poc-first-try-app-before.js

require('./API');
require('./Item');
require('./Category');

const App = {
  selector: '#app',
  fetchAPI: API,
  run(){
    this.fetchAPI
            .categories()
            .then(this.recieveCategories.bind(this)) // cómo se puede preservar el this dentro de las promises? bluebird soporta un bind() pero parece que ES2015 no :(
            .then(this.addItemsToCategories.bind(this))
            .then(this.addCategoriesToList.bind(this))
            .then(this.listToHTML.bind(this))
            .then(this.renderHTML.bind(this));
  },
  recieveCategories(aJSON){
    return aJSON.map(Category.from, Category);
  },
  addItemsToCategories(categories){
    return categories.map(this.addItemToCategory, this); // acá no se bien cómo hacer esto, quizá en dos pasos
  },
  addItemToCategory(category){
    return category.addItem(Item.from(category.item));
  },
  addCategoriesToList(categories){
    return categories.reduce( (prev, act) => prev.addItem(act), CategoryList.from({}) )
  },
  listToHTML(categoryList){
    return categoryList.toHTML();
  },
  renderHTML(html){
    $(this.selector).html(html);
  }
};