GeezerVison

    
      class RouterLinkWithHref implements OnChanges ,OnDestroy {}
    
    

When applied to an element in a template, makes that element a link that initiates navigation to a route. Navigation opens one or more routed components in one or more <router-outlet> locations on the page.

Given a route configuration [{ path: 'user/:name', component: UserCmp }], the following creates a static link to the route: <a routerLink="/user/bob">link to user component</a>

You can use dynamic values to generate the link. For a dynamic link, pass an array of path segments, followed by the params for each segment. For example, ['/team', teamId, 'user', userName, {details: true}] generates a link to /team/11/user/bob;details=true.

Multiple static segments can be merged into one term and combined with dynamic segments. For example, ['/team/11/user', userName, {details: true}]

The input that you provide to the link is treated as a delta to the current URL. For instance, suppose the current URL is /user/(box//aux:team). The link <a [routerLink]="['/user/jim']">Jim</a> creates the URL /user/(jim//aux:team). See Router#createUrlTree for more information.

You can use absolute or relative paths in a link, set query parameters, control how parameters are handled, and keep a history of navigation states.

Relative link paths

The first segment name can be prepended with /, ./, or ../.

• If the first segment begins with /, the router looks up the route from the root of the app.
• If the first segment begins with ./, or doesn't begin with a slash, the router looks in the children of the current activated route.
• If the first segment begins with ../, the router goes up one level in the route tree.

Setting and handling query params and fragments

The following link adds a query parameter and a fragment to the generated URL:

<a [routerLink]="['/user/bob']" [queryParams]="{debug: true}"
fragment="education"> link to user component
</a>

By default, the directive constructs the new URL using the given query parameters. The example generates the link: /user/bob?debug=true#education.

You can instruct the directive to handle query parameters differently by specifying the queryParamsHandling option in the link. Allowed values are:

• 'merge': Merge the given queryParams into the current query params.
• 'preserve': Preserve the current query params.

For example:

<a [routerLink]="['/user/bob']" [queryParams]="{debug: true}"
queryParamsHandling="merge"> link to user component
</a>

queryParams, fragment, queryParamsHandling, preserveFragment, and relativeTo cannot be used when the routerLink input is a UrlTree.

See UrlCreationOptions#queryParamsHandling.

Preserving navigation history

You can provide a state value to be persisted to the browser's History.state property. For example:

<a [routerLink]="['/user/bob']" [state]="{tracingId: 123}">
  link to user component
</a>

Use Router#currentNavigation to retrieve a saved Signal navigation-state value. For example, to capture the tracingId during the NavigationStart event:

// Get NavigationStart events
router.events.pipe(filter(e => e instanceof NavigationStart)).subscribe(e => {
  const navigation = router.currentNavigation();
  tracingService.trace({id: navigation.extras.state.tracingId});
});

Controlling scrolling

When scroll restoration is enabled with withInMemoryScrolling, every navigation scrolls, even one that only changes a query param. Set scroll to 'manual' to opt a link out, for example for tabs further down the page:

<a routerLink="/products/42" [queryParams]="{tab: 'reviews'}" scroll="manual">Reviews</a>

RouterLink compatible custom elements

In order to make a custom element work with routerLink, the corresponding custom element must implement the href attribute and must list href in the array of the static property/getter observedAttributes.