Re-emit 'start', 'forward' and 'end' events in RoutingProxy

README.md

@@ -217,6 +217,32 @@ proxyServerWithForwarding.listen(80);
 
 The forwarding option can be used in conjunction with the proxy table options by simply including both the 'forward' and 'router' properties in the options passed to 'createServer'.
 
+### Listening for proxy events
+Sometimes you want to listen to an event on a proxy. For example, you may want to listen to the 'end' event, which represents when the proxy has finished proxying a request.
+
+``` js
+var httpProxy = require('http-proxy');
+
+var server = httpProxy.createServer(function (req, res, proxy) {
+
+    var buffer = httpProxy.buffer(req);
+
+    proxy.proxyRequest(req, res, {
+      host: '127.0.0.1',
+      port: 9000,
+      buffer: buffer
+    });
+
+});
+
+server.proxy.on('end', function() {
+  console.log("The request was proxied.");
+});
+
+server.listen(8000);
+```
+
+It's important to remember not to listen for events on the proxy object in the function passed to `httpProxy.createServer`. Doing so would add a new listener on every request, which would end up being a disaster.
 
 ## Using HTTPS
 You have all the full flexibility of node-http-proxy offers in HTTPS as well as HTTP. The two basic scenarios are: with a stand-alone proxy server or in conjunction with another HTTPS server.

lib/node-http-proxy/routing-proxy.js

@@ -23,26 +23,26 @@ var RoutingProxy = exports.RoutingProxy = function (options) {
 
   var self = this;
   options = options || {};
-  
+
   if (options.router) {
     this.proxyTable = new ProxyTable(options);
     this.proxyTable.on('routes', function (routes) {
       self.emit('routes', routes);
     });
   }
-  
+
   //
-  // Create a set of `HttpProxy` objects to be used later on calls 
+  // Create a set of `HttpProxy` objects to be used later on calls
   // to `.proxyRequest()` and `.proxyWebSocketRequest()`.
   //
   this.proxies = {};
-  
+
   //
   // Setup default target options (such as `https`).
   //
   this.target       = {};
   this.target.https = options.target && options.target.https;
-  
+
   //
   // Setup other default options to be used for instances of
   // `HttpProxy` created by this `RoutingProxy` instance.
@@ -51,6 +51,18 @@ var RoutingProxy = exports.RoutingProxy = function (options) {
   this.https   = this.source.https    || options.https;
   this.enable  = options.enable;
   this.forward = options.forward;
+
+  //
+  // Listen for 'newListener' events so that we can bind 'proxyError'
+  // listeners to each HttpProxy's 'proxyError' event.
+  //
+  this.on('newListener', function (evt) {
+    if (evt === 'proxyError' || evt === 'webSocketProxyError') {
+      Object.keys(self.proxies).forEach(function (key) {
+        self.proxies[key].on(evt, this.emit.bind(this, evt));
+      });
+    }
+  });
 };
 
 
@@ -68,30 +80,37 @@ util.inherits(RoutingProxy, events.EventEmitter);
 RoutingProxy.prototype.add = function (options) {
   var self = this,
       key = this._getKey(options);
-  
+
   //
   // TODO: Consume properties in `options` related to the `ProxyTable`.
   //
   options.target       = options.target       || {};
   options.target.host  = options.target.host  || options.host;
   options.target.port  = options.target.port  || options.port;
-  options.target.https = this.target && this.target.https || 
-                         options.target && options.target.https || 
+  options.target.https = this.target && this.target.https ||
+                         options.target && options.target.https ||
                          options.https;
-  
+
   //
   // Setup options to pass-thru to the new `HttpProxy` instance
-  // for the specified `options.host` and `options.port` pair. 
+  // for the specified `options.host` and `options.port` pair.
   //
   ['https', 'enable', 'forward'].forEach(function (key) {
     if (options[key] !== false && self[key]) {
       options[key] = self[key];
     }
   });
-  
+
   this.proxies[key] = new HttpProxy(options);
-  this.proxies[key].on('proxyError', this.emit.bind(this, 'proxyError'));
-  this.proxies[key].on('webSocketProxyError', this.emit.bind(this, 'webSocketProxyError'));
+  if (this.listeners('proxyError').length > 0) {
+    this.proxies[key].on('proxyError', this.emit.bind(this, 'proxyError'));
+  }
+  if (this.listeners('webSocketProxyError').length > 0) {
+    this.proxies[key].on('webSocketProxyError', this.emit.bind(this, 'webSocketProxyError'));
+  }
+  this.proxies[key].on('start', this.emit.bind(this, 'start'));
+  this.proxies[key].on('forward', this.emit.bind(this, 'forward'));
+  this.proxies[key].on('end', this.emit.bind(this, 'end'));
 };
 
 //
@@ -111,18 +130,18 @@ RoutingProxy.prototype.remove = function (options) {
 //
 RoutingProxy.prototype.close = function () {
   var self = this;
-  
+
   if (this.proxyTable) {
     //
-    // Close the `RoutingTable` associated with 
+    // Close the `RoutingTable` associated with
     // this instance (if any).
     //
     this.proxyTable.close();
   }
-  
+
   //
   // Close all sockets for all `HttpProxy` object(s)
-  // associated with this instance. 
+  // associated with this instance.
   //
   Object.keys(this.proxies).forEach(function (key) {
     self.proxies[key].close();
@@ -160,11 +179,11 @@ RoutingProxy.prototype.proxyRequest = function (req, res, options) {
       try {
         res.writeHead(404);
         res.end();
-      } 
+      }
       catch (er) {
         console.error("res.writeHead/res.end error: %s", er.message);
       }
-      
+
       return;
     }
 
@@ -179,15 +198,14 @@ RoutingProxy.prototype.proxyRequest = function (req, res, options) {
     options.port = location.port;
     options.host = location.host;
   }
-  
+
   var key = this._getKey(options),
     proxy;
-  
+
   if (!this.proxies[key]) {
     this.add(options);
-
-  }    
-
+  }
+
   proxy = this.proxies[key];
   proxy.proxyRequest(req, res, options.buffer);
 };
@@ -206,7 +224,7 @@ RoutingProxy.prototype.proxyRequest = function (req, res, options) {
 //
 RoutingProxy.prototype.proxyWebSocketRequest = function (req, socket, head, options) {
   options = options || {};
-  
+
   if (this.proxyTable && !options.host) {
     location = this.proxyTable.getProxyLocation(req);
 
@@ -217,15 +235,15 @@ RoutingProxy.prototype.proxyWebSocketRequest = function (req, socket, head, opti
     options.port = location.port;
     options.host = location.host;
   }
-  
+
   var key = this._getKey(options),
     proxy;
 
   if (!this.proxies[key]) {
     this.add(options);
   }
 
-  proxy = this.proxies[key];      
+  proxy = this.proxies[key];
   proxy.proxyWebSocketRequest(req, socket, head, options.buffer);
 };
 
@@ -237,14 +255,14 @@ RoutingProxy.prototype.proxyWebSocketRequest = function (req, socket, head, opti
 // combination contained within.
 //
 RoutingProxy.prototype._getKey = function (options) {
-  if (!options || ((!options.host || !options.port) 
+  if (!options || ((!options.host || !options.port)
     && (!options.target || !options.target.host || !options.target.port))) {
     throw new Error('options.host and options.port or options.target are required.');
     return;
   }
 
   return [
-    options.host || options.target.host, 
+    options.host || options.target.host,
     options.port || options.target.port
   ].join(':');
 }