C++ listener addon example?

[kevzettler]

Hi i'm writing a node wrapper for a C level library. I'd like to structure the the Node API as a standard node event emitter something like c_lib.on("event", callback) Wondering if anyone has experience doing this and maybe an example I can eyeball. So far all i've found as far as examples are one time async callback addons like c_lib.method(callback(){}).

[Floby]

In recent versions of Node.js, the native EventEmitter class is pure Javascript. So you'll have to instanciate it from the JS constructor.

Anyway, if the library you're writing bindings to is C, you should just do the smallest work in C and do the rest in JS.

see this example from node-libspotify

https://github.com/Floby/node-libspotify/blob/master/src/player.cc

https://github.com/Floby/node-libspotify/blob/master/lib/Player.js

On Wednesday, 31 July 2013 01:22:30 UTC+2, kevzettler wrote:

Hi i'm writing a node wrapper for a C level library. I'd like to structure the the Node API as a standard node event emitter something like c_lib.on("event", callback) Wondering if anyone has experience doing this and maybe an example I can eyeball. So far all i've found as far as examples are one time async callback addons like c_lib.method(callbache k(){}).

[Gagle]

https://github.com/rvagg/node-addon-examples/issues/5

[Stephen Vickers]

The raw-socket module does something like this:

https://npmjs.org/package/raw-socket

It sub-classes from EventEmitter and emits events such as "close" and "error" from the c++ code, e.g. the close event:

https://bitbucket.org/stephenwvickers/node-raw-socket/src/7f31f7272827b7580baf989803b9662bb5de43ba/src/raw.cc?at=default#cl-421

The c++ module itself needs to inherit from EventEmitter, I found this easiest to do from within JavaScript:

https://bitbucket.org/stephenwvickers/node-raw-socket/src/7f31f7272827b7580baf989803b9662bb5de43ba/index.js?at=default#cl-62

But to make it work fully you need to do this (at least I had to do this at the time):

https://bitbucket.org/stephenwvickers/node-raw-socket/src/7f31f7272827b7580baf989803b9662bb5de43ba/index.js?at=default#cl-31

Good luck!

Steve