add iris websocket client side for Go and a simple chat example

Former-commit-id: af1c555b6b092a3d0484fee2e200fd8767d7239e

_examples/README.md

@@ -478,6 +478,9 @@ iris websocket library lives on its own [package](https://github.com/kataras/iri
 The package is designed to work with raw websockets although its API is similar to the famous [socket.io](https://socket.io). I have read an article recently and I felt very contented about my decision to design a **fast** websocket-**only** package for Iris and not a backwards socket.io-like package. You can read that article by following this link: https://medium.com/@ivanderbyl/why-you-don-t-need-socket-io-6848f1c871cd.
 
 - [Chat](websocket/chat/main.go)
+- [Chat with Iris Go Client Side](websocket/go-client) **NEW**
+    * [Server](websocket/go-client/server/main.go)
+    * [Client](websocket/go-client/client/main.go)
 - [Native Messages](websocket/native-messages/main.go)
 - [Connection List](websocket/connectionlist/main.go)
 - [TLS Enabled](websocket/secure/main.go)

_examples/README_ZH.md

@@ -431,6 +431,9 @@ iris websocket库依赖于它自己的[包](https://github.com/kataras/iris/tree
 决定给iris设计一个**快速的**websocket**限定**包并且不是一个向后传递类socket.io的包。你可以阅读这个链接里的文章https://medium.com/@ivanderbyl/why-you-don-t-need-socket-io-6848f1c871cd。
 
 - [聊天](websocket/chat/main.go)
+- [Chat with Iris Go Client Side](websocket/go-client) **NEW**
+    * [Server](websocket/go-client/server/main.go)
+    * [Client](websocket/go-client/client/main.go)
 - [原生消息](websocket/native-messages/main.go)
 - [连接列表](websocket/connectionlist/main.go)
 - [TLS支持](websocket/secure/main.go)

_examples/websocket/custom-go-client/main.go

@@ -87,7 +87,7 @@ func SendMessage(serverID, to, method, message string) error {
 
 // SendtBytes broadcast a message to server
 func SendtBytes(serverID, to, method string, message []byte) error {
-	// look https://github.com/kataras/iris/blob/master/websocket/message.go , client.go and client.js
+	// look https://github.com/kataras/iris/blob/master/websocket/message.go , client.js.go and client.js
 	// to understand the buffer line:
 	buffer := []byte(fmt.Sprintf("%s%v;0;%v;%v;", websocket.DefaultEvtMessageKey, method, serverID, to))
 	buffer = append(buffer, message...)

_examples/websocket/go-client/client/main.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+
+	"github.com/kataras/iris/websocket"
+)
+
+const (
+	url    = "ws://localhost:8080/socket"
+	prompt = ">> "
+)
+
+/*
+How to run:
+Start the server, if it is not already started by executing `go run ../server/main.go`
+And open two or more terminal windows and start the clients:
+$ go run main.go
+>> hi!
+*/
+func main() {
+	conn, err := websocket.Dial(url, websocket.DefaultEvtMessageKey)
+	if err != nil {
+		panic(err)
+	}
+
+	conn.OnError(func(err error) {
+		fmt.Printf("error: %v", err)
+	})
+
+	conn.OnDisconnect(func() {
+		fmt.Println("Server was force-closed[see ../server/main.go#L19] this connection after 20 seconds, therefore I am disconnected.")
+		os.Exit(0)
+	})
+
+	conn.On("chat", func(message string) {
+		fmt.Printf("\n%s\n", message)
+	})
+
+	fmt.Println("Start by typing a message to send")
+	scanner := bufio.NewScanner(os.Stdin)
+	for {
+		fmt.Print(prompt)
+		if !scanner.Scan() || scanner.Err() != nil {
+			break
+		}
+		msgToSend := scanner.Text()
+		if msgToSend == "exit" {
+			break
+		}
+
+		conn.Emit("chat", msgToSend)
+	}
+
+	fmt.Println("Terminated.")
+}

_examples/websocket/go-client/server/main.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/kataras/iris"
+	"github.com/kataras/iris/websocket"
+)
+
+func main() {
+	app := iris.New()
+	ws := websocket.New(websocket.Config{})
+	app.Get("/socket", ws.Handler())
+
+	ws.OnConnection(func(c websocket.Connection) {
+		go func() {
+			<-time.After(20 * time.Second)
+			c.Disconnect()
+		}()
+
+		c.On("chat", func(message string) {
+			c.To(websocket.Broadcast).Emit("chat", c.ID()+": "+message)
+		})
+
+		c.OnDisconnect(func() {
+			fmt.Printf("Connection with ID: %s has been disconnected!\n", c.ID())
+		})
+	})
+
+	app.Run(iris.Addr(":8080"))
+}