C#•15mo ago•

39 replies

Dynamically Implementing Interfaces at Runtime

Good day all,

For a modding framework refactor/rework, we are implementing interface-based events, which can be defined by mods and will be loaded at runtime as well, ie:

public interface IEventUpdate : IEvent
{
    void Update(float deltaTime);
}

// Subcription is automatic for implementing types
public class SomeUpdateableModClass : IEventUpdate 
{
    void Update(float deltaTime) { /* do something */}
}

public interface IEventUpdate : IEvent
{
    void Update(float deltaTime);
}

// Subcription is automatic for implementing types
public class SomeUpdateableModClass : IEventUpdate 
{
    void Update(float deltaTime) { /* do something */}
}

and an event publisher will follow a pattern as follows:

public class SomeModClass
{
    private readonly EventService _eventService;
    public SomeModClass(EventService eventService){ /* DI Injection */ }

    void Pushupdate()
    {
        _eventService.PublishEvent<IEventUpdate>((subscriber) => subscriber.Update(20));
    }
}

public class SomeModClass
{
    private readonly EventService _eventService;
    public SomeModClass(EventService eventService){ /* DI Injection */ }

    void Pushupdate()
    {
        _eventService.PublishEvent<IEventUpdate>((subscriber) => subscriber.Update(20));
    }
}

The issue we have is that we support

Lua

Lua

scripting via

MoonSharp

MoonSharp

, which includes events. This was here before and we have the legacy API which must be supported as follows:

EventService.Add("IEventUpdate", "someIndentifierString", function(deltaTime)
    -- do something
end)

EventService.Add("IEventUpdate", "someIndentifierString", function(deltaTime)
    -- do something
end)

So, I've been investigating using some combination of

Linq.Expression

Linq.Expression

and

ExpandoObject

ExpandoObject

dynamic

dynamic

to dynamically construct a runtime proxy type that implements the interface but searching has been kind of a pain because all major examples are for either

.NET Framework

.NET Framework

and don't work in .NET Core, or they're for Mocking/Testing and are answered using

Moq

Moq

Castle

Castle

or some other testing-targeted framework.

I'd like to avoid having to

Emit

Emit

an IL method dynamically. We have some of this already for dynamic hooking classes and maintain it has been a growing pain.

What are my options here? Because this is my goal in pseudo code:

public delegate void LuaCsAction(params object[] args);

public class EventService : IEventService
{
    // ... assume there're collections up here
    public void Add(string eventId, string identifier, params LuaCsAction[] args)
    {
        var obj = new ExpandoObject();
        var mArr = _eventTypes[eventId].GetMethods();
        for(int i=0; i<mArr.Length; i++)
        {
            ((IDictionary<string, object>)obj)[mArr[i].Name] = args[i];
        }

        _eventSubscribers[_eventTypes[eventId]][identifier] = obj; //yes, I'm ommitting the cast.
    }
}

public delegate void LuaCsAction(params object[] args);

public class EventService : IEventService
{
    // ... assume there're collections up here
    public void Add(string eventId, string identifier, params LuaCsAction[] args)
    {
        var obj = new ExpandoObject();
        var mArr = _eventTypes[eventId].GetMethods();
        for(int i=0; i<mArr.Length; i++)
        {
            ((IDictionary<string, object>)obj)[mArr[i].Name] = args[i];
        }

        _eventSubscribers[_eventTypes[eventId]][identifier] = obj; //yes, I'm ommitting the cast.
    }
}

Anyways, any help is appreciated.

Dynamically Implementing Interfaces at Runtime

Good day all,

For a modding framework refactor/rework, we are implementing interface-based events, which can be defined by mods and will be loaded at runtime as well, ie:

public interface IEventUpdate : IEvent
{
    void Update(float deltaTime);
}

// Subcription is automatic for implementing types
public class SomeUpdateableModClass : IEventUpdate 
{
    void Update(float deltaTime) { /* do something */}
}

public interface IEventUpdate : IEvent
{
    void Update(float deltaTime);
}

// Subcription is automatic for implementing types
public class SomeUpdateableModClass : IEventUpdate 
{
    void Update(float deltaTime) { /* do something */}
}

and an event publisher will follow a pattern as follows:

public class SomeModClass
{
    private readonly EventService _eventService;
    public SomeModClass(EventService eventService){ /* DI Injection */ }

    void Pushupdate()
    {
        _eventService.PublishEvent<IEventUpdate>((subscriber) => subscriber.Update(20));
    }
}

public class SomeModClass
{
    private readonly EventService _eventService;
    public SomeModClass(EventService eventService){ /* DI Injection */ }

    void Pushupdate()
    {
        _eventService.PublishEvent<IEventUpdate>((subscriber) => subscriber.Update(20));
    }
}

The issue we have is that we support

Lua

Lua

scripting via

MoonSharp

MoonSharp

, which includes events. This was here before and we have the legacy API which must be supported as follows:

EventService.Add("IEventUpdate", "someIndentifierString", function(deltaTime)
    -- do something
end)

EventService.Add("IEventUpdate", "someIndentifierString", function(deltaTime)
    -- do something
end)

So, I've been investigating using some combination of

Linq.Expression

Linq.Expression

and

ExpandoObject

ExpandoObject

dynamic

dynamic

to dynamically construct a runtime proxy type that implements the interface but searching has been kind of a pain because all major examples are for either

.NET Framework

.NET Framework

and don't work in .NET Core, or they're for Mocking/Testing and are answered using

Moq

Moq

Castle

Castle

or some other testing-targeted framework.

I'd like to avoid having to

Emit

Emit

an IL method dynamically. We have some of this already for dynamic hooking classes and maintain it has been a growing pain.

What are my options here? Because this is my goal in pseudo code:

public delegate void LuaCsAction(params object[] args);

public class EventService : IEventService
{
    // ... assume there're collections up here
    public void Add(string eventId, string identifier, params LuaCsAction[] args)
    {
        var obj = new ExpandoObject();
        var mArr = _eventTypes[eventId].GetMethods();
        for(int i=0; i<mArr.Length; i++)
        {
            ((IDictionary<string, object>)obj)[mArr[i].Name] = args[i];
        }

        _eventSubscribers[_eventTypes[eventId]][identifier] = obj; //yes, I'm ommitting the cast.
    }
}

public delegate void LuaCsAction(params object[] args);

public class EventService : IEventService
{
    // ... assume there're collections up here
    public void Add(string eventId, string identifier, params LuaCsAction[] args)
    {
        var obj = new ExpandoObject();
        var mArr = _eventTypes[eventId].GetMethods();
        for(int i=0; i<mArr.Length; i++)
        {
            ((IDictionary<string, object>)obj)[mArr[i].Name] = args[i];
        }

        _eventSubscribers[_eventTypes[eventId]][identifier] = obj; //yes, I'm ommitting the cast.
    }
}

Anyways, any help is appreciated.

Dynamically Implementing Interfaces at Runtime

Dynamically Implementing Interfaces at Runtime

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