Retrieve the value of [routerLinkActive] in the component's class

Question

Retrieve the value of [routerLinkActive] in the component's class

Recently, I've been working on a tab component called TabComponent and it includes the following HTML template:

<a [routerLink]='link' [routerLinkActive]="[is-active]">link label</a>
<button>Close tab</button>

The challenge I'm facing is how to access the value of the [routerLinkActive] property within the component class. Essentially, I need to retrieve a variable that indicates whether this routerLink is currently active. Any suggestions on how to achieve this?

UPDATE: I have started thinking that if I could somehow access the CSS class of the <a> link tag, it might solve my problem. Is there a way to do this?

javascript typescript angular

Answer 1

Answer №1

If you're looking to extract values from your template, here's a helpful tip:

<a *ngFor="let child of directory; let i = index;"
   routerLink="{{child.route}}"
   routerLinkActive #rla="routerLinkActive">

   <h3>{{rla.isActive}}</h3><!--This will show a boolean indicating if you are on this link-->
</a>

By including the above code in your template, the h3 element will reflect whether you are currently on the linked page.

Although this method works within the template, I've encountered difficulties passing this value to component.ts or to other directives in the template:

<a *ngFor="let child of directory; let i = index;"
   routerLink="{{child.route}}"
   routerLinkActive #rla="routerLinkActive"

   [active]="rla.isActive" <!--Unfortunately, this doesn't insert the boolean as expected-->
   >    
   <h3>{{rla.isActive}}</h3>
</a>

I hope this information proves useful. Feel free to share any progress made towards finding a solution.

Answer 2

If you're looking to extract values from your template, here's a helpful tip:

<a *ngFor="let child of directory; let i = index;"
   routerLink="{{child.route}}"
   routerLinkActive #rla="routerLinkActive">

   <h3>{{rla.isActive}}</h3><!--This will show a boolean indicating if you are on this link-->
</a>

By including the above code in your template, the h3 element will reflect whether you are currently on the linked page.

Although this method works within the template, I've encountered difficulties passing this value to component.ts or to other directives in the template:

<a *ngFor="let child of directory; let i = index;"
   routerLink="{{child.route}}"
   routerLinkActive #rla="routerLinkActive"

   [active]="rla.isActive" <!--Unfortunately, this doesn't insert the boolean as expected-->
   >    
   <h3>{{rla.isActive}}</h3>
</a>

I hope this information proves useful. Feel free to share any progress made towards finding a solution.

Answer 3

Answer №2

If you want to access the isActive state within a component, you must wait for the AfterContentChecked lifecycle hook.

<a routerLink="/user/john" routerLinkActive #rla="routerLinkActive">
  John {{ rla.isActive ? '(active)' : ''}}
</a>

@ViewChild('rla') private rla: RouterLinkActive;

ngAfterContentChecked(): void {
    if (this.rla?.isActive) {
        console.log('isActive')
    }
}

Answer 4

If you want to access the isActive state within a component, you must wait for the AfterContentChecked lifecycle hook.

<a routerLink="/user/john" routerLinkActive #rla="routerLinkActive">
  John {{ rla.isActive ? '(active)' : ''}}
</a>

@ViewChild('rla') private rla: RouterLinkActive;

ngAfterContentChecked(): void {
    if (this.rla?.isActive) {
        console.log('isActive')
    }
}

Answer 5

Answer №3

To access routerLinkActive, you can utilize the @ViewChild() decorator.

@ViewChild(RouterLinkActive) private routerLinkActive: RouterLinkActive;

The issue lies in the fact that its values are not immediately set. This means that during component rendering, isActive will likely be false initially, with the Router only updating it to true later on.

Answer 6

To access routerLinkActive, you can utilize the @ViewChild() decorator.

@ViewChild(RouterLinkActive) private routerLinkActive: RouterLinkActive;

The issue lies in the fact that its values are not immediately set. This means that during component rendering, isActive will likely be false initially, with the Router only updating it to true later on.

Answer 7

Answer №4

In addition to Nayfin's response, I have also successfully implemented this method in Angular 11.

This technique involves using a template variable to assign a property, rather than utilizing ngFor. It is important to note that a unique template variable must be used for each component.

<a routerLink="/route1" routerLinkActive #route1RLA="routerLinkActive" [active]="route1RLA.isActive">Route 1</a>
<a routerLink="/route2" routerLinkActive #route2RLA="routerLinkActive" [active]="route2RLA.isActive">Route 2</a>
<a routerLink="/route3" routerLinkActive #route3RLA="routerLinkActive" [active]="route3RLA.isActive">Route 3</a>

Answer 8

In addition to Nayfin's response, I have also successfully implemented this method in Angular 11.

This technique involves using a template variable to assign a property, rather than utilizing ngFor. It is important to note that a unique template variable must be used for each component.

<a routerLink="/route1" routerLinkActive #route1RLA="routerLinkActive" [active]="route1RLA.isActive">Route 1</a>
<a routerLink="/route2" routerLinkActive #route2RLA="routerLinkActive" [active]="route2RLA.isActive">Route 2</a>
<a routerLink="/route3" routerLinkActive #route3RLA="routerLinkActive" [active]="route3RLA.isActive">Route 3</a>

Retrieve the value of [routerLinkActive] in the component's class

Answer №1

Answer №2

Answer №3

Answer №4

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