Introduce behavior

Source/Nalu.Maui.Navigation/Interfaces/INavigationConfiguration.cs

@@ -15,6 +15,11 @@ public interface INavigationConfiguration
     /// </summary>
     ImageSource? BackImage { get; }
 
+    /// <summary>
+    /// Gets the navigation intent behavior.
+    /// </summary>
+    NavigationIntentBehavior NavigationIntentBehavior { get; }
+
     /// <summary>
     /// Gets a dictionary which maps a page model type to corresponding page type.
     /// </summary>

Source/Nalu.Maui.Navigation/Interfaces/NavigationIntentBehavior.cs

@@ -0,0 +1,31 @@
+namespace Nalu;
+
+/// <summary>
+/// Defines how lifecycle events are triggered when a navigation intent is detected.
+/// </summary>
+public enum NavigationIntentBehavior
+{
+    /// <summary>
+    /// When a navigation intent is detected, only intent-related navigation lifecycle events will be triggered.
+    /// </summary>
+    /// <example>
+    /// In the following example, if <c>MyIntent</c> is detected, the navigation will invoke only <c>OnAppearingAsync(MyIntent)</c>.
+    /// <code>
+    /// public ValueTask OnEnteringAsync()
+    /// public ValueTask OnAppearingAsync(MyIntent)
+    /// </code>
+    /// </example>
+    Strict,
+
+    /// <summary>
+    /// When a navigation intent is detected, if the corresponding intent-related navigation lifecycle event is not defined, the navigation will fall through to the generic one.
+    /// </summary>
+    /// <example>
+    /// In the following example, if <c>MyIntent</c> is detected, the navigation will invoke <c>OnEnteringAsync</c> and <c>OnAppearingAsync(MyIntent)</c> in sequence.
+    /// <code>
+    /// public ValueTask OnEnteringAsync()
+    /// public ValueTask OnAppearingAsync(MyIntent)
+    /// </code>
+    /// </example>
+    Fallthrough,
+}

Source/Nalu.Maui.Navigation/Internals/NavigationHelper.cs

@@ -7,7 +7,7 @@ internal static class NavigationHelper
     private static readonly MethodInfo _sendEnteringWithIntentAsyncMethod = typeof(NavigationHelper).GetMethod(nameof(SendEnteringWithIntentAsync), BindingFlags.NonPublic | BindingFlags.Static)!;
     private static readonly MethodInfo _sendAppearingWithIntentAsyncMethod = typeof(NavigationHelper).GetMethod(nameof(SendAppearingWithIntentAsync), BindingFlags.NonPublic | BindingFlags.Static)!;
 
-    public static ValueTask SendEnteringAsync(Page page, object? intent)
+    public static ValueTask SendEnteringAsync(Page page, object? intent, INavigationConfiguration configuration)
     {
         var context = PageNavigationContext.Get(page);
         if (context.Entered)
@@ -30,7 +30,10 @@ public static ValueTask SendEnteringAsync(Page page, object? intent)
                 return (ValueTask)_sendEnteringWithIntentAsyncMethod.MakeGenericMethod(intentType).Invoke(null, [target, intent])!;
             }
 
-            return ValueTask.CompletedTask;
+            if (configuration.NavigationIntentBehavior == NavigationIntentBehavior.Strict)
+            {
+                return ValueTask.CompletedTask;
+            }
         }
 
         if (target is IEnteringAware enteringAware)
@@ -67,7 +70,7 @@ public static ValueTask SendLeavingAsync(Page page)
         return ValueTask.CompletedTask;
     }
 
-    public static ValueTask SendAppearingAsync(Page page, object? intent)
+    public static ValueTask SendAppearingAsync(Page page, object? intent, INavigationConfiguration configuration)
     {
         var context = PageNavigationContext.Get(page);
         if (context.Appeared)
@@ -91,7 +94,10 @@ public static ValueTask SendAppearingAsync(Page page, object? intent)
                 return (ValueTask)_sendAppearingWithIntentAsyncMethod.MakeGenericMethod(intentType).Invoke(null, [target, intent])!;
             }
 
-            return ValueTask.CompletedTask;
+            if (configuration.NavigationIntentBehavior == NavigationIntentBehavior.Strict)
+            {
+                return ValueTask.CompletedTask;
+            }
         }
 
         if (target is IAppearingAware appearingAware)

Source/Nalu.Maui.Navigation/Internals/NavigationService.cs

@@ -44,7 +44,7 @@ public async Task InitializeAsync(IShellProxy shellProxy, string contentSegmentN
 
         NavigationHelper.AssertIntent(page, intent, content.DestroyContent);
 
-        var enteringTask = NavigationHelper.SendEnteringAsync(page, intent).AsTask();
+        var enteringTask = NavigationHelper.SendEnteringAsync(page, intent, Configuration).AsTask();
         if (!enteringTask.IsCompleted)
         {
             throw new NotSupportedException($"OnEnteringAsync() must not be async for the initial page {page.BindingContext!.GetType().FullName}.");
@@ -56,7 +56,7 @@ public async Task InitializeAsync(IShellProxy shellProxy, string contentSegmentN
         await _shellProxy.SelectContentAsync(contentSegmentName).ConfigureAwait(true);
 #pragma warning restore VSTHRD002
 
