1 ajax.inc | ajax_deliver($page_callback_result) |
Packages and sends the result of a page callback as an Ajax response.
This function is the equivalent of backdrop_deliver_html_page(), but for Ajax requests. Like that function, it:
- Adds needed HTTP headers.
- Prints rendered output.
- Performs end-of-request tasks.
Parameters
$page_callback_result: The result of a page callback. Can be one of:
- NULL: to indicate no content.
- An integer menu status constant: to indicate an error condition.
- A string of HTML content.
- A renderable array of content.
See also
Related topics
File
- core/
includes/ ajax.inc, line 477 - Functions for use with Backdrop's Ajax framework.
Code
function ajax_deliver($page_callback_result) {
// Browsers do not allow JavaScript to read the contents of a user's local
// files. To work around that, the jQuery Form plugin submits forms containing
// a file input element to an IFRAME, instead of using XHR. Browsers do not
// normally expect JSON strings as content within an IFRAME, so the response
// must be customized accordingly.
// @see http://malsup.com/jquery/form/#file-upload
// @see Backdrop.ajax.prototype.beforeSend()
$iframe_upload = !empty($_POST['ajax_iframe_upload']);
// Emit a Content-Type HTTP header if none has been added by the page callback
// or by a wrapping delivery callback.
if (is_null(backdrop_get_http_header('Content-Type'))) {
if (!$iframe_upload) {
// Standard JSON can be returned to a browser's XHR object, and to
// non-browser user agents.
// @see http://www.ietf.org/rfc/rfc4627.txt?number=4627
backdrop_add_http_header('Content-Type', 'application/json; charset=utf-8');
}
else {
// Browser IFRAMEs expect HTML. With most other content types, Internet
// Explorer presents the user with a download prompt.
backdrop_add_http_header('Content-Type', 'text/html; charset=utf-8');
}
}
// Let ajax.js know that this response is safe to process.
ajax_set_verification_header();
// Print the response.
$commands = ajax_prepare_response($page_callback_result);
$json = ajax_render($commands);
if (!$iframe_upload) {
// Standard JSON can be returned to a browser's XHR object, and to
// non-browser user agents.
print $json;
}
else {
// Browser IFRAMEs expect HTML. Browser extensions, such as Linkification
// and Skype's Browser Highlighter, convert URLs, phone numbers, etc. into
// links. This corrupts the JSON response. Protect the integrity of the
// JSON data by making it the value of a textarea.
// @see http://malsup.com/jquery/form/#file-upload
// @see http://drupal.org/node/1009382
print '<textarea>' . $json . '</textarea>';
}
// Perform end-of-request tasks.
ajax_footer();
}