public EventInvokerMethod AddOnPropertyChangingMethod(TypeDefinition targetType)
{
var propertyChangingField = FindPropertyChangingField(targetType);
if (propertyChangingField == null)
{
return(null);
}
if (FoundInterceptor)
{
if (targetType.HasGenericParameters)
{
var message = string.Format("Error processing '{0}'. Interception is not supported on generic types. To manually work around this problem add a [DoNotNotify] to the class and then manually implement INotifyPropertyChanging for that class and all child classes. If you would like this feature handled automatically please feel free to submit a pull request.", targetType.Name);
throw new WeavingException(message);
}
var methodDefinition = GetMethodDefinition(targetType, propertyChangingField);
return(new EventInvokerMethod
{
MethodReference = InjectInterceptedMethod(targetType, methodDefinition).GetGeneric(),
IsVisibleFromChildren = true,
InvokerType = InterceptorType,
});
}
return(new EventInvokerMethod
{
MethodReference = InjectMethod(targetType, EventInvokerNames.First(), propertyChangingField).GetGeneric(),
IsVisibleFromChildren = true,
InvokerType = InterceptorType,
});
}
MethodDefinition GetMethodDefinition(TypeDefinition targetType, FieldReference propertyChangedField)
{
var eventInvokerName = "Inner" + EventInvokerNames.First();
var methodDefinition = targetType.Methods.FirstOrDefault(x => x.Name == eventInvokerName);
if (methodDefinition?.Parameters.Count == 1 && methodDefinition.Parameters[0].ParameterType.FullName == "System.String")
{
return(methodDefinition);
}
return(InjectMethod(targetType, eventInvokerName, propertyChangedField));
}
MethodDefinition GetMethodDefinition(TypeDefinition targetType)
{
var eventInvokerName = $"Inner{EventInvokerNames.First()}";
var methodDefinition = targetType.Methods.FirstOrDefault(x => x.Name == eventInvokerName);
if (methodDefinition?.Parameters.Count == 1 && methodDefinition.Parameters[0].ParameterType.FullName == "System.String")
{
return(methodDefinition);
}
return(InjectMethod(targetType, eventInvokerName));
}
MethodDefinition InjectInterceptedMethod(TypeDefinition targetType, MethodDefinition innerOnPropertyChanging)
{
var delegateHolderInjector = new DelegateHolderInjector
{
TargetTypeDefinition = targetType,
OnPropertyChangingMethodReference = innerOnPropertyChanging,
ModuleWeaver = this
};
delegateHolderInjector.InjectDelegateHolder();
var method = new MethodDefinition(EventInvokerNames.First(), GetMethodAttributes(targetType), ModuleDefinition.TypeSystem.Void);
var propertyName = new ParameterDefinition("propertyName", ParameterAttributes.None, ModuleDefinition.TypeSystem.String);
method.Parameters.Add(propertyName);
if (InterceptorType == InvokerTypes.Before)
{
var before = new ParameterDefinition("before", ParameterAttributes.None, ModuleDefinition.TypeSystem.Object);
method.Parameters.Add(before);
}
var action = new VariableDefinition("firePropertyChanging", ActionTypeReference);
method.Body.Variables.Add(action);
var variableDefinition = new VariableDefinition("delegateHolder", delegateHolderInjector.TypeDefinition);
method.Body.Variables.Add(variableDefinition);
var instructions = method.Body.Instructions;
var last = Instruction.Create(OpCodes.Ret);
instructions.Add(Instruction.Create(OpCodes.Newobj, delegateHolderInjector.ConstructorDefinition));
instructions.Add(Instruction.Create(OpCodes.Stloc_1));
instructions.Add(Instruction.Create(OpCodes.Ldloc_1));
instructions.Add(Instruction.Create(OpCodes.Ldarg_1));
instructions.Add(Instruction.Create(OpCodes.Stfld, delegateHolderInjector.PropertyName));
instructions.Add(Instruction.Create(OpCodes.Ldloc_1));
instructions.Add(Instruction.Create(OpCodes.Ldarg_0));
instructions.Add(Instruction.Create(OpCodes.Stfld, delegateHolderInjector.Target));
instructions.Add(Instruction.Create(OpCodes.Ldloc_1));
instructions.Add(Instruction.Create(OpCodes.Ldftn, delegateHolderInjector.MethodDefinition));
instructions.Add(Instruction.Create(OpCodes.Newobj, ActionConstructorReference));
instructions.Add(Instruction.Create(OpCodes.Stloc_0));
instructions.Add(Instruction.Create(OpCodes.Ldarg_0));
instructions.Add(Instruction.Create(OpCodes.Ldloc_0));
instructions.Add(Instruction.Create(OpCodes.Ldloc_1));
instructions.Add(Instruction.Create(OpCodes.Ldfld, delegateHolderInjector.PropertyName));
if (InterceptorType == InvokerTypes.Before)
{
instructions.Add(Instruction.Create(OpCodes.Ldarg_2));
instructions.Add(Instruction.Create(OpCodes.Call, InterceptMethod));
}
else
{
instructions.Add(Instruction.Create(OpCodes.Call, InterceptMethod));
}
instructions.Add(last);
method.Body.InitLocals = true;
targetType.Methods.Add(method);
return(method);
}