-        await NavigationHelper.SendAppearingAsync(page, intent).ConfigureAwait(true);
+        await NavigationHelper.SendAppearingAsync(page, intent, Configuration).ConfigureAwait(true);
     }
 
     public async Task<bool> GoToAsync(INavigationInfo navigation)
@@ -186,7 +186,7 @@ private async Task<bool> ExecuteRelativeNavigationAsync(
                     await shellProxy.CommitNavigationAsync().ConfigureAwait(true);
                     shellProxy.BeginNavigation();
 
-                    await NavigationHelper.SendAppearingAsync(stackPage.Page, null).ConfigureAwait(true);
+                    await NavigationHelper.SendAppearingAsync(stackPage.Page, null, Configuration).ConfigureAwait(true);
                     var canLeave = await NavigationHelper.CanLeaveAsync(stackPage.Page).ConfigureAwait(true);
                     if (!canLeave)
                     {
@@ -211,7 +211,7 @@ private async Task<bool> ExecuteRelativeNavigationAsync(
                 var page = CreatePage(pageType, stackPage.Page, Configuration.BackImage);
 
                 var isModal = Shell.GetPresentationMode(page).HasFlag(PresentationMode.Modal);
-                await NavigationHelper.SendEnteringAsync(page, intent).ConfigureAwait(true);
+                await NavigationHelper.SendEnteringAsync(page, intent, Configuration).ConfigureAwait(true);
                 await shellProxy.PushAsync(segmentName, page).ConfigureAwait(true);
                 stack.Add(new NavigationStackPage($"{stackPage.Route}/{segmentName}", segmentName, page, isModal));
             }
@@ -226,7 +226,7 @@ private async Task<bool> ExecuteRelativeNavigationAsync(
             shellProxy.BeginNavigation();
 
             NavigationHelper.AssertIntent(page, intent);
-            await NavigationHelper.SendAppearingAsync(page, intent).ConfigureAwait(true);
+            await NavigationHelper.SendAppearingAsync(page, intent, Configuration).ConfigureAwait(true);
         }
 
         return true;
@@ -373,7 +373,7 @@ private async Task<bool> ExecuteCrossContentNavigationAsync(
                     await shellProxy.CommitNavigationAsync().ConfigureAwait(true);
                     shellProxy.BeginNavigation();
 
-                    await NavigationHelper.SendAppearingAsync(contentPage, null).ConfigureAwait(true);
+                    await NavigationHelper.SendAppearingAsync(contentPage, null, Configuration).ConfigureAwait(true);
                     if (!await NavigationHelper.CanLeaveAsync(contentPage).ConfigureAwait(true))
                     {
                         return false;
@@ -408,7 +408,7 @@ Task EnsureContentIsSelectedAsync()
         var targetContentPage = targetContent.GetOrCreateContent();
         var targetIsShellContent = navigation.Count == 1;
         var intent = targetIsShellContent ? navigation.Intent : null;
-        await NavigationHelper.SendEnteringAsync(targetContentPage, intent).ConfigureAwait(true);
+        await NavigationHelper.SendEnteringAsync(targetContentPage, intent, Configuration).ConfigureAwait(true);
         await ShellProxy.SelectContentAsync(targetContent.SegmentName).ConfigureAwait(true);
 
         if (!targetIsShellContent)
@@ -422,7 +422,7 @@ Task EnsureContentIsSelectedAsync()
         }
 
         await shellProxy.CommitNavigationAsync().ConfigureAwait(true);
-        await NavigationHelper.SendAppearingAsync(targetContentPage, intent).ConfigureAwait(true);
+        await NavigationHelper.SendAppearingAsync(targetContentPage, intent, Configuration).ConfigureAwait(true);
         return true;
     }
 

Source/Nalu.Maui.Navigation/NavigationConfigurator.cs

@@ -18,6 +18,9 @@ public class NavigationConfigurator : INavigationConfiguration
     /// <inheritdoc />
     public ImageSource? BackImage { get; private set; }
 
+    /// <inheritdoc />
+    public NavigationIntentBehavior NavigationIntentBehavior { get; private set; }
+
     /// <inheritdoc />
     public IReadOnlyDictionary<Type, Type> Mapping => _mapping;
 
@@ -61,6 +64,16 @@ public NavigationConfigurator WithMenuImage(ImageSource imageSource)
         return this;
     }
 
+    /// <summary>
+    /// Defines how lifecycle events should be handled when an intent is detected.
+    /// </summary>
+    /// <param name="behavior">The behavior to use.</param>
+    public NavigationConfigurator WithNavigationIntentBehavior(NavigationIntentBehavior behavior)
+    {
+        NavigationIntentBehavior = behavior;
+        return this;
+    }
+
     /// <summary>
     /// Registers <typeparamref name="TPage"/> as the view for <typeparamref name="TPageModel"/>.
     /// Adds <typeparamref name="TPage"/> and <typeparamref name="TPageModel"/> as scoped services.