Expose resolved route title

Which @angular/* package(s) are relevant/related to the feature request?

router

Description

Since Angular 14, router has a new mechanism to update page title from route config. The route can either be a static string or resolved in the same way as resolve data.

But the resolved route title is not exposed and inaccessible from client application (it seems the title is actually stored in the resolved Data, but using a private Symbol so it can’t be accessed properly).

Proposed solution

Expose a new title property on ActivatedRoute and ActivatedRouteSnapshot, just like existing params, data…

Alternatives considered

Alternative 1: Expose the internal RouteTitle symbol used to store title in Data, but this is probably not wanted because it would expose an implementation detail.

Alternative 2: Use TitleStrategy.buildTitle(snapshot: RouterStateSnapshot) or, better, TitleStrategy.getResolvedTitleForRoute(snapshot: ActivatedRouteSnapshot). But this has following drawbacks:

• TitleStrategy must be injected where we need to (only) read the route title, which is not its primary purpose…
• TitleStrategy is not very convenient to inject, because in default case, DefaultTitleStrategy is used but is not available through DI with TitleStrategy token. To get the actual strategy used, one must retrieve it from Router.titleStrategy.
• This is inconsistent with existing public api of ActivatedRoute/ActivatedRouteSnapshot

[atscott]

@EmmanuelRoux Thanks, I understand now. I appreciate the detailed explanation. It helps a lot to justify why we make the change. Even though it’s just a 1 liner in each of the ActivatedRoute and ActivatedRouteSnapshot, it’s still good to have concrete reasoning.

[EmmanuelRoux]

Sorry I was not clear!

I’m speaking here as a library author, so I have no control on the strategy the app developer will define in the app.

That said, at some point I need to know what title has been defined for a given ActivatedRoute.

What I’m saying is: in order to retrieve the title defined by the app developer, there are several choices but none of them seems good for me:

• I can read in the route config, but because the title may be a Resolve<string> this is not easy
• I can inject the TitleStrategy and call getResolvedTitleForRoute, just like your example: but this will not work if the user is using the default strategy, except by using something like this: inject(TitleStrategy, InjectFlags.Optional) || inject(DefaultTitleStrategy)
• I can read the document title (either from DOM or by using Title service): but currently nothing guarantees that a custom title strategy will actually update document title (although it is surely not a very common scenario)