无法从提供商处获取 firebase 用户信息

Question

当我尝试在提供者的帮助下获取数据时遇到了问题。一切看起来都很好，但我还是做不到。

//Provider
import { Injectable } from '@angular/core';
import { AngularFireAuth } from 'angularfire2/auth';

@Injectable()
export class SomeProvider {
user: Observable<firebase.User>;

  constructor(private firebaseAuth: AngularFireAuth) {
    this.user = firebaseAuth.authState;
  }

this.firebaseAuth.authState.subscribe(user => {console.log(user.uid)}); // i can get UID with this
........

但是当我在这里调用它时，它返回未定义：

//menu.ts
import { SomeProvider } from '../../providers/some/some';
import { Component } from '@angular/core';
import { AngularFireAuth } from 'angularfire2/auth';

@IonicPage()
@Component({
  selector: 'page-menu',
  templateUrl: 'menu.html',
})
export class MenuPage {

constructor(private cfg: SomeProvider, private firebaseAuth: AngularFireAuth){}
ionViewDidLoad(){ 
console.log(this.cfg.user.uid);  //returns undefined
.....

我尝试过 firebase SDK，但遇到了同样的问题。

Answer 1

您缺少user: Observable<firebase.User>; 所需的firebase 导入，如果您还没有，您应该在SomeProvider 中导入它：

import * as firebase from 'firebase/app';

另外，根据您的代码，user 是一个 Observable，因此您需要订阅它：

export class MenuPage {

  constructor(private cfg: SomeProvider, private firebaseAuth: AngularFireAuth){}
  ionViewDidLoad(){ 
    this.cfg.user.subscribe(user => console.log(user.uid));

---

或者：

@Injectable()
export class SomeProvider {
  user: Observable<firebase.User>;
  userId: string; // initialize

  constructor(private firebaseAuth: AngularFireAuth) {
    this.user = firebaseAuth.authState;
    this.user.subscribe(user => this.userId = user.uid); // assign userId here
  }

  get getUserId(): string {
    return this.userId;
  }

然后在组件中：

export class MenuPage {

  constructor(private cfg: SomeProvider, private firebaseAuth: AngularFireAuth){}
  ionViewDidLoad(){ 
    console.log(this.cfg.getUserId); // user id should be logged here