是否有一个javascript客户端库，用于排队具有存储支持的Ajax请求

I'm looking for a javascript client side lib to handle an ajax or websocket requests queue like this :

我正在寻找一个javascript客户端lib来处理像这样的ajax或websocket请求队列：

directly transmit request when user is online and the server is up
当用户在线且服务器启动时直接传输请求
store requests when user is offline or server is down using local storage
当用户离线或服务器因使用本地存储而关闭时存储请求
send stored requests when user is online and server is back online
当用户在线且服务器重新联机时发送存储的请求

Ideally :

理想情况下：

without jquery
没有jquery
I'm also looking for a serverside component to go along
我也在寻找一个服务器端组件

I can't find anything like this. Should I build one myself using localstorage, window.navigator.onLine and socket.io for instance or is there already some lib for that purpose ?

我找不到这样的东西。我应该自己使用localstorage构建一个，例如window.navigator.onLine和socket.io还是已经有一些用于此目的的lib？

Thanks.

谢谢。

1 个解决方案

#1

The question is probably going to be closed, since asking for a library is usually not welcomed on *. However, this is a fun little challenge. (Took me ~15 minutes to complete.)

问题可能会被关闭，因为在*上通常不欢迎要求库。然而，这是一个有趣的小挑战。（花了我大约15分钟才完成。）

This is actually not a very big task to handle, barely 50 lines or so. That's probably why you can't find a small library doing this.

这实际上不是一个很难处理的任务，只有50行左右。这可能就是为什么你找不到这样做的小型图书馆的原因。

function Sender() {
    var requests = [],
        state = 0; // 0 = closed, 1 = open
        ws = new WebSocket();

    ws.onopen = function() {
        state = 1;
        if (requests.length) {
            send();
        }
    };

    ws.onerror = function() {
        if (ws.readyState !== 1) { // 1 is "OPEN"
            close();
        }
    };

    // Let's fill in the requests array if necessary
    // IIFE because I don't want to pollute the scope with `req`
    (function() {
        var req = JSON.parse(localStorage.get('queue'));
        if (req.length) {
            requests = requests.concat(req);
        }
    }());

    return {
        send: function(msg) {
            if (state === 0) {
                requests.push(msg);
            }
            else {
                send();
            }
        },
        close: function() {
            state = 0;
            localStorage.set('queue', JSON.stringify(requests));
        }
    };

    function send() {
        var done = false;
        while (!done) {
            if (state === 1) {
                ws.send(requests.pop());
                if (!requests.length) {
                    done = true;
                }
            }
            else {
                done = true;
            }
        }
    }
}

// Usage example
var sender = Sender();
sender.send('message');

// let's say your "disconnect" button is in a variable
disconnect.addEventListener('click', function() {
    sender.close();
}, false);

The server doesn't have to handle anything except normal requests. If you want, you can add a timestamp to the message you send, this way it's quite easy (2 lines or so) to keep track of the time.

除正常请求外，服务器不必处理任何事情。如果需要，可以为发送的消息添加时间戳，这样可以很容易地（2行左右）跟踪时间。

#1