[XamlC] compiled TypeExtension (#739)

6 files changed, 89 insertions, 85 deletions

diff --git a/Xamarin.Forms.Build.Tasks/CompiledConverters/BindablePropertyConverter.cs b/Xamarin.Forms.Build.Tasks/CompiledConverters/BindablePropertyConverter.cs
index b46d22dc..bcec1a51 100644
--- a/Xamarin.Forms.Build.Tasks/CompiledConverters/BindablePropertyConverter.cs
+++ b/Xamarin.Forms.Build.Tasks/CompiledConverters/BindablePropertyConverter.cs
@@ -52,7 +52,7 @@ namespace Xamarin.Forms.Core.XamlC
 			if (typeName == null || propertyName == null)
 				throw new XamlParseException($"Cannot convert \"{value}\" into {typeof(BindableProperty)}", node);
 
-			var typeRef = GetTypeReference(typeName, module, node);
+			var typeRef = XmlTypeExtensions.GetTypeReference(typeName, module, node);
 			if (typeRef == null)
 				throw new XamlParseException($"Can't resolve {typeName}", node);
 			bpRef = GetBindablePropertyFieldReference(typeRef, propertyName, module);
@@ -61,24 +61,6 @@ namespace Xamarin.Forms.Core.XamlC
 			return bpRef;
 		}
 
-		public static TypeReference GetTypeReference(string xmlType, ModuleDefinition module, BaseNode iNode)
-		{
-			var split = xmlType.Split(':');
-			if (split.Length > 2)
-				throw new XamlParseException($"Type \"{xmlType}\" is invalid", iNode);
-
-			string prefix, name;
-			if (split.Length == 2) {
-				prefix = split [0];
-				name = split [1];
-			} else {
-				prefix = "";
-				name = split [0];
-			}
-			var namespaceuri = iNode.NamespaceResolver.LookupNamespace(prefix) ?? "";
-			return XmlTypeExtensions.GetTypeReference(namespaceuri, name, module, iNode);
-		}
-
 		public static FieldReference GetBindablePropertyFieldReference(TypeReference typeRef, string propertyName, ModuleDefinition module)
 		{
 			TypeReference declaringTypeReference;
diff --git a/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/StaticExtension.cs b/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/StaticExtension.cs
index 4565c64f..896c03fd 100644
--- a/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/StaticExtension.cs
+++ b/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/StaticExtension.cs
@@ -26,7 +26,7 @@ namespace Xamarin.Forms.Build.Tasks
 			var typename = member.Substring(0, dotIdx);
 			var membername = member.Substring(dotIdx + 1);
 
-			var typeRef = module.ImportReference(GetTypeReference(typename, module, node));
+			var typeRef = module.ImportReference(XmlTypeExtensions.GetTypeReference(typename, module, node as BaseNode));
 			var fieldRef = GetFieldReference(typeRef, membername, module);
 			var propertyDef = GetPropertyDefinition(typeRef, membername, module);
 
@@ -79,25 +79,6 @@ namespace Xamarin.Forms.Build.Tasks
 			return new [] { Instruction.Create(OpCodes.Call, getterDef) };
 		}
 
