jQuery.getJSON abstraction to cache data to localStorage

gistfile1.js

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

This best