web socket update

websockets/example.md

@@ -6,6 +6,61 @@ currentMenu: websockets-example
 
 Below are some examples of WebSockets in use.
 
+## Droplet
+
+Creating a WebSocket server with the Droplet is easy. WebSockets work by upgrading an HTTP request to a WebSocket connection.
+
+Because of this, you should pick a URL for your WebSocket server to reside at. In this case, we use `/ws`.
+
+```swift
+import Vapor
+
+let drop = Droplet()
+
+drop.socket("ws") { req, ws in
+    print("New WebSocket connected: \(ws)")
+
+    // ping the socket to keep it open
+    try background {
+        if ws.state == .open {
+            try? ws.ping()
+            drop.console.wait(seconds: 10) // every 10 seconds
+        }
+    }
+
+    ws.onText = { ws, text in
+        print("Text received: \(text)")
+
+        // reverse the characters and send back
+        let rev = String(text.characters.reversed())
+        try ws.send(rev.bytes)
+    }
+
+    ws.onClose = { ws, code, reason, clean in
+        print("Closed.")
+    }
+}
+
+drop.run()
+```
+
+To connect with a WebSocket client, you would open a connection to `ws://<ip>/ws`.
+
+Here is an example using JavaScript.
+
+```js
+
+var ws = new WebSocket("ws://0.0.0.0:8080/ws")
+
+ws.onmessage = function(msg) {
+    console.log(msg)
+}
+
+ws.send('test')
+```
+
+The above will log `tset` (`test` reversed).
+
 ## Client
 
 ```Swift