Backbone.js：如何将挂起的同步事件排队到服务器？

Question

I would like my Backbone.js based web app to function offline. Upon detecting offline state, how can I queue up Backbone's sync events so that they're sent to the server after connectivity is restored?

Answer 1

You can use two Backbone.sync methods and swap them out depending on offline/online state:

// Detect sync however you want here
var state = getInternetConnectivityState();

// Save off a local copy of the default Backbone.sync
var ajaxSync = Backbone.sync;

// Create a new Backbone.sync function that works with local storage. I would suggest
// using store.js as it works x-browser, takes care of JSON serialization and is well  
// supported
var localSync = function(method, model, options) {
    if ('GET' === method) {
        model.set('name', store.get(model.id).name);
    }
    ...
}

Backbone.sync = function() {
    if ('offline' === getInternetConnectivityState()) {
        localSync.call(this, arguments);
    }
    else {
        ajaxSync.call(this, arguments);
    }
}