Quick run-through of syncing a Backbone.Collection with a localStorage cache

backbone-localstorage-sync.js

// Assumes http://brian.io/lawnchair/ and http://backbonejs.org/

var collection = new MyCollection();
var localStore = new Lawnchair({ name: 'my-cache' }, $.noop);

// First load from the cache, then fetch
function initialLoad() {
  localStore.all(function(items) {
    collection.reset(items, function() {
      collection.fetch();
    });
  });
}

collection.on('reset', function() {
  localStore.nuke(function() {
    localStore.batch(collection.toJSON());
  });
});

collection.on('add', function(model) {
  model.set('key', model.get('some-non-id-field-usable-as-pkey')); // Date.now() does nicely in demos
  localStore.save(model.toJSON());
});

collection.on('sync', function(model) {
  localStore.save(model.toJSON());
});