title: angulardart firestore throw error "firebase.firestore is not a function"
body: <p>Sorry, newbie question here. Here is my firebase_service.dart</p>
  
  <pre><code>import 'package:firebase/firebase.dart' as fb;
  import 'package:firebase/firestore.dart' as fs;
  import 'dart:async';
  import 'package:angular/angular.dart';
  
  @Injectable()
  class FirebaseService {
    fb.User user;
    fs.DocumentReference reference;
  
    FirebaseService() {
      fb.initializeApp(
          apiKey: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
          authDomain: "xxxxxx.firebaseapp.com",
          databaseURL: "https://xxxxxx.firebaseio.com",
          projectId: "xxxxxxx",
          storageBucket: "xxxxxxxxxxxx.appspot.com",
          messagingSenderId: "xxxxxxxxxx"
      );
  
      fb.auth().onAuthStateChanged.listen(_authChanged);
    }
  
      void _authChanged(fb.User event) =&gt; user = event;
  
    Future signIn() async {
      try {
        await fb.auth().signInWithPopup(new fb.GoogleAuthProvider());
      }
      catch (e) {
        print("$runtimeType::login() -- $e");
      }
    }
  
    void signOut() =&gt; fb.auth().signOut();
  
    Future submitName(id, name) async {
      reference = fb.firestore().doc('userdata/$id');
      try {
          await reference.set(id(name));
        } catch (e) {
          print('error submitting: $e');
        }
    }
  }
  </code></pre>
  
  <p>I am trying to submit user name and user id to firestore by calling</p>
  
  <pre><code>fbService.submitName(id, name);
  </code></pre>
  
  <p>but I got this error</p>
  
  <pre><code>error submitting: NoSuchMethodError: method not found: 'call$1' (id.call$1 is not a function)
  </code></pre>
  
  <p>I don't know whats wrong with my code. I have tried looking for some angulardart firestore tutorial but got no luck. I am using dart-sdk 1.24.3, angular 4.0.0+2 and firebase 4.4.0</p>
  
  <p>I have tried using this based on <a href="https://pub.dartlang.org/packages/firebase" rel="nofollow noreferrer">pub website</a></p>
  
  <pre><code>&lt;script src="https://www.gstatic.com/firebasejs/4.10.1/firebase.js"&gt;&lt;/script&gt;
  &lt;script src="https://www.gstatic.com/firebasejs/4.10.1/firebase-firestore.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>and this</p>
  
  <pre><code>&lt;script src="https://www.gstatic.com/firebasejs/4.11.0/firebase.js"&gt;&lt;/script&gt;
  &lt;script src="https://www.gstatic.com/firebasejs/4.11.0/firebase-firestore.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>but still got the same error</p>