javascript - 在将socket.io错误发送到控制台之前，我可以捕获它吗？

Question

我在客户端上有一个非常简单的socket.io代码片段:

   setUpSockets () {
    this.socket = io();
    this.socket.on('beacon', (data) => {
      console.log('DEBUG: beacon event received: ', data);
    });
    console.log("DEBUG: socket created: event handler ready ");
  }

当我的服务器出现故障时，我开始出现此错误:



我特意使服务器停机以表征错误。我只想捕获一次并记录自己的错误1次。

这可能吗？

Answer 1

您可以利用各种经理事件，然后针对您的情况采取适当的措施。

如果客户端失去与服务器的连接，则不会得到它掉线的原因-例如服务器崩溃，客户端脱机等-您只会得到reconnecting事件，可以在客户端上点击并显示适当的消息传递。但是，您可以强制断开客户端与服务器的连接，并利用客户端的原因-查看下面包含的Socket disconnect事件。

以下是一些代码片段，您可以查看这些代码以查看可以挂接到的各种事件:

    let socket = io('http://localhost:3000', {autoConnect: false});

    const enums = {
        status: {
            success: 'success',
            fail: 'fail',
            error: 'error',
            warn: 'warn'
        }
    };

    function log(message, when, status) {
        status = status || 'success';

        switch (status) {
            case 'fail':
            case 'error':
                console.error(message);
                break;
            case 'success':
                console.info(message);
                break;
            case 'warn':
                console.warn(message);
                break;
        }
        // additional logging etc
    }

    function registerEventHandlers() {
            // manager events
            //_________________________________________________________________________________________________
            socket.io.on('connect_error', (err) => {
                log(`manager:connect_error ${err.message}`, null, enums.status.error);
            });

            socket.io.on('connect_timeout', () => {
                log(`manager:connect_timeout`, null, enums.status.error);
            });

            socket.io.on('reconnect_attempt', (attempt) => {
                log(`manager:reconnect_attempt ${attempt}`, null, enums.status.warn);
            });

            socket.io.on('reconnecting', (attempt) => {
                log(`manager:reconnecting ${attempt}`, null, enums.status.warn);
            });

            socket.io.on('reconnect_error', (err) => {
                log(`manager:reconnect_error ${err.message}`, null, enums.status.error);
            });

            socket.io.on('reconnect_failed', () => {
                log(`manager:reconnect_failed`, null, enums.status.error);
            });
            //_________________________________________________________________________________________________

            // socket events
            //_________________________________________________________________________________________________
            socket.on('connect', () => {
                authContainer.classList.add('hide');

                log(`socket:connect ${socket.connected}`, null);
            });

            socket.on('connect_error', (err) => {
                log(`socket:connect_error ${err.message}`, null, enums.status.error);
            });

            socket.on('connect_timeout', (timeout) => {
                log(`socket:connect_timeout ${timeout}`, null, enums.status.error);
            });

            socket.on('error', (err) => {
                if (err.type === 'UnauthorizedError' || err.code === 'invalid_token') {
                    log(`socket:error:invalid_token ${err.message}`, null, enums.status.error);
                }

                log(`socket:error ${err.message}`, null, enums.status.error);
            });

            socket.on('disconnect', (reason) => {
                log(`socket:disconnect ${reason}`, null);
                if (reason === 'io server disconnect') {
                    // the disconnection was initiated by the server
                    socket.close();

                    return reset();
                }
                // else the socket will automatically try to reconnect
            });

            socket.on('reconnect', (attempt) => {
                log(`socket:reconnect ${attempt}`, null, enums.status.warn);
            });

            socket.on('reconnect_attempt', (attempt) => {
                log(`socket:reconnect_attempt ${attempt}`, null, enums.status.warn);
            });

            socket.on('reconnecting', (attempt) => {
                log(`socket:reconnecting ${attempt}`, null, enums.status.warn);
            });

            socket.on('reconnect_error', (err) => {
                log(`socket:reconnect_error ${err.message}`, null, enums.status.error);
            });

            socket.on('reconnect_failed', () => {
                log(`socket:reconnect_failed`, null, enums.status.error);
            });
            //_________________________________________________________________________________________________
        }

        socket.open();