I've done it. The solution is to use EdgeJS as a bridge between NodeJS V8 and C# CLR. Edge loads the DLL and creates a communication channel between V8 and CLR, the messages are functions of the form Func<object, Task<object>> or function(payload, callback) that are marshalled between each language VM.
I'll post the code sample below:
C#
public abstract class NetWebSocket
{
private Func<object, Task<object>> SendImpl { get; set; }
protected NetWebSocket(Func<object, Task<object>> sendImpl)
{
this.SendImpl = sendImpl;
}
protected abstract Task ReceiveAsync(string message);
public Func<object, Task<object>> ReceiveImpl
{
get
{
return async (input) =>
{
Console.Out.WriteLine(input);
await this.ReceiveAsync((string) input);
return Task.FromResult<object>(null);
};
}
}
protected async Task SendAsync(string message)
{
await this.SendImpl(message);
return;
}
}
public class MyNetWebSocketImpl : NetWebSocket
{
public CHello module;
private string JSONCodelineDataRepr = "not set";
public MyNetWebSocketImpl(Func<object, Task<object>> sendImpl) : base(sendImpl)
{
// do other stuff after calling the super class constructor
module = new CHello();
module.DocumentReadEvent += this.DocumentReadEventHandler;
module.DocumentReadErrorEvent += this.DocumentReadErrorEventHandler;
// uncomment after the websocket communication works
module.Start();
}
protected override async Task ReceiveAsync(string message)
{
// not really needed because only the NodeJS Server listens to C# .NET Server messages
Console.WriteLine(message);
if (message.Equals("shutdown"))
{
module.Close();
}
// not necessary (can comment the send function call)
// if I eventually receive a message, respond with the JSON representation of the Patient ID Card
await this.SendAsync("I received a message from you, but I'll ignore it and send you the Patient" +
" ID Card Data instead.. I'm a fish, so start phishing! PersonData = " +
JSONCodelineDataRepr);
return;
}
private async void DocumentReadEventHandler(string args)
{
this.JSONCodelineDataRepr = args;
await this.SendAsync(args);
}
private async void DocumentReadErrorEventHandler(string args)
{
await this.SendAsync(args);
}
}
public class Startup
{
public static MyNetWebSocketImpl ws;
public async Task<object> Invoke(Func<object, Task<object>> sendImpl)
{
ws = new MyNetWebSocketImpl(sendImpl);
return ws.ReceiveImpl;
}
}
Javascript/NodeJS
(function(e,d,g,e){
var edge = require('edge'),
http = require('http'),
WebSocketServer = require('ws').Server,
swipe = edge.func('./dlls/ActiveXCOM.dll');
var server = http.createServer(function(req,res){
res.writeHead(200, {'Content-Type' : 'text/html'});
res.end((
function () { /*
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<div id='jsonOutput'>
</div>
<script>
var ws = new WebSocket('ws://' + window.document.location.host);
ws.onmessage = function (event) {
console.log(event.data);
var div = document.getElementById('jsonOutput');
div.innerHTML = event.data;
}
ws.onopen = function (event) {
// send something to the server
ws.send('I am the client from the browser calling you, the NodeJS WebSocketServer!');
}
ws.onclose = function (event) {
alert('websocket closing');
}
window.onbeforeunload = function myonbeforeUnload() {
return "Are you sure?";
}
window.onunload = function myonunload() {
confirm('Are you really sure?');
ws.close();
return "Are you really sure?";
}
</script>
</body>
</html>
*/}).toString().match(/[^]*\/\*([^]*)\*\/\}$/)[1]);
});
var wss = new WebSocketServer({server: server});
wss.on('connection', function(ws) {
var sendImpl = function (message, callback) {
console.log(message);
ws.send(message);
callback();
};
var receiveHandler = swipe(sendImpl, true);
ws.on('message', function (message) {
receiveHandler(message);
});
ws.on('close', function close(){
console.log('****************************The client disconnected!');
receiveHandler('shutdown');
delete receiveHandler;
});
});
server.listen(process.env.PORT || 8080);
module.exports = this;
})();
I hope the implementation is clear. If you have any trouble understanding it, please don't hesitate to write to me.
Happy Coding!
[Don't listen to the naysayers!]
