
    $scripts_header = drupal_get_js('header', $items['js'], TRUE);
    $extra_commands = array();
    if (!empty($styles)) {
        $extra_commands[] = ajax_command_add_css($styles);
    }
    if (!empty($scripts_header)) {
        $extra_commands[] = ajax_command_prepend('head', $scripts_header);
    }
    if (!empty($scripts_footer)) {
        $extra_commands[] = ajax_command_append('body', $scripts_footer);
    }
    if (!empty($extra_commands)) {
        $commands = array_merge($extra_commands, $commands);
    }
    // Now add a command to merge changes and additions to Drupal.settings.
    $scripts = drupal_add_js();
    drupal_alter('js', $scripts);
    if (!empty($scripts['settings'])) {
        $settings = $scripts['settings'];
        array_unshift($commands, ajax_command_settings(drupal_array_merge_deep_array($settings['data']), TRUE));
    }
    // Allow modules to alter any Ajax response.
    drupal_alter('ajax_render', $commands);
    return drupal_json_encode($commands);
}