docs: HowTo IRouteNotifier

doc/Learn/Navigation/Advanced/HowTo-IRouteNotifier.md

@@ -0,0 +1,59 @@
+---
+uid: Uno.Extensions.Navigation.Advanced.IRouteNotifier
+---
+# How-To: Use `IRouteNotifier` to Handle Route Changes
+
+The `IRouteNotifier` interface allows you to track and respond to route changes through the `RouteChanged` event. This guide will show you how to use `IRouteNotifier` to handle route changes and improve your app's navigation.
+
+## Step-by-steps
+
+[!include[create-application](../../includes/create-application.md)]
+
+### How to Use `IRouteNotifier` to Monitor Route Changes
+
+The `IRouteNotifier` provides an effective way to monitor and respond to route changes within your application. To begin using `IRouteNotifier`, ensure your class has access to an instance of an `IRouteNotifier` implementation. Add a parameter of type `IRouteNotifier` to the constructor of your class where you want to monitor route changes.
+
+```csharp
+public class MyClass
+{
+    private readonly IRouteNotifier _notifier;
+
+    public MyClass(IRouteNotifier notifier)
+    {
+        _notifier = notifier;
+        _notifier.RouteChanged += RouteChanged;
+    }
+
+    private async void RouteChanged(object? sender, RouteChangedEventArgs e)
+    {
+        // Implement your logic to handle route change here
+    }
+}
+```
+
+It's possible to access the `IRouteNotifier` service directly from `App.xaml.cs` or anywhere you have access to the `IHost` to retrieve services. This allows you to subscribe to route changes and respond accordingly in your application.
+
+For example, in `App.xaml.cs`:
+
+```csharp
+...
+Host = await builder.NavigateAsync<Shell>();
+
+var notifier = Host.Services.GetService<IRouteNotifier>();
+notifier.RouteChanged += (s, e) =>
+{
+    Debug.WriteLine($"Navigated to {e.Region?.Name}");
+};
+```
+
+### Access `INavigator` through `IRouteNotifier`
+
+It's possible to access an `INavigator` through the `RouteChanged` event provided by the `IRouteNotifier`. This can be particularly useful when you need to handle navigation within dynamic scenarios, such as managing modals, dialogs, or conditional navigation flows.
+
+```csharp
+private async void RouteChanged(object? sender, RouteChangedEventArgs e)
+{
+    var navigator = e.Navigator;
+    // Logic to use `INavigator` here
+}
+```

doc/Learn/Navigation/toc.yml

@@ -32,3 +32,5 @@
       href: xref:Uno.Extensions.Navigation.Advanced.Panel
     - name: "How-To: Navigate using a ContentControl"
       href: xref:Uno.Extensions.Navigation.Advanced.ContentControl
+    - name: "How-To: Use IRouteNotifier to Handle Route Changes"
+      href: xref:Uno.Extensions.Navigation.Advanced.IRouteNotifier