YII框架的WebSocket是什么？YII框架如何实现实时通信？

websocket_server.php

<?php
require_once __DIR__ . '/vendor/autoload.php'; // Workerman autoload

use Workerman\Worker;
use Workerman\Connection\TcpConnection;

// 全局存储用户连接，以便按用户ID推送
global $userConnections;
$userConnections = [];

$ws_worker = new Worker("websocket://0.0.0.0:2346");
$ws_worker->onConnect = function(TcpConnection $connection) {
    echo "New connection\n";
};

$ws_worker->onMessage = function(TcpConnection $connection, $data) {
    // 收到消息，通常是客户端发送的认证信息或心跳
    $message = json_decode($data, true);
    if (isset($message['type']) && $message['type'] === 'auth' && isset($message['user_id'])) {
        $userId = $message['user_id'];
        $connection->userId = $userId; // 将用户ID绑定到连接对象
        $userConnections[$userId] = $connection;
        echo "User {$userId} connected.\n";
    }
    // 也可以处理其他类型的消息，比如客户端发送的聊天内容，然后通过Yii API存储
};

$ws_worker->onClose = function(TcpConnection $connection) {
    if (isset($connection->userId) && isset($userConnections[$connection->userId])) {
        unset($userConnections[$connection->userId]);
        echo "User {$connection->userId} disconnected.\n";
    }
    echo "Connection closed\n";
};

// 启动一个内部TCP服务器，用于Yii应用向WebSocket服务器发送指令
$inner_http_worker = new Worker("http://0.0.0.0:2347");
$inner_http_worker->onMessage = function(TcpConnection $connection, $data) {
    global $userConnections;
    $request = json_decode($data, true); // 假设Yii发送的是JSON数据
    if (isset($request['action']) && $request['action'] === 'pushMessage') {
        $message = $request['message'];
        $targetUserId = $request['targetUserId'] ?? null;

        if ($targetUserId && isset($userConnections[$targetUserId])) {
            $userConnections[$targetUserId]->send(json_encode(['type' => 'chat', 'content' => $message]));
            $connection->send("Message sent to user {$targetUserId}");
        } elseif (!$targetUserId) { // 广播
            foreach ($userConnections as $conn) {
                $conn->send(json_encode(['type' => 'chat', 'content' => $message]));
            }
            $connection->send("Message broadcasted.");
        } else {
            $connection->send("User {$targetUserId} not found or not online.");
        }
    } else {
        $connection->send("Invalid action.");
    }
};

Worker::runAll();

ChatController.php

<?php
namespace app\controllers;

use Yii;
use yii\web\Controller;
use yii\httpclient\Client; // 需要安装 yii2-httpclient

class ChatController extends Controller
{
    public function actionSendMessage()
    {
        $request = Yii::$app->request;
        if ($request->isPost) {
            $messageContent = $request->post('message');
            $targetUserId = $request->post('target_user_id'); // 目标用户ID，如果为null则广播

            // 1. 将消息存入数据库 (Yii的正常业务逻辑)
            // $chatMessage = new ChatMessage();
            // $chatMessage->content = $messageContent;
            // $chatMessage->sender_id = Yii::$app->user->id;
            // $chatMessage->save();

            // 2. 通知WebSocket服务器推送消息
            $client = new Client();
            $response = $client->createRequest()
                ->setMethod('POST')
                ->setUrl('http://127.0.0.1:2347') // Workerman内部HTTP接口地址
                ->setData([
                    'action' => 'pushMessage',
                    'message' => $messageContent,
                    'targetUserId' => $targetUserId,
                ])
                ->send();

            if ($response->isOk) {
                Yii::$app->session->setFlash('success', '消息已发送并尝试推送。');
            } else {
                Yii::$app->session->setFlash('error', '消息发送成功，但推送失败：' . $response->content);
            }
            return $this->redirect(['index']); // 重定向到聊天页面
        }
        return $this->render('send-message-form'); // 渲染发送消息表单
    }
}

chat.js

const ws = new WebSocket("ws://localhost:2346"); // 连接到Workerman WebSocket服务

ws.onopen = function() {
    console.log("WebSocket connection opened.");
    // 认证：发送当前用户的ID给服务器
    const userId = "your_current_user_id"; // 替换为实际的用户ID，从Yii页面获取
    ws.send(JSON.stringify({ type: 'auth', user_id: userId }));
};

ws.onmessage = function(event) {
    const data = JSON.parse(event.data);
    if (data.type === 'chat') {
        console.log("Received chat message:", data.content);
        // 在页面上显示消息
        const chatBox = document.getElementById('chat-messages');
        const messageElement = document.createElement('div');
        messageElement.textContent = data.content;
        chatBox.appendChild(messageElement);
    }
};

ws.onclose = function() {
    console.log("WebSocket connection closed.");
};

ws.onerror = function(error) {
    console.error("WebSocket error:", error);
};

// 假设有一个发送按钮
document.getElementById('send-button').onclick = function() {
    const messageInput = document.getElementById('message-input');
    const message = messageInput.value;
    if (message) {
        // 客户端发送消息到Yii后端（通过HTTP POST），Yii再通知WebSocket服务器
        fetch('/chat/send-message', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/x-www-form-urlencoded',
                'X-CSRF-Token': document.querySelector('meta[name="csrf-token"]').getAttribute('content') // Yii CSRF token
            },
            body: `message=${encodeURIComponent(message)}&target_user_id=` // 如果是广播，target_user_id留空
        }).then(response => response.text())
          .then(data => {
              console.log('Message sent via HTTP:', data);
              messageInput.value = '';
          });
    }
};