Anki - persistent data between front and back

anki-persistent-data.js

// Inspired by https://github.com/SimonLammer/anki-persistence
// A much dumber variant to reduce the amount of code on the card.
// Basically just native sessionStorage and a global object
// fallback with a matching API.

window.valueStore = (function (win) {
  try {
    return win.sessionStorage;
  } catch (e) {}
  win.vso = win.vso || {};
  return {
    setItem: function (key, val) {
      win.vso[key] = String(val);
    },
    getItem: function (key) {
      return win.vso[key];
    },
    removeItem: function (key) {
      delete win.vso[key];
    },
    clear: function () {
      for (k in win.vso) {
        delete win.vso[k];
      }
    }
  };
}(window));

minified.js

window.valueStore=function(w){try{return w.sessionStorage}catch(e){}return w.vso=w.vso||{},{setItem:function(k,v){w.vso[k]=String(v)},getItem:function(k){return w.vso[k]},removeItem:function(k){delete w.vso[k]},clear:function(){for(k in w.vso)delete w.vso[k]}}}(window);