Save and load JSON value with URL hash (aka URL fragment)

hash_accessor.js

/**
 * Save and load JSON value with URL hash (aka URL fragment)
 *
 * hash_accessor.load()    -> load
 * hash_accessor.save(obj) -> save serialized obj into hash
 */

var hash_accessor = (function (window) {
    return {
        load: function () {
            try {
                // strip ^#
                var json_str_escaped = window.location.hash.slice(1);
                // unescape
                var json_str = decodeURIComponent(json_str_escaped);
                return JSON.parse(json_str);
            } catch (e) {
                return {};
            }
        },
        save: function (obj) {
            // use replace so that previous url does not go into history
            window.location.replace('#' + JSON.stringify(obj));
        }
    };
})(window);