socket.io客户端事件未启动

Question

我试图在没有连接服务器的情况下运行我的客户端(故意(，并捕获ERR_CONNECTION_REFUSED错误并将其显示给用户。我在这里读到，这可以使用套接字事件来实现，特别是connect_error

在我的代码中，我永远无法启动事件并在其中显示控制台日志。日志this.io.socket打印内容，但没有一个事件打印内容。为什么？

$.ajax(args)
.done((msg) => {
this.io.socket.on('connect', msg => {
console.log('connect socket io', msg)
})
resolve(msg);
})
.fail((jqXHR, msg) => {
return new Promise((resolve, reject) => {
console.log('inside promise of fail() - this.io.socket', this.io.socket) // this will log data to console
this.io.socket.on('connect_error', msg => {
console.log('connect_error socket io', msg)
})
this.io.socket.on('connect_failed', (msg) => {
console.log('connect_failed', msg);
});
// return some error here for user
})
});

Answer 1

据我所见，只有当您的第一次ajax调用得到错误响应时，您才试图连接事件处理程序。这不会导致启动任何socket.io事件处理程序。

将事件处理程序移动到初始化套接字实例的代码中。

请参阅下面的完整示例，其中所有manager和socket事件都将记录到控制台。

$.ajax(args)
.done((msg) => {
// connect to your server
const socket = io('http://localhost:3000', {
transports: ['websocket']
});
// manager events
//_________________________________________________________________________________________________
socket.io.on('connect_error', (err) => {
console.error(`manager:connect_error ${err}`);
});
socket.io.on('connect_timeout', () => {
console.error(`manager:connect_timeout`);
});
socket.io.on('reconnect_attempt', (attempt) => {
console.error(`manager:reconnect_attempt ${attempt}`);
});
socket.io.on('reconnecting', (attempt) => {
console.error(`manager:reconnecting ${attempt}`);
});
socket.io.on('reconnect_error', (err) => {
console.error(`manager:reconnect_error ${err}`);
});
socket.io.on('reconnect_failed', () => {
console.error(`manager:reconnect_failed`);
});
//_________________________________________________________________________________________________
// socket events
//_________________________________________________________________________________________________
socket.on('connect', () => {
console.log(`socket:connect ${socket.connected}`);
});
socket.on('connect_error', (err) => {
console.error(`socket:connect_error ${err}`);
});
socket.on('connect_timeout', (timeout) => {
console.error(`socket:connect_timeout ${timeout}`);
});
socket.on('error', (err) => {
console.error(`socket:error ${err}`);
});
socket.on('disconnect', (reason) => {
console.info(`socket:disconnect ${reason}`);
if (reason === 'io server disconnect') {
// the disconnection was initiated by the server, you need to reconnect manually
socket.connect();
}
// else the socket will automatically try to reconnect
});
socket.on('reconnect', (attempt) => {
console.error(`socket:reconnect ${attempt}`);
});
socket.on('reconnect_attempt', (attempt) => {
console.error(`socket:reconnect_attempt ${attempt}`);
});
socket.on('reconnecting', (attempt) => {
console.error(`socket:reconnecting ${attempt}`);
});
socket.on('reconnect_error', (err) => {
console.error(`socket:reconnect_error ${err}`);
});
socket.on('reconnect_failed', () => {
console.error(`socket:reconnect_failed`);
});
//_________________________________________________________________________________________________
// custom events
//_________________________________________________________________________________________________
socket.on('hello', (message) => {
console.info(message);
socket.emit('hello', {foo: 'baz'});
});
//_________________________________________________________________________________________________
resolve(msg);
})
.fail((jqXHR, msg) => {
console.error(msg);
});