将网络套接字变成可观察的答案

【问题标题】：Turn a net socket into an observable将网络套接字变成可观察的
【发布时间】：2017-03-12 17:59:29
【问题描述】：

我有一个 net tcp 套接字 node.js 部分代码，我想将其从使用 callback 转换为 rx。

我在feed.js 模块中看起来像这样：

var net = require('net');
var server = net.createServer(function(socket) {
...

    // Handle incoming messages from clients.
    socket.on('data', function (data) {
        broadcast(data, socket);
    });

...
}

function broadcast(message, sender)
{  
   ...
   onChangeHandler(stock.symbol, 'stock', stock);
}
}

function start(onChange) {
    onChangeHandler = onChange;
}

exports.start = start;
server.listen(....);

然后上面调用的客户端注册一个回调：

feed.start(function(room, type, message) {
   //...Do something with the message
});

我想将其转换为使用 Rx Observable/Observer。我看到有一种方法可以从web socket 创建一个可观察的流（尽管它使用我不需要的双向Subject）：

fromWebSocket(address, protocol) {
    var ws = new WebSocket(address, protocol);

    // Handle the data
    var osbervable = Rx.Observable.create (function (obs) {
        // Handle messages  
        ws.onmessage = obs.onNext.bind(obs);
        ws.onerror = obs.onError.bind(obs);
        ws.onclose = obs.onCompleted.bind(obs);

        // Return way to unsubscribe
        return ws.close.bind(ws);
    });

    var observer = Rx.Observer.create(function (data) {
        if (ws.readyState === WebSocket.OPEN) { ws.send(data); }
    });

    return Rx.Subject.create(observer, observable);
}

var socketSubject = fromWebSocket('ws://localhost:9999', 'sampleProtocol');

// Receive data
socketSubject.subscribe(
    function (data) {
        // Do something with the data
    },
    function (error) {
        // Do something with the error
    },
    function () {
        // Do something on completion
    });

// Send data
socketSubject.onNext(42);

net 套接字的等价物是什么？如果有标准库可以使用。

我最初的尝试是这样，但我不知道如何将Rx 和套接字函数绑定到onnext：

var net = require('net');

fromNetSocket(address, protocol) {
    var ns = net.createServer(function(socket) {


        socket.on('disconnect', function () { // This seems like it maps to onclose

            console.log('User disconnected. %s. Socket id %s', socket.id);
        });

        // Handle incoming messages from clients.
        socket.on('data', function (data) { //this should map to onnext

        });

        // Handle the data
        var osbervable = Rx.Observable.create (function (obs) {
            // Handle messages  
            ns.onmessage = obs.onNext.bind(obs);
            ns.onerror = obs.onError.bind(obs);
            ns.onclose = obs.onCompleted.bind(obs);

            // Return way to unsubscribe
            return ns.close.bind(ns);
        });        
    });
};

【问题讨论】：

标签： node.js rxjs

【解决方案1】：

试试下面的

const createSubject = () => {

  return Rx.Observable.create((observer) => {

    const socket = net.connect({port: 1705}, () => {

      log.i('Connected to Server!');

      let socketObservable = Rx.Observable.create((observer) => {
        socket.on('data', (data) => observer.next(JSON.parse(data)));
        socket.on('error', (err) => observer.error(err));
        socket.on('close', () => observer.complete());
      });

      let socketObserver = {
        next: (data) => {
          if (!socket.destroyed) {
            socket.write(`${JSON.stringify(data)}\r\n`);
          }
        }
      };

      const subject = Rx.Subject.create(socketObserver, socketObservable);
      observer.next(subject);
      observer.complete();

    });

  });

};

那你就可以这样用主语了

createSubject().subscribe((con) => {

  con.subscribe((data) => console.log(data));

  con.next({
    id: utils.UUID(),
    jsonrpc: '2.0',
    method: 'Server.GetRPCVersion'
  });

});

【讨论】：