HTML5 localStorage AJAX Cache

engine.js

function getTime(){
    return ((new Date().valueOf() * 0.001)|0);
}

function cacheTime(key,time){
    /* @TODO: Compare client/server cache ages! */
    if((!window.localStorage.getItem('cache-ttl')) || !window.localStorage.getItem('cache-ttl').match(/(\{).+(\})/)){
        var cacheTTL = {};
    }
    else{
        var cacheTTL = JSON.parse(window.localStorage.getItem('cache-ttl'));
    }
    
    if(typeof(time)==='number'){
        cacheTTL[key] = time;
        window.localStorage.setItem('cache-ttl', JSON.stringify(cacheTTL));
    }
    return cacheTTL[key];
}

function dataCache(key, callback){
    if(window.localStorage.getItem(key) === null){
        $.ajax({
            jsonpCallback: key
        }).done(function(response){
            cacheTime(key, getTime());
            window.localStorage.setItem(key, JSON.stringify(response));
            callback(response);
        });
    }
    else{
        if(!window.localStorage.getItem(key).match(/(\[).+(\])/) || (checkConnection() && (((getTime()-cacheTime(key)) > (60*15)) || !cacheTime(key)))){
            cacheTime(key, 0);
            window.localStorage.removeItem(key);
            dataCache(key,callback);
            return false;
        }
        var data = $.parseJSON(window.localStorage.getItem(key));
        callback(data);
    }
}

function checkConnection(){
    $.ajax({
        jsonpCallback: 'reachable'
    }).success(function(reachable){
        if(reachable){
            window.localStorage.setItem('online', getTime());
        }
        return true;
    }).error(function(){
        window.localStorage.setItem('online','');
        return false;
    });
//    return navigator.connection.type;
}

view.js

function loadTemplate(data){
    var template = $("#template").html();
    $("#template").html(_.template(template,{data: data}));
}

dataCache('data-key',loadTemplate);