Collection.prototype.storeOfflineData = function(collectionId){
   var formData = new FormData($('form')[0]);
   pendingSites = {"collectionId" : collectionId, "formData" : formData};
   window.localStorage.setItem("offlineSites", JSON.stringify(pendingSites));
   Collection.prototype.goHome();
   Collection.prototype.showErrorMessage("Successfully store data in offline.");
}

Collection.prototype.pushingPendingSites = function(){
  pendingSites = JSON.parse(window.localStorage.getItem("offlineSites"));
  if(pendingSites != null){
    console.log(pendingSites[i]["formData"]);
    Collection.prototype.ajaxCreateSite(pendingSites[i]["collectionId"], pendingSites[i]["formData"]);
  }
}

Collection.prototype.ajaxCreateSite = function(collectionId, formData){
  $.ajax({
    url: '/mobile/collections/' + collectionId + '/sites',  //Server script to process data
    type: 'POST',
    success: function(){
      Collection.prototype.goHome();
      Collection.prototype.showErrorMessage("Successfully saved.");
    },
    error: function(data){
      Collection.prototype.showErrorMessage("Save new site failed!");
    },
    data: formData,
    cache: false,
    contentType: false,
    processData: false
  });
}