.net native extension for node.js

Question

I want to make use of .net dlls in node.js. Does that mean I need to make those dlls available with c/c++ using 'clr hosting', a la

• .NET Framework 4 Hosting Interfaces or
• Hosting the Common Language Runtime

Unfortunately the example Creating a nodejs native .Net extension over at github was a bit of a disappointment, just scroll down to the last step

Change the "Common Language Runtime Support" option to No Common Language RunTime Support

and you know what I mean. Correction to do that article justice: It suggests to change that option to "No Common Language RunTime Support" only for the file SharpAddon.cpp, so other .cpp-files you add will have CLR support enabled (the default for a CLR project), which means you can in fact use .net dlls from those other .cpp files.

This question is actually a duplicate of Using a .NET DLL in Node.js / serverside javascript, which was written at a time when there was not even a native Windows port of node, so times might have changed, although google makes me doubt it.

Ineducation

It's hard to tell if it's being actively developed/maintained, but if you don't need 100% compatibility with node.js, this looks interesting: newcome.wordpress.com/2010/05/08/… . – Florescence

@Florescence Thanks for the link, but for the problem at hand I want to have the most stable and performing implementation possible, so I guess I'm stuck with the original, which is being developed at a really fast pace and is also getting steam on the Windows platform recently. – Ineducation

Answer 1

Update: node-gyp can do the manual steps below automatically when the binding.gyp file is setup properly. See this answer for this simplified procedure.

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It turned out to be rather easy. After struggling with CLR hosting and getting data in and out of the host for a while, it turns out you can actually enable /clr for your node extension no problem (so far). Here's how:

• follow the instructions on http://nodejs.org/api/addons.html to generate the project files
• open the generated .sln in Visual Studio (I'm on VS 2010) and enable /clr in the project settings
• now it probably won't build and you have to let the - in this case actually quite helpful - error messages guide you to the flags that conflict with /clr

The flags that I had to change to make it work:

• disable /EHsc (C++ exceptions)
• disable /RTC1 and /RTCsu
• Release: change /MT to /MD
• Debug: change /MTd to /MDd
• Release: change /GR- to /GR

Then you can mix managed and unmanaged code like this, referencing your .net dlls.

#pragma managed

#using <managed.dll>

void callManaged()
{
    managed::Class1^ c1 = gcnew managed::Class1();
    System::String^ result = c1->Echo("hola");
    System::Console::WriteLine("It works: " + result);
}

#pragma unmanaged

Handle<Value> Method(const Arguments& args) {
  HandleScope scope;
  callManaged();
  return scope.Close(String::New("world"));
}

Update Just discovered this link with an easy https://web.archive.org/web/20170702003703/http://joseoncode.com/2012/04/10/writing-your-first-native-module-for-node-dot-js-on-windows/

Ineducation

+1 nice. Now I have one more way to write native extension for node.js and enjoy power of .Net – Gumption

@Gumption It should be kept in mind though that crossing the native / CLR boundary incurs a cost every time you do it - and that depends on how often native calls into .net (or the other way around). How high that cost is, I haven't measured yet. – Ineducation

Thanks for the note. Once you run the program through the profiler, you may want to share the findings too, like on your blog – Gumption

The link is no longer active, can use "wayback machine". web.archive.org/web/20170702003703/http://joseoncode.com/2012/… – Bale

Answer 2

Sounds like edge.js is the new answer from the author of iisnode:

Edge.js supports using C# and .NET instead of writing native node.js extensions

Growl

Answer 3

These days, there's cmake-js and node-addon-api that make things both easier, plus the ABI of node-addon-api means the module does not need to be recompiled when used with a newer version of Node.js.

See this answer for a short tutorial: https://mcmap.net/q/741591/-how-to-use-mixed-c-amp-net-dll-in-node-js-error-abort-has-been-called

Ineducation