I want my Angular 2 application to redirect to the appropriate page when a user who is logged out attempts to access a page that requires them to be logged in

Question

I want my Angular 2 application to redirect to the appropriate page when a user who is logged out attempts to access a page that requires them to be logged in

When a user is logged out in Angular 2 router and they try to navigate to a page that requires them to be logged in, I need the app.ts file to redirect them.

I am utilizing typescript along with angular 2.

Oddly enough, the redirection works for certain pages. However, when there is code in the constructor, it triggers. My goal is to immediately redirect the user to the homepage if they are not logged in.

In the app.ts file, I check if the user is logged in and initiate this code if they are not:

       this.router.navigate(['Home']);

While this method works for basic pages, accessing more complex pages like the search page generates console errors as it accesses the component's constructor.

This is the route configuration in the app.ts file:

 @RouteConfig([
     { path: '/', component: Home, as: 'Home'},
     { path: '/home', component: Home, as: 'Home' },
     { path: '/login', component: Login, as: 'Login' }, 
     { path: '/register/:id', component: Register, as: 'Register' },
     { path: '/forgotpassword', component: ForgotPassword, as: 'ForgotPassword' },
     { path: '/dashboard', component: Dashboard, as: 'Dashboard' },
     { path: '/search', component: SearchJobs, as: 'Search' },  
     {path:'/**', redirectTo: ['Home']}
 ])

typescript angular angular2-routing

Answer 1

Answer №1

While a previous post touched on this topic, I'll provide additional insight here for anyone seeking more information. One way to redirect a user is by leveraging the @CanActivate decorator in your code. This decorator will execute before the component initializes. If the function returns true, the component will load as usual; otherwise, it will trigger a redirection. Typically, the redirection will navigate the user to a specified route, usually set using useAsDefault: true;

export CanActivate(options : CanActivateAnnotation) : (hook: (next: ComponentInstruction, prev: ComponentInstruction) =>
                     Promise<boolean>| boolean) => ClassDecorator

@CanActivate((next, prev) => {
      // To allow loading of the component at this route, this condition must be met
      if(next.urlPath != '/Login'){ 
         return Promise.resolve(this._authService.getIsAuth() 
         && localStorage.getItem('authToken'))
      }
      /*
       If CanActivate returns or resolves to false, the navigation is 
       cancelled. Similarly, if there's an error thrown, or rejection occurs, 
       the navigation is halted too. On the contrary, if CanActivate returns 
       or resolves to true, the navigation continues, and the component loads 
       while triggering its OnActivate hook if implemented.
      */
   }
);

Answer 2

While a previous post touched on this topic, I'll provide additional insight here for anyone seeking more information. One way to redirect a user is by leveraging the @CanActivate decorator in your code. This decorator will execute before the component initializes. If the function returns true, the component will load as usual; otherwise, it will trigger a redirection. Typically, the redirection will navigate the user to a specified route, usually set using useAsDefault: true;

export CanActivate(options : CanActivateAnnotation) : (hook: (next: ComponentInstruction, prev: ComponentInstruction) =>
                     Promise<boolean>| boolean) => ClassDecorator

@CanActivate((next, prev) => {
      // To allow loading of the component at this route, this condition must be met
      if(next.urlPath != '/Login'){ 
         return Promise.resolve(this._authService.getIsAuth() 
         && localStorage.getItem('authToken'))
      }
      /*
       If CanActivate returns or resolves to false, the navigation is 
       cancelled. Similarly, if there's an error thrown, or rejection occurs, 
       the navigation is halted too. On the contrary, if CanActivate returns 
       or resolves to true, the navigation continues, and the component loads 
       while triggering its OnActivate hook if implemented.
      */
   }
);

Answer 3

Answer №2

To implement the required functionality, insert the following code into app.ts:

import {Router,ROUTER_PROVIDERS,RouteConfig, ROUTER_DIRECTIVES,APP_BASE_HREF,LocationStrategy,RouteParams,ROUTER_BINDINGS} from 'angular2/router';

export class AppComponent  {
    constructor(router:Router){
       this.router=router;
       this.router.subscribe((nextValue) => {
       console.log(nextValue)
       if (nextValue !== 'login' && !autheService.isAuthenticated) {
                      this.router.navigate(['/Login']);
       }
}

Check out the example

 <a href="https://plnkr.co/edit/NbGy8gxmy5DdLhoiHw8h?p=preview" rel="nofollow">plunker here</a>

If you are familiar with Angular1, a similar approach would be:

$scope.$on('$routeChangeStart', function(next, current) { 
   ... you could trigger something here ...
 });

You can utilize other events provided by ui.router to handle routing errors and failures. Consider replacing Angular1 with the above code snippet for a seamless transition.

This solution should address your requirements efficiently. However, do remember to look into @canActive and consider other valid points.

I trust that this information proves helpful.

Answer 4

To implement the required functionality, insert the following code into app.ts:

import {Router,ROUTER_PROVIDERS,RouteConfig, ROUTER_DIRECTIVES,APP_BASE_HREF,LocationStrategy,RouteParams,ROUTER_BINDINGS} from 'angular2/router';

export class AppComponent  {
    constructor(router:Router){
       this.router=router;
       this.router.subscribe((nextValue) => {
       console.log(nextValue)
       if (nextValue !== 'login' && !autheService.isAuthenticated) {
                      this.router.navigate(['/Login']);
       }
}

Check out the example

 <a href="https://plnkr.co/edit/NbGy8gxmy5DdLhoiHw8h?p=preview" rel="nofollow">plunker here</a>

If you are familiar with Angular1, a similar approach would be:

$scope.$on('$routeChangeStart', function(next, current) { 
   ... you could trigger something here ...
 });

You can utilize other events provided by ui.router to handle routing errors and failures. Consider replacing Angular1 with the above code snippet for a seamless transition.

This solution should address your requirements efficiently. However, do remember to look into @canActive and consider other valid points.

I trust that this information proves helpful.

Answer 5

Answer №3

If you are using the RC4 version, make sure to refer to the CanActivate interface for guidance.

To secure your routes, you will need to create a class that implements the CanActivate interface and utilize the canActivate property in the RouterConfig.

For more detailed examples, consult the latest router documentation.

Answer 6

If you are using the RC4 version, make sure to refer to the CanActivate interface for guidance.

To secure your routes, you will need to create a class that implements the CanActivate interface and utilize the canActivate property in the RouterConfig.

For more detailed examples, consult the latest router documentation.

I want my Angular 2 application to redirect to the appropriate page when a user who is logged out attempts to access a page that requires them to be logged in

Answer №1

Answer №2

Answer №3

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