In Angular, how do you determine the active route?

In Angular, how do you determine the active route?

NOTE: There are many different answers here, and most have been valid at one time or another. The fact is that what works has changed a number of times as the Angular team has changed its Router. The Router 3.0 version that will eventually be the router in Angular breaks many of these solutions, but offers a very simple solution of its own. As of RC.3, the preferred solution is to use [routerLinkActive] as shown in this answer.
In an Angular application (current in the 2.0.0-beta.0 release as I write this), how do you determine what the currently active route is?
I’m working on an app that uses Bootstrap 4 and I need a way to mark navigation links/buttons as active when their associated component is being shown in a tag.
I realize that I could maintain the state myself when one of the buttons is clicked upon, but that wouldn’t cover the case of having multiple paths into the same route (say a main navigation menu as well as a local menu in the main component).
Any suggestions or links would be appreciated. Thanks.

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Solutions/Answers:

Solution 1:

With the new Angular router, you can add a [routerLinkActive]="['your-class-name']" attribute to all your links:

<a [routerLink]="['/home']" [routerLinkActive]="['is-active']">Home</a>

Or the simplified non-array format if only one class is needed:

<a [routerLink]="['/home']" [routerLinkActive]="'is-active'">Home</a>

See the poorly documented routerLinkActive directive for more info. (I mostly figured this out via trial-and-error.)

UPDATE: Better documentation for the routerLinkActive directive can now be found here. (Thanks to @Victor Hugo Arango A. in the comments below.)

Solution 2:

I’ve replied this in another question but I believe it might be relevant to this one as well. Here’s a link to the original answer:
Angular 2: How to determine active route with parameters?

I’ve been trying to set the active class without having to know exactly what’s the current location (using the route name). The is the best solution I have got to so far is using the function isRouteActive available in the Router class.

router.isRouteActive(instruction): Boolean takes one parameter which is a route Instruction object and returns true or false whether that instruction holds true or not for the current route. You can generate a route Instruction by using Router‘s generate(linkParams: Array). LinkParams follows the exact same format as a value passed into a routerLink directive (e.g. router.isRouteActive(router.generate(['/User', { user: user.id }])) ).

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This is how the RouteConfig could look like (I’ve tweaked it a bit to show the usage of params):

@RouteConfig([
  { path: '/', component: HomePage, name: 'Home' },
  { path: '/signin', component: SignInPage, name: 'SignIn' },
  { path: '/profile/:username/feed', component: FeedPage, name: 'ProfileFeed' },
])

And the View would look like this:

<li [class.active]="router.isRouteActive(router.generate(['/Home']))">
   <a [routerLink]="['/Home']">Home</a>
</li>
<li [class.active]="router.isRouteActive(router.generate(['/SignIn']))">
   <a [routerLink]="['/SignIn']">Sign In</a>
</li>
<li [class.active]="router.isRouteActive(router.generate(['/ProfileFeed', { username: user.username }]))">
    <a [routerLink]="['/ProfileFeed', { username: user.username }]">Feed</a>
</li>

This has been my preferred solution for the problem so far, it might be helpful for you as well.

Solution 3:

I solved a problem I encountered in this link and I find out that there is a simple solution for your question. You could use router-link-active instead in your styles.

@Component({
   styles: [`.router-link-active { background-color: red; }`]
})
export class NavComponent {
}

Solution 4:

Small improvement to @alex-correia-santos answer based on https://github.com/angular/angular/pull/6407#issuecomment-190179875

import {Router, RouteConfig, ROUTER_DIRECTIVES} from 'angular2/router';
// ...
export class App {
  constructor(private router: Router) {
  }

  // ...

  isActive(instruction: any[]): boolean {
    return this.router.isRouteActive(this.router.generate(instruction));
  }
} 

And use it like this:

<ul class="nav navbar-nav">
    <li [class.active]="isActive(['Home'])">
        <a [routerLink]="['Home']">Home</a>
    </li>
    <li [class.active]="isActive(['About'])">
        <a [routerLink]="['About']">About</a>
    </li>
</ul>

Solution 5:

You can check the current route by injecting the Location object into your controller and checking the path(), like so:

class MyController {
    constructor(private location:Location) {}

    ...  location.path(); ...
}

You will have to make sure to import it first:

import {Location} from "angular2/router";

You can then use a regular expression to match against the path that’s returned to see which route is active. Note that the Location class returns a normalized path regardless of which LocationStrategy you’re using. So even if you’re using the HashLocationStragegy the paths returned will still be of the form /foo/bar not #/foo/bar

Solution 6:

how do you determine what the currently active route is?

UPDATE: updated as per Angular2.4.x

constructor(route: ActivatedRoute) {
   route.snapshot.params; // active route's params

   route.snapshot.data; // active route's resolved data

   route.snapshot.component; // active route's component

   route.snapshot.queryParams // The query parameters shared by all the routes
}

see more…

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