In iOS 7, Apple introduced the possibility to [execute JavaScript via the JavaScriptCore JavaScript
engine] (http://nshipster.com/javascriptcore/). Unfortunately, JavaScriptCore is missing some
objects and functions a JavaScript environment of a browser would have. Especially the
XMLHttpRequest
(see the [Mozilla documentation]
(https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest) object needed for AJAX requests
is not provided by JavaScriptCore. This library implements this missing object, so it is possible to
use JavaScript libraries which were originally developed for in-browser use in your Objective-C
(or Swift) application without the need to use a hidden WebView.
This library tries to implement the full XMLHttpRequest specification. Currently not all functionality is implemented yet. The current limitations are:
- Synchronous calls are not supported.
- The
onload
andonerror
callbacks are currently not supported. - The
upload
callback is currently not supported. - The
timeout
property is currently not supported.
It is planned to support all functionality of the HTML5 specification at some point.
Create a new instance of the XMLHTTPRequest
class. Then call the extend:
method and pass either
a JSContext
instance or a JSValue
instance. The given object will be extend with the
XMLHTTPRequest
object.
#import <XMLHTTPRequest/XMLHTTPRequest.h>
...
JSContext *jsContext = [JSContext new];
XMLHttpRequest *xmlHttpRequest = [XMLHttpRequest new];
[xmlHttpRequest extend:jsContext];
The JavaScript context now has a XMLHTTPRequest object you can use like the object found in browsers. Example (JavaScript):
request.open('GET', 'http://example.com');
request.setRequestHeader('Accept', 'text/html');
request.setRequestHeader('X-Foo', 'bar');
request.send();
If you are interested in more polyfills for missing browser functionality in JavaScriptCore, there is
a window timers implementation (setTimeout
, setInterval
, ...) called [WindowTimers]
(https://github.com/Lukas-Stuehrk/WindowTimers).