store.js

var items = []

var notifyComponents = function() {
  $(ListStore).trigger('storeHasChanged')
}

var findItemById = function(id) {
  return items.filter(function(item) {
    return item.id === id
  })[0]
},

ListStore = { 

  getItems: function() {
    return items
  },

  loadItems: function() {
    var loadRequest = $.ajax({
      type: 'GET',
      url: 'https://listalous.herokuapp.com/lists/xiaodianwang/'
    })
    loadRequest.done(function(dataFromServer) {
      items = dataFromServer.items
      notifyComponents()
    })  
  },
  addItem: function(itemDescription) {
    var creationRequest = $.ajax({
      type: 'POST',
      url: 'http://listalous.herokuapp.com/lists/xiaodianwang/items',
      data: { description: itemDescription, completed: false}
    })
    creationRequest.done(function(itemDataFromServer) {
      items.push(itemDataFromServer)
      notifyComponents()
    })
  },
  toggleCompleteness: function(itemId) {
    var item = findItemById(itemId)
    var currentCompletedValue = item.completed
    var updateRequest = $.ajax({
      type: 'PUT',
      url: 'https://listalous.herokuapp.com/lists/xiaodianwang/items/' + itemId,
      data: {completed: !currentCompletedValue}
    })
    updateRequest.done(function (itemData) {
      item.completed = itemData.completed
      notifyComponents()
    })
  }

  deleteItem: function(itemId) {
    var item = findItemById(itemId)
    var deleteRequest = $.ajax({
      type: 'DELETE',
      url: 'http://listalous.herokuapp.com/lists/xiaodianwang/items/' + itemId,
    })
  }
}