How can I ensure that a user variable stored in an Angular6 service remains defined and accessible from other components?

Question

How can I ensure that a user variable stored in an Angular6 service remains defined and accessible from other components?

Currently, I am working on an Angular app and facing a challenge. After receiving a user variable from an asynchronous call to Firestore Cloud, I noticed that the variable is successfully set (verified using console.log()). However, when I navigate between pages and attempt to load the recipes associated with that user on Firestore, it indicates that the user variable is undefined.

Is there a more effective approach to handle this situation?

Thank you

EDIT: Code

tryConnect(email: string, password: string) {
// u = array of users
this.usersWithId.subscribe(u => {
  for (const a of u) {
    console.log(a);
    if (a.email === email && a.password === password) {
      this.connectedUser = a;
      console.log(this.connectedUser);
      break;
    }
  }
});

}

addRecipe(recipe: Recipe) {
console.log(this.connectedUser);
this.db.collection('/recipes').add({
  name: recipe.name,
  description: recipe.description,
  meal: recipe.meal,
  steps: recipe.steps,
  servings: recipe.servings,
  cuisine: recipe.cuisine,
  userID: this.connectedUser.userID,
  ingredients: recipe.ingredients
});

angular typescript google-cloud-firestore angular6 webstorm

Answer 1

Answer №1

If you're looking to accomplish a task, consider utilizing a state management system like rxjs/store. This allows you to store data throughout your application and have it synchronized wherever it's accessed.

Another alternative is using sessionStorage or localStorage for saving data across different sessions.

Answer 2

If you're looking to accomplish a task, consider utilizing a state management system like rxjs/store. This allows you to store data throughout your application and have it synchronized wherever it's accessed.

Another alternative is using sessionStorage or localStorage for saving data across different sessions.

Answer 3

Answer №2

If you're not already utilizing it, my recommendation would be to incorporate @angular/fire.

Here's a method to make use of @angular/fire for your intended purpose.

Once injected as a dependency, AngularFireAuth provides an authState property that holds an Observable<firebase.User>. This represents the current login status of the user.

In your service, you can establish a private

BehaviorSubject<Observable<firebase.User>>

, where the next function will trigger upon any change in authState.

You can then expose this

BehaviourSubject<firebase.User>

using asObservable. By doing so, any component that utilizes your service as a dependency will have access to the user$ Observable to subscribe and obtain the current user's status.

Below is how you can implement this functionality in code:

import { AngularFireAuth } from '@angular/fire/auth';
import { Injectable } from '@angular/core';
import { Observable, BehaviorSubject } from 'rxjs';
import { switchMap } from 'rxjs/operators;

import { User } from '@app/shared/models/user.model';

@Injectable()
export class AuthService {

  private user: BehaviorSubject<Observable<firebase.User>> = new BehaviorSubject<Observable<firebase.User>>(null);
  user$ = this.user.asObservable().pipe(switchMap(user => user));

  constructor(
    private afAuth: AngularFireAuth
  ) {
    this.user.next(this.afAuth.authState);
  }

  loginViaCredentails(user: User) {
    return this.afAuth.auth.signInWithEmailAndPassword(user.email, user.password);
  }

  ...

}

Answer 4

If you're not already utilizing it, my recommendation would be to incorporate @angular/fire.

Here's a method to make use of @angular/fire for your intended purpose.

Once injected as a dependency, AngularFireAuth provides an authState property that holds an Observable<firebase.User>. This represents the current login status of the user.

In your service, you can establish a private

BehaviorSubject<Observable<firebase.User>>

, where the next function will trigger upon any change in authState.

You can then expose this

BehaviourSubject<firebase.User>

using asObservable. By doing so, any component that utilizes your service as a dependency will have access to the user$ Observable to subscribe and obtain the current user's status.

Below is how you can implement this functionality in code:

import { AngularFireAuth } from '@angular/fire/auth';
import { Injectable } from '@angular/core';
import { Observable, BehaviorSubject } from 'rxjs';
import { switchMap } from 'rxjs/operators;

import { User } from '@app/shared/models/user.model';

@Injectable()
export class AuthService {

  private user: BehaviorSubject<Observable<firebase.User>> = new BehaviorSubject<Observable<firebase.User>>(null);
  user$ = this.user.asObservable().pipe(switchMap(user => user));

  constructor(
    private afAuth: AngularFireAuth
  ) {
    this.user.next(this.afAuth.authState);
  }

  loginViaCredentails(user: User) {
    return this.afAuth.auth.signInWithEmailAndPassword(user.email, user.password);
  }

  ...

}

How can I ensure that a user variable stored in an Angular6 service remains defined and accessible from other components?

Answer №1

Answer №2

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