extracting world-specific data from Game

OpenRA.Game/ObjectCreator.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using OpenRA.FileFormats;
+using System.Reflection;
+using System.IO;
+
+namespace OpenRA
+{
+	public class ObjectCreator
+	{
+		Pair<Assembly, string>[] ModAssemblies;
+
+		public ObjectCreator( Manifest manifest )
+		{
+			// All the core namespaces
+			var asms = typeof(Game).Assembly.GetNamespaces()
+				.Select(c => Pair.New(typeof(Game).Assembly, c))
+				.ToList();
+
+			// Namespaces from each mod assembly
+			foreach (var a in manifest.Assemblies)
+			{
+				var asm = Assembly.LoadFile(Path.GetFullPath(a));
+				asms.AddRange(asm.GetNamespaces().Select(ns => Pair.New(asm, ns)));
+			}
+
+			ModAssemblies = asms.ToArray();
+		}
+
+		public static Action<string> MissingTypeAction = 
+			s => { throw new InvalidOperationException("Cannot locate type: {0}".F(s)); };
+
+		public T CreateObject<T>(string classname)
+		{
+			foreach (var mod in ModAssemblies)
+			{
+				var fullTypeName = mod.Second + "." + classname;
+				var obj = mod.First.CreateInstance(fullTypeName);
+				if (obj != null)
+					return (T)obj;
+			}
+
+			MissingTypeAction(classname);
+			return default(T);
+		}
+
+	}
+}