This commit provides a replacement for `$location`. The new service is written in Angular, and can be consumed into existing applications by using the downgraded version
of the provider.
Prior to this addition, applications upgrading from AngularJS to Angular could get into a situation where AngularJS wanted to control the URL, and would often parse or se
rialize the URL in a different way than Angular. Additionally, AngularJS was alerted to URL changes only through the `$digest` cycle. This provided a buggy feedback loop
from Angular to AngularJS.
With this new `LocationUpgradeProvider`, the `$location` methods and events are provided in Angular, and use Angular APIs to make updates to the URL. Additionally, change
s to the URL made by other parts of the Angular framework (such as the Router) will be listened for and will cause events to fire in AngularJS, but will no longer attempt
to update the URL (since it was already updated by the Angular framework).
This centralizes URL reads and writes to Angular and should help provide an easier path to upgrading AngularJS applications to Angular.
PR Close#30055
This feature adds an `onUrlChange` to Angular's `Location` class. This is useful to track all updates coming from anywhere in the framework. Without this method, it's difficult (or impossible) to track updates run through `location.go()` or `location.replaceState()` as the browser doesn't publish events when `history.pushState()` or `.replaceState()` are run.
PR Close#30055
Previously there wasn't a way to retrieve `history.state` from the `Location` service. The only time the framework exposed this value was in navigation events. This meant if you weren't using the Angular router, there wasn't a way to get access to this `history.state` value other than going directly to the DOM.
This PR adds an API to retrieve the value of `history.state`. This will be useful and needed to provide a backwards-compatible `Location` service that can emulate AngularJS's `$location` service since we will need to be able to read the state data in order to produce AngularJS location transition events.
This feature will additionally be useful to any application that wants to access state data through Angular rather than going directly to the DOM APIs.
PR Close#30055