Backbone.js able to do rest and localstorage?

javascript local-storage offline backbone.js
LeRoy picture LeRoy · Apr 23, 2011 · Viewed 15.5k times · Source

I have been experimenting with the localstorage module for Backbone.js (https://github.com/jeromegn/Backbone.localStorage). As I understand it this overloads Backbone.sync and therefore stops backbone from pushing to the server(?). Ideally, I would like pass my data back to the server as well and persist it locally when online and just use localstorage when offline (you know, the perfect app). I haven't found any documentation yet.

Is Backbone.localStorage a part of this? Has anyone been able to build this scenario? How is this done? (Please tell me I don't have to roll my own.)

Thanks.

Answer

Raynos picture Raynos · Apr 23, 2011

Backbone.localStorage is an external file you can use which overwrites Backbone.Sync.

You can use simple feature detection for whether the user is offline or online and then asynchronously load Backbone.localStorage.js if they are offline.

If neccesary you can also pass in a specific version of Backbone.sync to your models and collections.

If you want to do both at the same time you'll have to write your own version of Backbone.sync that both calls the server and calls localStorage.

The easiest way to do this is to just define

Backbone.sync = function() {
    originalSync.apply(this, arguments);
    localStorageSync.apply(this, arguments);
}

Edit:

As mentioned in the comments, if you use the latest backbone localStorage plugin then you can do the following

Backbone.sync = function Sync() {
    Backbone.ajaxSync.apply(this, arguments);
    return Backbone.localSync.apply(this, arguments);
};

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