title: ngFor not working, Firestore
body: <p>I am attempting an example of using Angular5 with Firestore, but I cannot retrieve any data from my Firestore database. Any help would be greatly appreciated as this is a show stopper. The irony is I can insert new records into the database using the example, I just cannot retrieve anything. Thanks in advance.</p>
  
  <p>app.component.html:</p>
  
  <pre><code>&lt;ul *ngFor="let post of posts | async"&gt;
    &lt;li&gt;
      &lt;strong&gt;{{ post.title }}&lt;/strong&gt;
      &lt;br&gt;
      {{ post.content }}
    &lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>app.component.ts:</p>
  
  <pre><code>import { Component } from '@angular/core';
  
  import { AngularFirestore } from 'angularfire2/firestore';
  import { AngularFirestoreCollection } from 'angularfire2/firestore';
  import { AngularFirestoreDocument } from 'angularfire2/firestore';
  
  import { Observable } from 'rxjs/Observable';
  import 'rxjs/add/operator/map';
  
  interface Post {
    title: string;
    content: string;
  }
  
  @Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
  })
  export class AppComponent {
  
    postsCollection: AngularFirestoreCollection&lt;Post&gt;;
    posts: Observable&lt;Post[]&gt;;
  
    constructor (private afs: AngularFirestore) {
  
    }
  
    ngOnit() {
      this.postsCollection = this.afs.collection('posts');
      this.posts = this.postsCollection.valueChanges();
    }
  }
  </code></pre>
  
  <p>app.module.ts</p>
  
  <pre><code>import { BrowserModule } from '@angular/platform-browser';
  import { NgModule } from '@angular/core';
  
  import { AppComponent } from './app.component';
  
  import { AngularFireModule } from 'angularfire2';
  import { AngularFirestoreModule } from 'angularfire2/firestore';
  
  import { FormsModule } from '@angular/forms';
  
  var firebaseConfig = {
    apiKey: "edited but correct",
    authDomain: "edited but correct",
    databaseURL: "edited but correct",
    projectId: "edited but correct",
    storageBucket: "",
    messagingSenderId: "edited but correct"
  };
  
  @NgModule({
    declarations: [
      AppComponent
    ],
    imports: [
      BrowserModule,
      AngularFireModule.initializeApp(firebaseConfig),
      AngularFirestoreModule,
      FormsModule
    ],
    providers: [],
    bootstrap: [AppComponent]
  })
  export class AppModule { }
  </code></pre>