-
-		public static TypeReference GetTypeReference(string xmlType, ModuleDefinition module, IElementNode node)
-		{
-			var split = xmlType.Split(':');
-			if (split.Length > 2)
-				throw new XamlParseException($"Type \"{xmlType}\" is invalid", node as IXmlLineInfo);
-
-			string prefix, name;
-			if (split.Length == 2) {
-				prefix = split [0];
-				name = split [1];
-			} else {
-				prefix = "";
-				name = split [0];
-			}
-			var namespaceuri = node.NamespaceResolver.LookupNamespace(prefix) ?? "";
-			return XmlTypeExtensions.GetTypeReference(new XmlType(namespaceuri, name, null), module, node as IXmlLineInfo);
-		}
-
 		public static FieldReference GetFieldReference(TypeReference typeRef, string fieldName, ModuleDefinition module)
 		{
 			TypeReference declaringTypeReference;
@@ -120,4 +101,4 @@ namespace Xamarin.Forms.Build.Tasks
 			return pDef;
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/TypeExtension.cs b/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/TypeExtension.cs
new file mode 100644
index 00000000..8d31bfc1
--- /dev/null
+++ b/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/TypeExtension.cs
@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using Xamarin.Forms.Xaml;
+using System.Xml;
+
+namespace Xamarin.Forms.Build.Tasks
+{
+	class TypeExtension : ICompiledMarkupExtension
+	{
+		public IEnumerable<Instruction> ProvideValue(IElementNode node, ModuleDefinition module, ILContext context, out TypeReference memberRef)
+		{
+			memberRef = module.ImportReference(typeof(Type));
+			INode typeNameNode;
+
+			var name = new XmlName("", "TypeName");
+			if (!node.Properties.TryGetValue(name, out typeNameNode) && node.CollectionItems.Any())
+				typeNameNode = node.CollectionItems[0];
+
+			var valueNode = typeNameNode as ValueNode;
+			if (valueNode == null)
+				throw new XamlParseException("TypeName isn't set.", node as XmlLineInfo);
+
+			if (!node.Properties.ContainsKey(name)) {
+				node.Properties[name] = typeNameNode;
+				node.CollectionItems.Clear();
+			}
+
+			var typeref = module.ImportReference(XmlTypeExtensions.GetTypeReference(valueNode.Value as string, module, node as BaseNode));
+			if (typeref == null)
+				throw new XamlParseException($"Can't resolve type `{valueNode.Value}'.", node as IXmlLineInfo);
+
+			context.TypeExtensions[node] = typeref;
+
+			var getTypeFromHandle = module.ImportReference(typeof(Type).GetMethod("GetTypeFromHandle", new[] { typeof(RuntimeTypeHandle) }));
+			return new List<Instruction> {
+				Instruction.Create(OpCodes.Ldtoken, module.ImportReference(typeref)),
+				Instruction.Create(OpCodes.Call, module.ImportReference(getTypeFromHandle))
+			};
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Build.Tasks/CreateObjectVisitor.cs b/Xamarin.Forms.Build.Tasks/CreateObjectVisitor.cs
index b73926fd..d7b05ac4 100644
--- a/Xamarin.Forms.Build.Tasks/CreateObjectVisitor.cs
+++ b/Xamarin.Forms.Build.Tasks/CreateObjectVisitor.cs
@@ -52,21 +52,28 @@ namespace Xamarin.Forms.Build.Tasks
 				return;
 			}
 
-			if (typeref.FullName == "Xamarin.Forms.Xaml.StaticExtension") {
-				var markupProvider = new StaticExtension();
+			//if this is a MarkupExtension that can be compiled directly, compile and returns the value
+			var compiledMarkupExtensionName = typeref.GetCustomAttribute(Module.ImportReference(typeof(ProvideCompiledAttribute)))?.ConstructorArguments?[0].Value as string;
+			Type compiledMarkupExtensionType;
+			ICompiledMarkupExtension markupProvider;
+			if (compiledMarkupExtensionName != null &&
+				(compiledMarkupExtensionType = Type.GetType(compiledMarkupExtensionName)) != null &&
+				(markupProvider = Activator.CreateInstance(compiledMarkupExtensionType) as ICompiledMarkupExtension) != null) {
 
 				var il = markupProvider.ProvideValue(node, Module, Context, out typeref);
 				typeref = Module.ImportReference(typeref);
 
 				var vardef = new VariableDefinition(typeref);
-				Context.Variables [node] = vardef;
+				Context.Variables[node] = vardef;
 				Context.Body.Variables.Add(vardef);
 
 				Context.IL.Append(il);
 				Context.IL.Emit(OpCodes.Stloc, vardef);
 
 				//clean the node as it has been fully exhausted
-				node.Properties.Clear();
+				foreach (var prop in node.Properties)
+					if (!node.SkipProperties.Contains(prop.Key))
+						node.SkipProperties.Add(prop.Key);
 				node.CollectionItems.Clear();
 				return;
 			}
@@ -171,47 +178,14 @@ namespace Xamarin.Forms.Build.Tasks
 					Context.IL.Emit(OpCodes.Initobj, Module.ImportReference(typedef));
 				}
 
-				if (typeref.FullName == "Xamarin.Forms.Xaml.TypeExtension") {
+				if (typeref.FullName == "Xamarin.Forms.Xaml.ArrayExtension") {
 					var visitor = new SetPropertiesVisitor(Context);
 					foreach (var cnode in node.Properties.Values.ToList())
 						cnode.Accept(visitor, node);
 					foreach (var cnode in node.CollectionItems)
 						cnode.Accept(visitor, node);
 
