private static void DefineGuardedProperty(PropertyInfo property, TypeBuilder typeBuilder, FieldInfo field, Type objectType, IEntityMap entityMap)
{
// create the new property.
var propertyBuilder = typeBuilder.DefineProperty(property.Name, System.Reflection.PropertyAttributes.HasDefault, property.PropertyType, null);
// The property "set" and property "get" methods require a special set of attributes.
//var getSetAttr = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig | MethodAttributes.Virtual;
var getSetAttr = MethodAttributes.Private | MethodAttributes.HideBySig | MethodAttributes.NewSlot | MethodAttributes.Virtual | MethodAttributes.Final | MethodAttributes.SpecialName;
// create the getter if we can read.
if (property.CanRead)
{
// create the get method for the property.
var getMethodName = "get_" + property.Name;
var getMethod = typeBuilder.DefineMethod(getMethodName, getSetAttr, property.PropertyType, Type.EmptyTypes);
// get the IL generator to generate the required IL.
ILGenerator il = getMethod.GetILGenerator();
// directly call the inner object's get method of the property.
if (Reflector.IsDataEntityList(property.PropertyType, out var elementType))
{
var isInterface = property.PropertyType.GetGenericTypeDefinition() == typeof(IList <>);
var asReadOnlyMethod = typeof(ObjectExtensions).GetMethods(BindingFlags.Public | BindingFlags.Static).Where(m => m.Name == "AsReadOnly").First(m => m.GetParameters()[0].ParameterType.Name == (isInterface ? "IList`1" : "List`1"));
var result = il.DeclareLocal(property.PropertyType);
// load the first argument (the instance itself) and the field.
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, field);
il.EmitCall(OpCodes.Callvirt, property.GetGetMethod(), null);
il.Emit(OpCodes.Call, asReadOnlyMethod.MakeGenericMethod(elementType));
il.Emit(OpCodes.Stloc_0, result);
il.Emit(OpCodes.Ldloc_0);
}
else if (Reflector.IsDataEntity(property.PropertyType))
{
var asReadOnlyMethod = typeof(ObjectExtensions).GetMethods(BindingFlags.Public | BindingFlags.Static).Where(m => m.Name == "AsReadOnly").First(m => m.GetParameters()[0].ParameterType.IsGenericParameter);
var result = il.DeclareLocal(property.PropertyType);
// load the first argument (the instance itself) and the field.
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, field);
il.EmitCall(OpCodes.Callvirt, property.GetGetMethod(), null);
il.Emit(OpCodes.Call, asReadOnlyMethod.MakeGenericMethod(property.PropertyType));
il.Emit(OpCodes.Stloc_0, result);
il.Emit(OpCodes.Ldloc_0);
}
else if (property.DeclaringType.InheritsFrom(typeof(ITrackableDataEntity)) && property.PropertyType == typeof(ObjectState) && property.Name == "ObjectState")
{
il.Emit(OpCodes.Ldc_I4, (int)ObjectState.ReadOnly);
}
else
{
// load the first argument (the instance itself) and the field.
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, field);
il.EmitCall(OpCodes.Callvirt, property.GetGetMethod(), null);
}
il.Emit(OpCodes.Ret);
// set the method.
propertyBuilder.SetGetMethod(getMethod);
typeBuilder.DefineMethodOverride(getMethod, property.ReflectedType.GetMethod(getMethodName));
}
// create the setter if we can read.
if (property.CanWrite)
{
// create the set method of the property.
var setMethodName = "set_" + property.Name;
var setMethod = typeBuilder.DefineMethod(setMethodName, getSetAttr, null, new Type[] { property.PropertyType });
// get the IL generator to generate some IL.
ILGenerator il = setMethod.GetILGenerator();
// load the first argument (instance itself) and the field.
il.Emit(OpCodes.Newobj, typeof(NotSupportedException).GetConstructor(Type.EmptyTypes));
il.Emit(OpCodes.Throw);
propertyBuilder.SetSetMethod(setMethod);
typeBuilder.DefineMethodOverride(setMethod, property.ReflectedType.GetMethod(setMethodName));
}
}
