Improvements to Page Api for navigation

[emmauss]

Is your feature request related to a problem? Please describe.

Current Page api for navigation is limited requiring the host to instantiate the page before passing it to the INavigation instance. Services that want to detach themselves from views have to use factories as middlemen to create page instances to navigate to.

Describe the solution you'd like

Add the following api to INavigation

Task PushAsync(Page page, IPageTransition? transition, object? parameter);

Task ReplaceAsync(Page page, IPageTransition? transition, object? parameter);

Task PushModalAsync(Page page, IPageTransition? transition, object? parameter);

NavigatingFromEventArgs, NavigatingToEventArgs, NavigatedFromEventArgs, NavigatedToEventArgs, NavigationEventArgs`

public object? Parameter { get; }

public static class PageNavigationExtensions
{
    extension(INavigation navigation)
    {
        /// <summary>
        /// Pushes a new page of type <typeparamref name="T"/> onto the navigation stack, using <paramref name="transition"/> with optional <paramref name="parameter"/>.
        /// </summary>
        public Task PushAsync<T>(IPageTransition? transition = null, object? parameter = null) where T : Page, new();

        /// <summary>
        /// Replaces the current top page with a new page of type <typeparamref name="T"/>, using <paramref name="transition"/> with optional <paramref name="parameter"/>.
        /// </summary>
        public Task ReplaceAsync<T>(IPageTransition? transition = null, object? parameter = null) where T : Page, new();

        /// <summary>
        /// Pushes a new modal page of type <typeparamref name="T"/> onto the modal stack, using <paramref name="transition"/> with optional <paramref name="parameter"/>.
        /// </summary>
        public Task PushModalAsync<T>(IPageTransition? transition = null, object? parameter = null) where T : Page, new();
    }
}

The parameter value is set in the Navigating args and is read by the page on navigating to or from.

Describe alternatives you've considered

No response

Additional context

No response

[emmauss]

Draft implementation #22010

[MrJul]

Notes from the API review meeting:

• Make parameter nullable
• Keep only the non-generic overload for each method as part INavigation: e.g. Task PushAsync(Page page, IPageTransition? transition, object? parameter) for PushAsync.
• Move the other overloads to a PageNavigationExtensions class. Merge the 4 overloads into a single one with optional parameters, e.g. Task PushAsync<T>(IPageTransition? transition = null, object? parameter = null) where T : Page, new();

[emmauss]

Updated