[Core] Can bind properties in BindableObjects added to static resources in XAML (#58)

Resources that are `BindableObject`s will inherit the `Parent`'s `BindingContext` unless they are `Element`s that have non-null `Parent`s.

5 files changed, 160 insertions, 1 deletions

diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla23942.xaml b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla23942.xaml
new file mode 100644
index 00000000..d207cd23
--- /dev/null
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla23942.xaml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<local:TestContentPage xmlns="http://xamarin.com/schemas/2014/forms"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+			 xmlns:test="clr-namespace:Xamarin.Forms.Controls.Issues"
+			 xmlns:local="clr-namespace:Xamarin.Forms.Controls"
+             x:Class="Xamarin.Forms.Controls.Issues.Bugzilla23942">
+
+	<local:TestContentPage.Resources>
+		<ResourceDictionary>
+			<test:Bugzilla23942Options x:Key="opts" 
+										Text="{Binding DoesItWork}" />
+		</ResourceDictionary>
+	</local:TestContentPage.Resources>
+
+	<local:TestContentPage.Content>
+		<StackLayout>
+			<test:Bugzilla23942Label x:Name="label"  Options="{DynamicResource opts}" />
+		</StackLayout>
+	</local:TestContentPage.Content>
+
+</local:TestContentPage>
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla23942.xaml.cs b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla23942.xaml.cs
new file mode 100644
index 00000000..efa78941
--- /dev/null
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla23942.xaml.cs
@@ -0,0 +1,111 @@
+using Xamarin.Forms;
+using Xamarin.Forms.CustomAttributes;
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 23942, "Cannot bind properties in BindableObjects added to static resources in XAML", PlatformAffected.All)]
+	public partial class Bugzilla23942 : TestContentPage
+	{
+		[Preserve(AllMembers = true)]
+		public class TestViewModel : ViewModelBase
+		{
+			string _doesItWork;
+			public string DoesItWork
+			{
+				get
+				{
+					return _doesItWork;
+				}
+				set
+				{
+					_doesItWork = value;
+					OnPropertyChanged();
+				}
+			}
+		}
+
+#if APP
+		public Bugzilla23942()
+		{
+			InitializeComponent();
+		}
+#endif
+
+		private void InitializeView()
+		{
+			TestViewModel vm = new TestViewModel() { DoesItWork = "initial binding works" };
+			BindingContext = vm;
+			vm.DoesItWork = "success";
+		}
+
+		protected override void Init()
+		{
+			InitializeView();
+		}
+
+		protected override void OnAppearing()
+		{
+			base.OnAppearing();
+			var lbl = this.FindByName<Bugzilla23942Label>("label");
+			lbl.Text = lbl.Options.Text;
+		}
+
+#if UITEST
+		[Test]
+		public void Bugzilla23942Test()
+		{
+			RunningApp.WaitForElement(q => q.Marked("success"));
+		}
+#endif
+	}
+
+	[Preserve(AllMembers = true)]
+	public class Bugzilla23942Options : BindableObject
+	{
+		public static readonly BindableProperty TextProperty =
+			BindableProperty.Create(propertyName: nameof(Text),
+									returnType: typeof(string),
+									declaringType: typeof(Bugzilla23942Options),
+									defaultValue: default(string));
+
+		public string Text
+		{
+			get
+			{
+				return (string)GetValue(TextProperty);
+			}
+			set
+			{
+				SetValue(TextProperty, value);
+			}
+		}
+	}
+
+	[Preserve(AllMembers = true)]
+	public class Bugzilla23942Label : Label
+	{
+		public static readonly BindableProperty OptionsProperty =
+			BindableProperty.Create(propertyName: nameof(Options),
+									returnType: typeof(Bugzilla23942Options),
+									declaringType: typeof(Bugzilla23942Label),
+									defaultValue: default(Bugzilla23942Options));
+
+		public Bugzilla23942Options Options
+		{
+			get
+			{
+				return (Bugzilla23942Options)GetValue(OptionsProperty);
+			}
+			set
+			{
+				SetValue(OptionsProperty, value);
+			}
+		}
+	}
+}
diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
index ca43a273..6a1e0b93 100644
--- a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
@@ -18,6 +18,9 @@
       <DependentUpon>Bugzilla22229.xaml</DependentUpon>
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla22401.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Bugzilla23942.xaml.cs">
+      <DependentUpon>Bugzilla23942.xaml</DependentUpon>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla24769.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla25234.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla25662.cs" />
@@ -516,6 +519,12 @@
     </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
+    <EmbeddedResource Include="$(MSBuildThisFileDirectory)Bugzilla23942.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
+  </ItemGroup>
+  <ItemGroup>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Bugzilla39636.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
diff --git a/Xamarin.Forms.Core/BindableObject.cs b/Xamarin.Forms.Core/BindableObject.cs
index 683d390a..f3482004 100644
--- a/Xamarin.Forms.Core/BindableObject.cs
+++ b/Xamarin.Forms.Core/BindableObject.cs
@@ -360,7 +360,7 @@ namespace Xamarin.Forms
 
 			if (fromStyle)
 				context.Attributes |= BindableContextAttributes.IsSetFromStyle;
-			// else ommitted on purpose
+			// else omitted on purpose
 
 			bool currentlyApplying = _applying;
 
diff --git a/Xamarin.Forms.Core/Element.cs b/Xamarin.Forms.Core/Element.cs
index a85bb3fb..b6312737 100644
--- a/Xamarin.Forms.Core/Element.cs
+++ b/Xamarin.Forms.Core/Element.cs
@@ -17,6 +17,8 @@ namespace Xamarin.Forms
 
 		string _automationId;
 
+		IList<BindableObject> _bindableResources;
+
 		List<Action<object, ResourcesChangedEventArgs>> _changeHandlers;
 
 		List<KeyValuePair<string, BindableProperty>> _dynamicResources;
@@ -321,6 +323,12 @@ namespace Xamarin.Forms
 				SetChildInheritedBindingContext(child, bc);
 			}
 
+			if (_bindableResources != null)
+				foreach (BindableObject item in _bindableResources)
+				{
+					SetInheritedBindingContext(item, BindingContext);
+				}
+
 			base.OnBindingContextChanged();
 		}
 
@@ -420,6 +428,8 @@ namespace Xamarin.Forms
 					handler(this, new ResourcesChangedEventArgs(values));
 			if (_dynamicResources == null)
 				return;
+			if (_bindableResources == null)
+				_bindableResources = new List<BindableObject>();
 			foreach (KeyValuePair<string, object> value in values)
 			{
 				List<BindableProperty> changedResources = null;
@@ -434,6 +444,14 @@ namespace Xamarin.Forms
 					continue;
 				foreach (BindableProperty changedResource in changedResources)
 					OnResourceChanged(changedResource, value.Value);
+
+				var bindableObject = value.Value as BindableObject;
+				if (bindableObject != null && (bindableObject as Element)?.Parent == null)
+				{
+					if (!_bindableResources.Contains(bindableObject))
+						_bindableResources.Add(bindableObject);
+					SetInheritedBindingContext(bindableObject, BindingContext);
+				}
 			}
 		}