[XamlC] compile ListStringTypeConverter (#660)

* [XamlC] compile ListStringTypeConverter

* remove debug statements

2 files changed, 42 insertions, 0 deletions

diff --git a/Xamarin.Forms.Build.Tasks/CompiledConverters/ListStringTypeConverter.cs b/Xamarin.Forms.Build.Tasks/CompiledConverters/ListStringTypeConverter.cs
new file mode 100644
index 00000000..62d7d69d
--- /dev/null
+++ b/Xamarin.Forms.Build.Tasks/CompiledConverters/ListStringTypeConverter.cs
@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+using Xamarin.Forms.Xaml;
+using Xamarin.Forms.Build.Tasks;
+
+namespace Xamarin.Forms.Core.XamlC
+{
+	class ListStringTypeConverter : ICompiledTypeConverter
+	{
+		public IEnumerable<Instruction> ConvertFromString(string value, ModuleDefinition module, BaseNode node)
+		{
+			if (value == null) {
+				yield return Instruction.Create(OpCodes.Ldnull);
+				yield break;
+			}
+			var parts = value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Trim()).ToList();
+
+			var listCtor = module.Import(typeof(List<>)).Resolve().Methods.FirstOrDefault(md => md.IsConstructor && md.Parameters.Count == 1 && md.Parameters[0].ParameterType.FullName == "System.Int32");
+			var listCtorRef = module.Import(listCtor);
+			listCtorRef = module.Import(listCtorRef.ResolveGenericParameters(module.Import(typeof(List<string>)), module));
+
+			var adder = module.Import(typeof(ICollection<>)).Resolve().Methods.FirstOrDefault(md => md.Name == "Add" && md.Parameters.Count == 1);
+			var adderRef = module.Import(adder);
+			adderRef = module.Import(adderRef.ResolveGenericParameters(module.Import(typeof(ICollection<string>)), module));
+
+			yield return Instruction.Create(OpCodes.Ldc_I4, parts.Count);
+			yield return Instruction.Create(OpCodes.Newobj, listCtorRef);
+
+			foreach (var part in parts) {
+				yield return Instruction.Create(OpCodes.Dup);
+				yield return Instruction.Create(OpCodes.Ldstr, part);
+				yield return Instruction.Create(OpCodes.Callvirt, adderRef);
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
index 6424c930..3a2929ea 100644
--- a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
+++ b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
@@ -109,6 +109,7 @@
     <Compile Include="CompiledValueProviders\ICompiledValueProvider.cs" />
     <Compile Include="CompiledValueProviders\TriggerValueProvider.cs" />
     <Compile Include="CompiledValueProviders\PassthroughValueProvider.cs" />
+    <Compile Include="CompiledConverters\ListStringTypeConverter.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <Target Name="AfterBuild">