Cached JSON via jQuery

cachedjson.js

var getCachedJSON = function (url) {
    var deferred = new $.Deferred();
    var cachedData = window.localStorage[url];
    if (cachedData) {
        log('Data already cached, returning from cache:', url);
        deferred.resolve(JSON.parse(cachedData));
    } else {
        $.getJSON(url, function(data) {
            log('Fetched data, saving to cache:', url);
            window.localStorage[url] = JSON.stringify(data);
            deferred.resolve(data);
        });
    }
    return deferred.promise();
};