In this article, I will discuss how to redirect one
page to other page and also discuss how to use the AuthGuard and CanActivate in
Angular 5 applications.
Three options are available to redirect page in
Angular 5 –
1. Imperatively
redirect the user in AppComponent
2. Use
the route data property
3. Use
a CanActivate guard
The AuthGuard should call an application service
that can login a user and retain information about the current user.
Options 1 – Imperatively redirect
the user in AppComponent
@Component({
selector: 'app-root',
template: `.....`
})
export class AppComponent {
constructor(private _authService: AuthService, _router: Router) {
if (_authService.isLoggedIn()) {
_router.navigate(['user']);
}
}
}
This is not good practice and I will not recommend
using this options.
Options 2 - Use the route data
property
This is the best solution and used by many expert
programmers. You can simply add some metadata in the routes declaration to indicate
that - “this route requires that the user must be loggedIn”.
const
APPROUTES: Routes
= [
{path: 'dashboard',
component: AppComponent,
data:{requiresLogin:
true}},
{path: 'user',
component: UserComponent,
data:{requiresLogin:
true}}
];
This is the best approach to redirect if not
logged in and I will recommend to this option.
Options 3 -Use a CanActivate guard
Firstly add a CanActivate guard to all the routes
that require the user to be logged in and my guard is called AuthGuard and see the following example
–
@NgModule({
declarations: [
AppComponent,
LoginComponent,
UserComponent
],
imports: [
BrowserModule,
FormsModule,
HttpClientModule,
RouterModule.forRoot([
{ path: '',
component: AppComponent,
pathMatch: 'full',
canActivate: [AuthGuard]},
{ path: 'user',
component: UserComponent,
canActivate: [AuthGuard]},
{ path: 'login',
component: LoginComponent}])
],
providers: [EmployeeService,
ValidationService,
AuthenticationService,
UserService],
bootstrap: [AppComponent]
})
export
class AppModule
{ }
And
import
{ Injectable } from
'@angular/core';
import
{ CanActivate, ActivatedRouteSnapshot,
RouterStateSnapshot
} from '@angular/router';
import
{ Observable } from
'rxjs/Observable';
import
{Router} from
'@angular/router';
import
{ AuthServiceService
} from './auth-service.service';
@Injectable()
export
class AuthGuard
implements CanActivate
{
//constructor initialization
constructor(private
authService: AuthServiceService, private
route: Router){ }
//can Activate Route
canActivate(
next: ActivatedRouteSnapshot,
state: RouterStateSnapshot):
Observable<boolean>
| Promise<boolean>
| boolean {
if(this.authService.isLoggednIn()){
this.route.navigate(["user"]);
return
true;
}else{
return
false;
}
}
}
This is also best approach to redirect if not
logged in and this one is also recommend to this option.
I hope you are enjoying with this post! Please
share with you friends! Thank you!!
|
Hey! I'm Anil Singh. I author this blog. I'm Active Blogger, Programmer. I love learning new technologies, programming, blogging and participating the forum discussions more...
|
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