I'm trying to connect a websocket in Dart:
@Injectable()
class Sock {
...
Future<WebSocket> connect() async {
return WebSocket.connect("ws://....");
}
}
As soon as I call connect()
, I'm seeing an error which seems unrelated:
EXCEPTION: 'dart:io-patch/platform_patch.dart': error: line 25: native function 'Platform_GetVersion' (0 arguments) cannot be found
static String _version() native "Platform_GetVersion";
^
STACKTRACE:
platform_impl.dart 110 _Platform.version
platform.dart 73 Platform._version
platform.dart 73 Platform._version
platform.dart 229 Platform.version
http_impl.dart 2843 _getHttpVersion
http_impl.dart 1672 new _HttpClient
http.dart 1338 new HttpClient
websocket_impl.dart 968 _WebSocketImpl._httpClient
websocket_impl.dart 968 _WebSocketImpl._httpClient
websocket_impl.dart 994 _WebSocketImpl.connect
websocket.dart 319 WebSocket.connect
package:atomcomponents/util/sock.dart 44:20 Sock.connect
package:atomcomponents/util/sock.dart 35:21 new Sock.<fn>
dart:async _ZoneDelegate.runUnary
package:angular2/src/core/zone/ng_zone.dart 184:21 NgZone._runUnary
dart:async _ZoneDelegate.runUnary
package:angular2/src/core/zone/ng_zone.dart 184:21 NgZone._runUnary
VM276:1 EXCEPTION: NoSuchMethodError: The method 'openUrl' was called on null.
Receiver: null
Tried calling: openUrl("GET", Instance of '_Uri')
STACKTRACE:
dart:core Object.noSuchMethod
websocket_impl.dart 994 _WebSocketImpl.connect
websocket.dart 319 WebSocket.connect
package:atomcomponents/util/sock.dart 44:20 Sock.connect
package:atomcomponents/util/sock.dart 32:21 new Sock.<fn>
dart:async _ZoneDelegate.runUnary
package:angular2/src/core/zone/ng_zone.dart 184:21 NgZone._runUnary
dart:async _ZoneDelegate.runUnary
package:angular2/src/core/zone/ng_zone.dart 184:21 NgZone._runUnary
Somebody suggested that I add BrowserClient to bootstrap
// bootstrap angular2
bootstrap(AppComponent, [
ROUTER_PROVIDERS,
provide(APP_BASE_HREF, useValue: '/'),
provide(LocationStrategy, useClass: HashLocationStrategy),
provide(BrowserClient, useFactory: () => new BrowserClient(), deps: [])
]);
This is however not making any difference, WebSocket.connect
is still failing with the same enormous stacktrace.
In older code, new WebSocket("ws://...");
used to work, but WebSocket
is now an abstract class and that constructor has been deprecated.
@Deprecated('This constructor will be removed in Dart 2.0. Use `implements`'
' instead of `extends` if implementing this abstract class.')
WebSocket();
The documentation literally only mentions it: https://webdev.dartlang.org/angular/guide/server-communication
The WebSocket protocol is another important communication technology; it isn’t covered in this page.
I'm on Angular 3.1.0
and Dart 1.24.2
Can WebSockets be used with Angular and if so, what is missing to make it work?
Mmmm, seems I was using the backend implementation of Sockets for some reason, changed my import from dart:io
and it's working now.
import 'dart:html';
And this connects:
new WebSocket("ws://...");