how to write a simple http intercept? - dart

Question

Can somebody explain what is wrong with the following?
void main() {
var intercept = new HttpInterceptor();
intercept.response = (HttpResponse response) => print('we have a response');
Injector injector = ngBootstrap(module: new MyModule());
var interceptors = injector.get(HttpInterceptors);
interceptors.add(intercept);
}
Thanks in advance
EDIT:
And here is how I do an http request (from inside a directive):
#NgDirective(
selector: '.my-selector')
class MyDirective implements NgAttachAware {
#NgOneWay('id')
String id;
Element self;
MyDirective(Element el) {
self = el;
}
void attach() {
final String _urlBase = 'http://www.some-site.com/';
HttpRequest req = new HttpRequest();
req.open('GET', _urlBase + id);
req.overrideMimeType('text\/plain; charset=x-user-defined');
req.onLoadEnd.listen((e) {
if (req.status == 200) {
// do something useful
} else {
print('download failed');
}
});
req.send();
}
}
Requests return successfully but the interceptor never fires. Why?

Answer 1

You must use the AngularDart built-in service "Http" and not the dart:html HttpRequest class.
The HttpInterceptors only work on when using that service which wraps the HttpRequest class.
In other words, inject Http in the directive´s constructor:
MyDirective(Element el, Http http) {
self = el;
this._http = http;
}