[Xaml[C]] supports 'using:' xmlns declarations (#851)

4 files changed, 87 insertions, 0 deletions

diff --git a/Xamarin.Forms.Xaml.UnitTests/TestXmlnsUsing.xaml b/Xamarin.Forms.Xaml.UnitTests/TestXmlnsUsing.xaml
new file mode 100644
index 00000000..f48dfdf2
--- /dev/null
+++ b/Xamarin.Forms.Xaml.UnitTests/TestXmlnsUsing.xaml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
+	xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+	xmlns:local="using:Xamarin.Forms.Xaml.UnitTests"
+	x:Class="Xamarin.Forms.Xaml.UnitTests.TestXmlnsUsing">
+	<ContentPage.Content>
+		<local:CustomXamlView />
+	</ContentPage.Content>
+</ContentPage>
diff --git a/Xamarin.Forms.Xaml.UnitTests/TestXmlnsUsing.xaml.cs b/Xamarin.Forms.Xaml.UnitTests/TestXmlnsUsing.xaml.cs
new file mode 100644
index 00000000..15eb0ff5
--- /dev/null
+++ b/Xamarin.Forms.Xaml.UnitTests/TestXmlnsUsing.xaml.cs
@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using NUnit.Framework;
+using Xamarin.Forms;
+using Xamarin.Forms.Core.UnitTests;
+
+namespace Xamarin.Forms.Xaml.UnitTests
+{
+	public partial class TestXmlnsUsing : ContentPage
+	{
+		public TestXmlnsUsing()
+		{
+			InitializeComponent();
+		}
+
+		public TestXmlnsUsing(bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+		[TestFixture]
+		class Tests
+		{
+			[SetUp]
+			public void Setup()
+			{
+				Device.PlatformServices = new MockPlatformServices();
+			}
+
+			[TearDown]
+			public void TearDown()
+			{
+				Application.Current = null;
+				Device.PlatformServices = null;
+			}
+
+			[TestCase(true)]
+			[TestCase(false)]
+			public void SupportUsingXmlns(bool useCompiledXaml)
+			{
+				var page = new TestXmlnsUsing(useCompiledXaml);
+				Assert.That(page.Content, Is.Not.Null);
+				Assert.That(page.Content, Is.TypeOf<CustomXamlView>());
+			}
+		}
+	}
+}
diff --git a/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj b/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj
index 7041001c..24d2bbde 100644
--- a/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj
+++ b/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj
@@ -461,6 +461,9 @@
     <Compile Include="Issues\Bz53203.xaml.cs">
       <DependentUpon>Bz53203.xaml</DependentUpon>
     </Compile>
+    <Compile Include="TestXmlnsUsing.xaml.cs">
+      <DependentUpon>TestXmlnsUsing.xaml</DependentUpon>
+    </Compile>
     <Compile Include="Issues\Bz54334.xaml.cs">
       <DependentUpon>Bz54334.xaml</DependentUpon>
     </Compile>
@@ -848,6 +851,9 @@
     <EmbeddedResource Include="Issues\Bz53203.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="TestXmlnsUsing.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
     <EmbeddedResource Include="Issues\Bz54334.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
diff --git a/Xamarin.Forms.Xaml/XmlnsHelper.cs b/Xamarin.Forms.Xaml/XmlnsHelper.cs
index e29dbc0c..5f7efd48 100644
--- a/Xamarin.Forms.Xaml/XmlnsHelper.cs
+++ b/Xamarin.Forms.Xaml/XmlnsHelper.cs
@@ -20,6 +20,19 @@ namespace Xamarin.Forms.Xaml
 		{
 			typeName = ns = asm = targetPlatform = null;
 
+			xmlns = xmlns.Trim();
+
+			if (xmlns.StartsWith("using:", StringComparison.Ordinal)) {
+				ParseUsing(xmlns, out typeName, out ns, out asm, out targetPlatform);
+				return;
+			}
+			ParseClrNamespace(xmlns, out typeName, out ns, out asm, out targetPlatform);
+		}
+
+		static void ParseClrNamespace(string xmlns, out string typeName, out string ns, out string asm, out string targetPlatform)
+		{
+			typeName = ns = asm = targetPlatform = null;
+
 			foreach (var decl in xmlns.Split(';'))
 			{
 				if (decl.StartsWith("clr-namespace:", StringComparison.Ordinal))
@@ -46,5 +59,17 @@ namespace Xamarin.Forms.Xaml
 					typeName = decl;
 			}
 		}
+
+		static void ParseUsing(string xmlns, out string typeName, out string ns, out string asm, out string targetPlatform)
+		{
+			typeName = ns = asm = targetPlatform = null;
+
+			foreach (var decl in xmlns.Split(';')) {
+				if (decl.StartsWith("using:", StringComparison.Ordinal)) {
+					ns = decl.Substring(6, decl.Length - 6);
+					continue;
+				}
+			}
+		}
 	}
 }
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