使用PHP WebSocket实现多设备实时更新

// 假设WebSocket服务器运行在 ws://your-websocket-server.com:8080
const socket = new WebSocket('ws://your-websocket-server.com:8080');

socket.onopen = function(event) {
    console.log('WebSocket connection established.');
    // 可以在此处发送消息给服务器，例如订阅某个频道
    // socket.send(JSON.stringify({ type: 'subscribe', channel: 'user_updates_123' }));
};

socket.onmessage = function(event) {
    const message = JSON.parse(event.data);
    console.log('Received message from server:', message);

    // 根据消息类型和内容更新UI
    if (message.type === 'broadcast_update' && message.channel === 'user_updates_123') {
        alert('New update for channel user_updates_123: ' + message.data);
        // 执行DOM更新或其他客户端逻辑
    }
};

socket.onclose = function(event) {
    console.log('WebSocket connection closed.', event);
    // 尝试重连
    setTimeout(() => {
        console.log('Attempting to reconnect...');
        // 重新初始化WebSocket连接
        // initWebSocket(); // 假设有一个初始化函数
    }, 5000);
};

socket.onerror = function(error) {
    console.error('WebSocket error:', error);
};

// 如果需要发送消息给服务器，例如通知服务器该客户端属于哪个用户或订阅哪个频道
function sendSubscriptionInfo(userId) {
    if (socket.readyState === WebSocket.OPEN) {
        socket.send(JSON.stringify({
            action: 'register',
            userId: userId,
            channels: ['general', `user_${userId}`] // 订阅通用频道和用户专属频道
        }));
    }
}

// 示例：页面加载后发送订阅信息
// sendSubscriptionInfo('current_logged_in_user_id');

<?php

// 假设这是你的PHP后端业务逻辑文件
// ... 执行数据库更新或其他操作 ...

$update_data = [
    'type'    => 'broadcast_update',
    'channel' => 'user_updates_123', // 广播到特定频道
    'data'    => 'User profile updated successfully at ' . date('H:i:s')
];

// 方法一：使用WebSocket服务器提供的PHP客户端库（推荐）
// 假设 napengam/phpWebSocketServer 提供了这样的客户端
try {
    $wsClient = new \Napengam\WebSocket\Client('127.0.0.1', 8080); // 连接到WebSocket服务器
    $wsClient->send(json_encode($update_data));
    echo "Update message sent to WebSocket server.\n";
} catch (\Exception $e) {
    error_log("Failed to send message to WebSocket server: " . $e->getMessage());
}


// 方法二：如果WebSocket服务器提供了HTTP API来触发广播（不常见，但可行）
/*
$url = 'http://your-websocket-server.com:8080/broadcast'; // 假设的HTTP广播接口
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($update_data));
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
$response = curl_exec($ch);
if (curl_errno($ch)) {
    error_log('Error sending broadcast via HTTP: ' . curl_error($ch));
} else {
    echo "Broadcast triggered via HTTP. Response: " . $response . "\n";
}
curl_close($ch);
*/

?>

// 这是一个高度简化的概念性服务器端广播逻辑
// 实际实现会复杂得多，包含连接管理、心跳、错误处理等

class MyWebSocketServer {
    private $clients = []; // 存储所有连接的客户端
    private $channels = []; // 存储频道订阅信息

    public function onMessage($client, $message) {
        $data = json_decode($message, true);

        if ($data['action'] === 'register') {
            // 客户端注册并订阅频道
            $this->clients[$client->id] = $client;
            foreach ($data['channels'] as $channel) {
                $this->channels[$channel][$client->id] = $client;
            }
            echo "Client {$client->id} registered and subscribed to " . implode(', ', $data['channels']) . "\n";
        } elseif ($data['type'] === 'broadcast_update') {
            // 收到来自PHP后端的广播请求
            $targetChannel = $data['channel'];
            $messageToBroadcast = json_encode($data);

            if (isset($this->channels[$targetChannel])) {
                foreach ($this->channels[$targetChannel] as $subscribedClient) {
                    $subscribedClient->send($messageToBroadcast); // 向订阅者发送消息
                    echo "Broadcasted to client {$subscribedClient->id} on channel {$targetChannel}\n";
                }
            }
        }
    }

    // ... 其他连接管理、断开处理等方法 ...
}