What are async route guards in Angular?

Can you explain what async route guards are in Angular?

Async route guards in Angular are used to control access to routes based on asynchronous conditions, like fetching data.

How do I implement an async route guard?

You can implement an async route guard by creating a service that implements the CanActivate interface and returns an Observable or Promise.

Can you give me a code example?

Sure! Here's a simple example:

import { Injectable } from '@angular/core';
import { CanActivate } from '@angular/router';
import { Observable } from 'rxjs';

@Injectable({ providedIn: 'root' })
export class AuthGuard implements CanActivate {
  canActivate(): Observable<boolean> {
    return this.authService.isLoggedIn(); // returns an Observable
  }
}

What happens if the async guard returns false?

If the async guard returns false, the navigation to the route is canceled, and the user remains on the current route.