public FactoryClass(IConstructorArgList argList, IList<IFactoryMethod> methods)
{
m_argList = argList;
Methods = methods;
foreach (var definition in methods.SelectMany(m => m.ConstructorArgs))
argList.Add(definition);
}
public void EmitMethod(TypeBuilder tb, IConstructorArgList constructorArgList)
{
var methodAttributes = MethodAttributes.Public |
MethodAttributes.HideBySig |
MethodAttributes.NewSlot |
MethodAttributes.Virtual |
MethodAttributes.Final;
var method = tb.DefineMethod(
Name,
methodAttributes,
CallingConventions.Standard,
ReturnType,
ConstructorArgs.OfType<IPassedConstructorArgDefinition>().Select(a => a.ParameterType).ToArray());
var consArgTypes = ConstructorArgs.Select(a => a.ParameterType).ToArray();
var conObj = ReturnImplType.GetConstructor(consArgTypes);
if (conObj == null)
throw new Exception("Failed to find constructor of type " + ReturnImplType.FullName + " with arguments: " + string.Join(", ", consArgTypes.Select(a => a.FullName)));
ILGenerator il = method.GetILGenerator();
il.DeclareLocal(ReturnImplType);
il.Emit(OpCodes.Nop);
foreach (var arg in ConstructorArgs)
{
if (arg is IInjectableConstructorArgDefinition)
{
var passedArgument = constructorArgList.FindExisting(arg);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Call, ((IInjectableConstructorArg)passedArgument).Getter);
}
else if (arg is IPassedConstructorArgDefinition)
{
il.Emit(OpCodes.Ldarg, ((IPassedConstructorArgDefinition)arg).ParameterIndex + 1);
}
else
{
throw new Exception("Unrecognised type of argument: " + arg.GetType().FullName);
}
}
il.Emit(OpCodes.Newobj, conObj);
il.Emit(OpCodes.Nop);
il.Emit(OpCodes.Ret);
}
