Http in Dart?

[Douglas Miller]

The api docs say there's an angular2/http library in JavaScript and TypeScript, but as far as I can tell it doesn't exist in the Dart version. Am I missing something? Is it not implemented yet? Something else?

The Dart api docs essentially say "see JavaScript docs" full stop, and I was under the impression that the use of code generation meant all three languages would have all exactly the same Angular features, so I'm a bit surprised and disappointed if this is missing. Searching through the Dart source that pub got for me, angular2/http does not exist and only one class (angular2/src/services/xhr_impl) does anything with http, and that class appears to be intended for internal use only.

[Günter Zöchbauer]

There is no Dart implementation for Http. You can just use what `dart:html` or `package:http` provide or create your own wrapper class if you want specific functionality. 

[Douglas Miller]

But does that work with Angular's dependency injection? I want to be able to mock it in tests.

...some quick googling says probably yes, I think. I'm new to Dart as well as Angular2, looks like I should have explored what Dart itself provides a bit more.

[Günter Zöchbauer]

I built this code just to get tests running I ported from TypeScript to Dart

import 'dart:async' show Future;
import 'dart:html' show HttpRequest;
import 'dart:convert' show JSON;

class Http {
  Future<Response> get(String uri) async {
    final HttpRequest req = new HttpRequest()..open('GET', uri);
    await req.onLoadEnd.first;
    req.send();
    return new Response(req);
  }
}

class Response {
  final HttpRequest request;
  Response(this.request);

  String text() => request.responseText;
  dynamic json() => JSON.decode(request.response);

} 

It has only a `get()` method, but other methods are quite similar.

You can get inspiration from the TypeScript source about what features to add.

For mocking, just extend it `class MockHttp extends Http {` and override the methods with dummy actions.

[Douglas Miller]

I just spent a few hours wrestling with it (the error messages I got weren't very meaningful), and it appears Angular 2's injector can't handle any class not annotated with @Injectable or another Angular-specific annotation. This means Dart's existing non-Angular classes for http handling cannot be injected, and thus cannot have mocks injected in their place. I can write injectable wrappers easily enough, but that's exactly the sort of boilerplate busywork that Angular is supposed to help avoid.

So, I guess I'll write injectable wrappers for now, but having angular2/http available in Dart would be much preferred. I suppose injection of non-annotated classes that have a suitable constructor might also work, but HttpRequest in dart:html seems to be intended for a single request and BrowserClient in package:http says it can't do streaming. What would be the best way to try to get this handled long term, submit an issue report on github?

[Günter Zöchbauer]

AFAIR there was an issue and they declined to implement it. They don't want to maintain all kinds of features usually requested around HTTP as part of Angular and I understand.
AFAIR I used streaming with the http package. I don't remember where. If I find the code I can post it. It wasn't difficult, only a bit difficult to find.

[Günter Zöchbauer]

Here is the code for http with streaming response

https://github.com/bwu-dart/bwu_docker/blob/0244aa90079e4e8515b5ca412e73b8f858cab809/lib/src/remote_api.dart#L152