Using a .NET DLL in Node.js / serverside javascript

Question

I have a pet project that is an online game, the entire game engine is written in C# and I would like to know if there is anyway I can call the functions of this existing as

Answer 1

If all you want to do is spin up a lightweight HTTP server while still programming with C# and .Net you should give Kayak a chance. It is a lightweight HTTP Server for C# and behaves kind of like node.js in that sense.

kayakhttp

Update:

If you are looking for a lightweight HTTP Server to handle web requests you have a couple alternatives today:

• ServiceStack (recommended)
• Microsoft WebAPI
• NancyFx

To my knowledge all the above work on some version of Mono, so you can still host them across both Windows and Unix based systems.

Answer 2

I know it's an old question, but wanted to throw in a current answer. With IIS 7.5 and .Net 4.x Websockets are supported, though use of the SignalR library will likely be the path of least resistance. It's similar to the socket.io library for NodeJS.

As to accessing .Net code via NodeJS, your best options are Edge.js, building a mixed native assembly with C/C++, exposing your .Net code either via a command line application (best to use pipes for input/output) or via a service (TCP or other).

I find Edge.js to be very limited, and not offer much over a piped console interface.. and feel that a service may be best for a more complex interface. At which point you may be best doing the rest of the project in .Net, unless you have an investment in NodeJS that supersedes said difficulties.

Answer 3

Check out the edge.js project I started (http://tjanczuk.github.com/edge). It provides a mechanism for running .NET and node.js code in-process. Edge.js allows you to call .NET code from node.js and node.js code from .NET. It marshals data between .NET and node.js as well as reconciles the threading models between multi-threaded CLR and single threaded V8.

Using edge.js you can access islands of pre-existing .NET code from node.js, which seems to match your scenario.

Answer 4

You might have some luck with this project, which is a port of Node.js to .NET. I haven't used it myself, but with a native .NET implementation you theoretically should be able to do what you need to.

You might also want to go the other direction and try to port (aka: recompile unless you're hooked deep into Windows) your C# game engine to Mono and see if you can then build wrappers off of that.

Answer 5

I've been recently faced with the same challenge (requirement to call C# code from node.js javascript). I had 1000s of lines of complex C# code that I really didn't like to port to javascript.

I solved if as follows.

• The relevant C# code is basically 1-2 classes in a DLL assembly
• Defined a COM interface which is a subset of the C# class's interface and implemented that interface in the C# class. Thus, the DLL became an in-process COM server.
• Implemented a node.js extension DLL that instantiates my C# COM class using standard Win32 COM API and routes method calls from node.js javascript to C# code using the COM interface.

This solves the problem if one only wants to make calls in one direction. I also had the requirement to make calls from C# to javascript. This is a lot harder. One has to:

• Implement a COM object in the node.js extension DLL (ATL helps here)
• Pass an interface reference of this COM object to C# code (COM Interop)
• Route calls via the COM object to V8 objects in node.js

Maybe if I have some extra time, I might make an example project out of this.

Answer 6

.Net addons can be written, in short you write a regular native addon and add .Net calls via CLI/C++ calls to .Net dlls.

In practice you usually create a C# dll library which you then call from a CLI/C++ node addon project. There is a bit of delicacies such as making sure that the actual node add on definition file is compiled without CLR support so node can load it correctly.

You can check out: https://github.com/saary/node.net for an example of how this can be achieved.