Angular 4 Firebase Read data from database and display to browser

问题

I am learning Angular 4 and I am using firebase database.But I am completly lost on how I can make the objects apear on the browser of my application. I currently want to take all the data from users and display them on the browser.

import { Component, OnInit } from '@angular/core';
import { AngularFireDatabase, FirebaseListObservable } from 'angularfire2/database';
import * as firebase from 'firebase/app';

@Component({
  selector: 'app-about',
  templateUrl: './about.component.html',
  styleUrls: ['./about.component.css']
})
export class AboutComponent implements OnInit {

  constructor() {
    var allUsers = firebase.database().ref('users/');
      var db = firebase.database().ref('/users/');
      // Attach an asynchronous callback to read the data at our posts reference
        db.on("value", function(snapshot) {
          console.log(snapshot.val());
        }, function (errorObject) {
          console.log("The read failed: " + errorObject.code);
        });
          }

  ngOnInit() {
  }

}

Everything works fine and I can see my data on the console.But can you help me on how I can make the data on the console apear on the browser??

回答1:

Well there is no need to use console.log() if you want to display data on Browser.Angularfire has its own functions for this. This link focus exactly on your problem

Here is an example that takes all the users name from a database and displays them as a list

import { Component, OnInit } from '@angular/core';
import { AngularFireDatabase, FirebaseListObservable,FirebaseObjectObservable } from 'angularfire2/database';
import * as firebase from 'firebase/app';

@Component({
  selector: 'app-about',
  templateUrl: './about.component.html',
  styleUrls: ['./about.component.css']
})
export class AboutComponent implements OnInit {

    users:FirebaseListObservable<any>;;
    constructor(db2: AngularFireDatabase) {
    this.users = db2.list('users');
          }
  ngOnInit() {
  }

And the following Html code

<div class="container">
  <p>Show all users</p>
  <ul>
  <li *ngFor="let user of users | async">
       {{ user.name | json }}
    </li>
  </ul>
</div>

Hope it reduced your confusion on the matter.If you didnt understant something plz ask me again

来源：https://stackoverflow.com/questions/45242925/angular-4-firebase-read-data-from-database-and-display-to-browser