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arturovt
97a3fd6a55
Without this change, components that use RouterLinkActive in multiple
contexts (e.g. both a navigation menu and body content) are forced to
branch the template for every conditional input:
@if (activeClass) {
<a [routerLink]="href" [routerLinkActive]="activeClass"
[routerLinkActiveOptions]="activeOptions"
[ariaCurrentWhenActive]="ariaCurrent">
<ng-content />
</a>
} @else {
<a [routerLink]="href"><ng-content /></a>
}
Every additional input multiplies the branching, and each @if/@else
injects unwanted comment nodes into the DOM. There is no way to
conditionally attach a directive in Angular templates, making imperative
TypeScript instantiation the only alternative.
Accepting null/undefined collapses this to a single template branch:
<a [routerLink]="href"
[routerLinkActive]="activeClass"
[routerLinkActiveOptions]="activeOptions"
[ariaCurrentWhenActive]="ariaCurrent">
<ng-content />
</a>
When activeClass is undefined (e.g. in content areas), the directive
stays mounted but applies no CSS classes. When it is a string (e.g. in
the navigation), normal active-class behavior applies — no branching, no
extra DOM nodes, no TypeScript workarounds.
- `routerLinkActive`: null/undefined now sets an empty class list.
- `routerLinkActiveOptions`: null and undefined are treated differently:
- undefined → falls back to the default subset match ("not set")
- null → explicit opt-out, link is never considered active
Closes #66233