如何取消订阅 socket.io 订阅? [英] How to unsubscribe from a socket.io subscription?

问题描述

假设有像这样订阅套接字服务器的对象:

Suppose there are objects making subscriptions to a socket server like so:

socket.on('news', obj.socketEvent)

这些对象的生命周期很短并且经常被创建，从而产生很多订阅.这看起来像是内存泄漏和容易出错的情况，可以通过这种方式直观地防止:

These objects have a short life span and are frequently created, generating many subscriptions. This seems like a memory leak and an error prone situation which would intuitively be prevented this way:

socket.off('news', obj.socketEvent)

在对象被删除之前，但可惜的是，套接字中没有 off 方法.有没有其他方法可以解决这个问题?

before the object is deleted, but alas, there isn't an off method in the socket. Is there another method meant for this?

编辑:没有找到答案，我正在分配一个空白方法来覆盖原始事件处理程序的包装方法，示例如下.

Edit: having found no answer I'm assigning a blank method to overwrite the wrapper method for the original event handler, an example follows.

var _blank = function(){};

var cbProxy = function(){
    obj.socketEvent.apply(obj, arguments)
};
var cbProxyProxy = function(){
    cbProxy.apply ({}, arguments)
}
socket.on('news', cbProxyProxy);

// ...and to unsubscribe 
cbProxy = _blank;

推荐答案

从socket.io.js的源码看(在任何地方的文档中都找不到)，我找到了这两个功能:

From looking at the source of socket.io.js (couldn't find it in documentation anywhere), I found these two functions:

removeListener = function(name, fn)
removeAllListeners = function(name)

我在我的应用中成功使用了 removeAllListeners；您应该可以从以下选项中进行选择:

I used removeAllListeners successfully in my app; you should be able to choose from these:

socket.removeListener("news", cbProxy);
socket.removeAllListeners("news");

另外，我认为您的 cbProxy = _blank 解决方案实际上行不通；这只会影响 cbProxy 变量，不会影响任何实际的 socket.io 事件.

Also, I don't think your solution of cbProxy = _blank would actually work; that would only affect the cbProxy variable, not any actual socket.io event.

这篇关于如何取消订阅 socket.io 订阅?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！