Cache getJSON calls

cache-get-json.js

var fetchCache = {};
function fetchJSON(url, callback, secondsToCache) {
  secondsToCache = secondsToCache ? secondsToCache : 60*60; //default to one hour
  var nowInSeconds = Math.round(new Date().getTime() / 1000);
  if (!fetchCache[url] || ((fetchCache[url].timestamp + secondsToCache) < nowInSeconds)) {
    $.getJSON(url, function(response) {
      fetchCache[url] = {response: response, timestamp: nowInSeconds};
      callback(fetchCache[url].response);
    });
  }
  else {
    callback(fetchCache[url].response);
  }
}