Socket.io

用于 Fiber 的 WebSocket 封装，支持事件，灵感来自 Socket.io

注意：需要 Go 1.20 及以上版本

安装

go get -u github.com/gofiber/fiber/v2
go get -u github.com/gofiber/contrib/socketio

签名

// Initialize new socketio in the callback this will
// execute a callback that expects kws *Websocket Object
// and optional config websocket.Config
func New(callback func(kws *Websocket), config ...websocket.Config) func(*fiber.Ctx) error

// Add listener callback for an event into the listeners list
func On(event string, callback func(payload *EventPayload))

// Emit the message to a specific socket uuids list
// Ignores all errors
func EmitToList(uuids []string, message []byte)

// Emit to a specific socket connection
func EmitTo(uuid string, message []byte) error

// Broadcast to all the active connections
// except avoid broadcasting the message to itself
func Broadcast(message []byte)

// Fire custom event on all connections
func Fire(event string, data []byte) 

示例

package main

import (
    "encoding/json"
    "fmt"
    "log"

    "github.com/gofiber/contrib/socketio"
    "github.com/gofiber/contrib/websocket"
    "github.com/gofiber/fiber/v2"
)

// MessageObject Basic chat message object
type MessageObject struct {
    Data  string `json:"data"`
    From  string `json:"from"`
    Event string `json:"event"`
    To    string `json:"to"`
}

func main() {

    // The key for the map is message.to
    clients := make(map[string]string)

    // Start a new Fiber application
    app := fiber.New()

    // Setup the middleware to retrieve the data sent in first GET request
    app.Use(func(c *fiber.Ctx) error {
        // IsWebSocketUpgrade returns true if the client
        // requested upgrade to the WebSocket protocol.
        if websocket.IsWebSocketUpgrade(c) {
            c.Locals("allowed", true)
            return c.Next()
        }
        return fiber.ErrUpgradeRequired
    })

    // Multiple event handling supported
    socketio.On(socketio.EventConnect, func(ep *socketio.EventPayload) {
        fmt.Printf("Connection event 1 - User: %s", ep.Kws.GetStringAttribute("user_id"))
    })

    // Custom event handling supported
    socketio.On("CUSTOM_EVENT", func(ep *socketio.EventPayload) {
        fmt.Printf("Custom event - User: %s", ep.Kws.GetStringAttribute("user_id"))
        // --->

        // DO YOUR BUSINESS HERE

        // --->
    })

    // On message event
    socketio.On(socketio.EventMessage, func(ep *socketio.EventPayload) {

        fmt.Printf("Message event - User: %s - Message: %s", ep.Kws.GetStringAttribute("user_id"), string(ep.Data))

        message := MessageObject{}

        // Unmarshal the json message
        // {
        //  "from": "<user-id>",
        //  "to": "<recipient-user-id>",
        //  "event": "CUSTOM_EVENT",
        //  "data": "hello"
        //}
        err := json.Unmarshal(ep.Data, &message)
        if err != nil {
            fmt.Println(err)
            return
        }

        // Fire custom event based on some
        // business logic
        if message.Event != "" {
            ep.Kws.Fire(message.Event, []byte(message.Data))
        }

        // Emit the message directly to specified user
        err = ep.Kws.EmitTo(clients[message.To], ep.Data, socketio.TextMessage)
        if err != nil {
            fmt.Println(err)
        }
    })

    // On disconnect event
    socketio.On(socketio.EventDisconnect, func(ep *socketio.EventPayload) {
        // Remove the user from the local clients
        delete(clients, ep.Kws.GetStringAttribute("user_id"))
        fmt.Printf("Disconnection event - User: %s", ep.Kws.GetStringAttribute("user_id"))
    })

    // On close event
    // This event is called when the server disconnects the user actively with .Close() method
    socketio.On(socketio.EventClose, func(ep *socketio.EventPayload) {
        // Remove the user from the local clients
        delete(clients, ep.Kws.GetStringAttribute("user_id"))
        fmt.Printf("Close event - User: %s", ep.Kws.GetStringAttribute("user_id"))
    })

    // On error event
    socketio.On(socketio.EventError, func(ep *socketio.EventPayload) {
        fmt.Printf("Error event - User: %s", ep.Kws.GetStringAttribute("user_id"))
    })

    app.Get("/ws/:id", socketio.New(func(kws *socketio.Websocket) {

        // Retrieve the user id from endpoint
        userId := kws.Params("id")

        // Add the connection to the list of the connected clients
        // The UUID is generated randomly and is the key that allow
        // socketio to manage Emit/EmitTo/Broadcast
        clients[userId] = kws.UUID

        // Every websocket connection has an optional session key => value storage
        kws.SetAttribute("user_id", userId)

        //Broadcast to all the connected users the newcomer
        kws.Broadcast([]byte(fmt.Sprintf("New user connected: %s and UUID: %s", userId, kws.UUID)), true, socketio.TextMessage)
        //Write welcome message
        kws.Emit([]byte(fmt.Sprintf("Hello user: %s with UUID: %s", userId, kws.UUID)), socketio.TextMessage)
    }))

    log.Fatal(app.Listen(":3000"))
}

---

支持的事件

常量	事件	描述
EventMessage	message	当接收到文本/二进制消息时触发
EventPing	ping	更多详细信息在此
EventPong	pong	参考 ping 的描述
EventDisconnect	disconnect	断开连接时触发。断开连接事件中提供的错误信息，定义在 RFC 6455 第 11.7 节。
EventConnect	connect	首次连接时触发
EventClose	close	当连接由服务器主动关闭时触发。这与客户端断开连接不同
EventError	error	出现错误时触发，也常用于调试 websockets

事件 Payload 对象

变量	类型	描述
Kws	*Websocket	连接对象
Name	string	事件的名称
SocketUUID	string	唯一的连接 UUID
SocketAttributes	map[string]string	可选的 websocket 属性
Error	error	(可选) 由断开连接或错误事件触发
Data	[]byte	在 Message 和 Error 事件中使用的载荷，包含自定义事件的载荷

Socket 实例函数

Name	类型	描述
SetAttribute	void	为特定的 socket 连接设置一个特定的属性
GetUUID	string	获取 socket 连接的 UUID
SetUUID	error	设置 socket 连接的 UUID
GetAttribute	string	从 socket 属性中获取一个特定的属性
EmitToList	void	将消息发送到特定的 socket UUID 列表
EmitTo	error	发送到特定的 socket 连接
Broadcast	void	广播给所有活跃连接，但不包括广播消息给自己
Fire	void	触发自定义事件
Emit	void	发送/写入消息到给定的连接
Close	void	从服务器主动关闭连接

注意：可以直接从实例访问 FastHTTP 连接

kws.Conn