cart-view.js

/*
Copyright 2018 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import View from 'view';
import {pushLocationHash} from 'url-tools';
import {findProduct} from 'products';

export default class CartView extends View {

  constructor(cart, containerId = 'cart') {
    super(containerId);
    this._cart = cart;
    this._element = 'tr';
    this._elementClass = 'product';
    this._clickHandler = null;
    this._tbody = this._container.querySelector('tbody');
    this._checkoutBtn = document.getElementById('checkoutBtn');
  }

  install() {
    this._clickHandler = this._handleClick.bind(this);
    this._container.addEventListener('click', this._clickHandler, true);
    // Checkout button switches hash to "pay", will cause the form to open
    this._checkoutBtn.addEventListener('click', this._goToPayment.bind(this));
  }

  render() {
    // Remove existing products
    let itemRows = this._tbody.querySelectorAll(this.itemSelector);
    for (let i = 0; i < itemRows.length; i++) {
      this._tbody.removeChild(itemRows[i]);
    }
    for (let item of this._cart.cart) {
      let product = findProduct(item.sku);
      let placeholder = document.createElement('tbody');
      placeholder.innerHTML = `<tr class="product" data-sku="${product.sku}">
        <td class="mdl-data-table__cell-non-numeric">${product.title}</td>
        <td>${item.quantity}</td>
        <td>$${product.price}</td>
        <td><button class="mdl-button mdl-button--colored mdl-js-button
              mdl-js-ripple-effect mdl-button--accent delete"
              data-sku="${product.sku}" data-action="remove">
              <i class="material-icons">delete</i>remove</button>
        </td>
      </tr>`;
      this._tbody.appendChild(placeholder.firstElementChild); // WARN: no ie8
    }
    // Add the total price
    this.updateTotal();
  }

  updateTotal() {
    document.getElementById('cart-total').innerText = `$${this._cart.total}`;
  }

  removeFromView(sku) {
    let row = this._tbody.querySelector(`tr[data-sku=${sku}]`);
    if (row) {
      row.parentNode.removeChild(row);
    }
    this.updateTotal();
  }

  _goToPayment() {
    pushLocationHash('pay');
  }

  _handleClick(event) {
    if (event.target.dataset) {
      const sku = event.target.dataset.sku;
      const action = event.target.dataset.action;
      if (sku && action == 'remove') {
        const product = this._cart.findItem(sku);
        this._cart.remove(product);
        this.removeFromView(sku);
      }
    }
  }

  // utility for unit testing (used in counting the number of elements)
  get itemSelector() {
    return `${this._element}.${this._elementClass}[data-sku]`;
  }

  set cart(cart) {
    this._cart = cart;
  }

}