I am trying to fetch my user's username from Firebase Firestore Database using Ionic and AngularFire. I am using the valueChanges()
method to get the observable, then trying to interpret the observable with an async pipe. However, when I run the code, I get the following error:
However, when I log the observable, it appears as shown:
profile.page.ts:
import { Component, OnInit } from '@angular/core';
import { AngularFireAuth } from '@angular/fire/auth';
import { Router } from '@angular/router';
import { UserService } from '../user.service'
import { AngularFirestore, AngularFirestoreCollection } from '@angular/fire/firestore'
import { Observable } from 'rxjs';
@Component({
selector: 'app-profile',
templateUrl: './profile.page.html',
styleUrls: ['./profile.page.scss'],
})
export class ProfilePage implements OnInit {
constructor(public afAuth: AngularFireAuth, public router: Router, public user: UserService, public db: AngularFirestore) {
}
ngOnInit() {
}
logout() { this.afAuth.auth.signOut(); this.router.navigate(['/login']);}
}
profile.page.html:
<ion-content>
<ion-grid>
<ion-row justify-content-center align-items-center style="height: 50%">
<ion-button color="danger" size="small" shape="round" (click)="logout()">Logout</ion-button>
<p *ngFor="let users of (username | async)">{{ users.username }}</p>
</ion-row>
</ion-grid>
</ion-content>
Thanks in advance for any help.
You have that error because your username data is not an array so I would suggest you change your code like this. Make your username become an array then push it into array
username: string[] = [];
this.username = this.username.push(users.valueChanges());
Hi are you sure that users
is an array?
Maybe a simple console.log(users) can give a better look of the data type you are receiving.
You should try to push/unshift to an array the mapped results from your service with a for of and return the array something like this for example:
private itemsCollection: AngularFirestoreCollection<User>
this.itemsCollection = this.afs.collection<User>('user', ref => ref.orderBy('name','desc').limit(5));
return this.itemsCollection.valueChanges().pipe(map( (users: User[]) =>{
let users = [];
for (const user of users) {
this.users.unshift(user);
}
return users
}))
afs is type AngularFirestore
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