-					//As we're stripping the TypeExtension bare, keep the type if we need it later (hint: we do need it)
-					INode ntype;
-					if (!node.Properties.TryGetValue(new XmlName("", "TypeName"), out ntype))
-						ntype = node.CollectionItems [0];
-
-					var type = ((ValueNode)ntype).Value as string;
-					var prefix = "";
-					if (type.Contains(":")) {
-						prefix = type.Split(':') [0].Trim();
-						type = type.Split(':') [1].Trim();
-					}
-					var namespaceuri = node.NamespaceResolver.LookupNamespace(prefix);
-					Context.TypeExtensions [node] = new XmlType(namespaceuri, type, null).GetTypeReference(Module, node);
-
-					if (!node.SkipProperties.Contains(new XmlName("", "TypeName")))
-						node.SkipProperties.Add(new XmlName("", "TypeName"));
-					
-					var vardefref = new VariableDefinitionReference(vardef);
-					Context.IL.Append(SetPropertiesVisitor.ProvideValue(vardefref, Context, Module, node));
-					if (vardef != vardefref.VariableDefinition) {
-						Context.Variables [node] = vardefref.VariableDefinition;
-						Context.Body.Variables.Add(vardefref.VariableDefinition);
-					}
-				}
-
-				if (typeref.FullName == "Xamarin.Forms.Xaml.ArrayExtension")
-				{
-					var visitor = new SetPropertiesVisitor(Context);
-					foreach (var cnode in node.Properties.Values.ToList())
-						cnode.Accept(visitor, node);
-					foreach (var cnode in node.CollectionItems)
-						cnode.Accept(visitor, node);
-
-					var markupProvider = new ArrayExtension();
+					markupProvider = new ArrayExtension();
 
 					var il = markupProvider.ProvideValue(node, Module, Context, out typeref);
 
@@ -223,8 +197,12 @@ namespace Xamarin.Forms.Build.Tasks
 					Context.IL.Emit(OpCodes.Stloc, vardef);
 
 					//clean the node as it has been fully exhausted
-					node.Properties.Remove(new XmlName("","Type"));
+					foreach (var prop in node.Properties)
+						if (!node.SkipProperties.Contains(prop.Key))
+							node.SkipProperties.Add(prop.Key);
 					node.CollectionItems.Clear();
+
+					return;
 				}
 			}
 		}
diff --git a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
index c1c62eff..0175a4b8 100644
--- a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
+++ b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
@@ -110,6 +110,7 @@
     <Compile Include="CompiledValueProviders\TriggerValueProvider.cs" />
     <Compile Include="CompiledValueProviders\PassthroughValueProvider.cs" />
     <Compile Include="CompiledConverters\ListStringTypeConverter.cs" />
+    <Compile Include="CompiledMarkupExtensions\TypeExtension.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <Target Name="AfterBuild">
diff --git a/Xamarin.Forms.Build.Tasks/XmlTypeExtensions.cs b/Xamarin.Forms.Build.Tasks/XmlTypeExtensions.cs
index 59b72acc..3dd1d739 100644
--- a/Xamarin.Forms.Build.Tasks/XmlTypeExtensions.cs
+++ b/Xamarin.Forms.Build.Tasks/XmlTypeExtensions.cs
@@ -10,11 +10,6 @@ namespace Xamarin.Forms.Build.Tasks
 {
 	static class XmlTypeExtensions
 	{
- 		public static TypeReference GetTypeReference (string namespaceURI, string typename, ModuleDefinition module, IXmlLineInfo xmlInfo)
- 		{
- 			return new XmlType (namespaceURI, typename, null).GetTypeReference (module, xmlInfo);
- 		}
-
 		static IList<XmlnsDefinitionAttribute> s_xmlnsDefinitions;
 
 		static void GatherXmlnsDefinitionAttributes()
@@ -34,6 +29,29 @@ namespace Xamarin.Forms.Build.Tasks
 				}
 		}
 
+		public static TypeReference GetTypeReference(string xmlType, ModuleDefinition module, BaseNode node)
+		{
+			var split = xmlType.Split(':');
+			if (split.Length > 2)
+				throw new XamlParseException($"Type \"{xmlType}\" is invalid", node as IXmlLineInfo);
+
+			string prefix, name;
+			if (split.Length == 2) {
+				prefix = split[0];
+				name = split[1];
+			} else {
+				prefix = "";
+				name = split[0];
+			}
+			var namespaceuri = node.NamespaceResolver.LookupNamespace(prefix) ?? "";
+			return GetTypeReference(new XmlType(namespaceuri, name, null), module, node as IXmlLineInfo);
+		}
+
+		public static TypeReference GetTypeReference(string namespaceURI, string typename, ModuleDefinition module, IXmlLineInfo xmlInfo)
+		{
+			return new XmlType(namespaceURI, typename, null).GetTypeReference(module, xmlInfo);
+		}
+
 		public static TypeReference GetTypeReference(this XmlType xmlType, ModuleDefinition module, IXmlLineInfo xmlInfo)
 		{
 			if (s_xmlnsDefinitions == null)