Мне нужно добавить своего рода проверку к моему javascript коду, который выдаст сообщение «Пожалуйста, выберите элемент перед нажатием на покупку. Я включил мой код скрипта html и java ниже. Как только пользователь нажмет» ладно, им придется go вернуться назад и выбрать элемент, а затем нажать «покупка».
<!DOCTYPE html>
<html>
<head>
<title>E-SHOP</title>
<meta name="description" content="description">
<link rel="stylesheet" href="style.css" />
<script src="java.js" async></script>
</head>
<body>
<header class="main-header">
<nav class="main-nav nav">
<ul>
<li><a href="sitemap.html">sitemap</a></li>
<li><a href="home.html">HOME</a></li>
<li><a href="distination.html">DESTINATION</a></li>
<li><a href="about.html">ABOUT US</a></li>
<li><a href="contactus.html">CONTACT US</a></li>
<li><a href="eshop.html">E-SHOP</a></li>
<a href="#"style="float:left">Love Travel</a>
</ul>
</nav>
<h1 class="band-name eshop-banner">E-SHOP</h1>
</header>
<section class="container content-section">
<h2 class="section-header">Travel items </h2>
<div class="shop-items">
<div class="shop-item">
<span class="shop-item-title">Black suitcase</span>
<img class="shop-item-image" src="Images/suitcase7.png">
<div class="shop-item-details">
<span class="shop-item-price">£54.99</span>
<button class="btn btn-primary shop-item-button" type="button">ADD TO CART</button>
</div>
</div>
<div class="shop-item">
<span class="shop-item-title">Red and black suitcase</span>
<img class="shop-item-image" src="Images/suitcase10.png">
<div class="shop-item-details">
<span class="shop-item-price">£54.99</span>
<button class="btn btn-primary shop-item-button"type="button">ADD TO CART</button>
</div>
</div>
<div class="shop-item">
<span class="shop-item-title">Yellow Backpack</span>
<img class="shop-item-image" src="Images/yellowbackpack.png">
<div class="shop-item-details">
<span class="shop-item-price">£49.99</span>
<button class="btn btn-primary shop-item-button" type="button">ADD TO CART</button>
</div>
</div>
<div class="shop-item">
<span class="shop-item-title">Rainbow Backpack</span>
<img class="shop-item-image" src="Images/rainbowbackpack.png">
<div class="shop-item-details">
<span class="shop-item-price">£49.99</span>
<button class="btn btn-primary shop-item-button" type="button">ADD TO CART</button>
</div>
</div>
</div>
<div class="shop-items">
<div class="shop-item">
<span class="shop-item-title">World T-Shirt</span>
<img class="shop-item-image" src="Images/shirt2.png">
<div class="shop-item-details">
<span class="shop-item-price">£19.99</span>
<button class="btn btn-primary shop-item-button" type="button">ADD TO CART</button>
</div>
</div>
<div class="shop-item">
<span class="shop-item-title">Portable travel mug</span>
<img class="shop-item-image" src="Images/travelmug.png">
<div class="shop-item-details">
<span class="shop-item-price">£14.99</span>
<button class="btn btn-primary shop-item-button" type="button">ADD TO CART</button>
</div>
</div>
</div>
</section>
<section class="container content-section">
<h2 class="section-header">CART</h2>
<div class="cart-row">
<span class="cart-item cart-header cart-column">ITEM</span>
<span class="cart-price cart-header cart-column">PRICE</span>
<span class="cart-quantity cart-header cart-column">QUANTITY</span>
</div>
<div class="cart-items">
</div>
<div class="cart-total">
<strong class="cart-total-title">Total</strong>
<span class="cart-total-price">£0</span>
</div>
<button class="btn btn-primary btn-purchase" type="button">PURCHASE</button>
</section>
</a>
</li>
</ul>
</div>
</footer>
</body>
</html>
Мой java код скипта начинается здесь, что в основном является проверкой. Это бит, который нужно изменить.
if (document.readyState == 'loading') {
document.addEventListener('DOMContentLoaded', ready)
} else {
ready()
}
function ready() {
var removeCartItemButtons = document.getElementsByClassName('btn-danger')
for (var i = 0; i < removeCartItemButtons.length; i++) {
var button = removeCartItemButtons[i]
button.addEventListener('click', removeCartItem)
}
var quantityInputs = document.getElementsByClassName('cart-quantity-input')
for (var i = 0; i < quantityInputs.length; i++) {
var input = quantityInputs[i]
input.addEventListener('change', quantityChanged)
}
var addToCartButtons = document.getElementsByClassName('shop-item-button')
for (var i = 0; i < addToCartButtons.length; i++) {
var button = addToCartButtons[i]
button.addEventListener('click', addToCartClicked)
}
document.getElementsByClassName('btn-purchase')[0].addEventListener('click', purchaseClicked)
}
function purchaseClicked() {
alert('Thank you for your purchase. You will receive your purchased items within 3 working days')
var cartItems = document.getElementsByClassName('cart-items')[0]
while (cartItems.hasChildNodes()) {
cartItems.removeChild(cartItems.firstChild)
}
updateCartTotal()
}
function removeCartItem(event) {
var buttonClicked = event.target
buttonClicked.parentElement.parentElement.remove()
updateCartTotal()
}
function quantityChanged(event) {
var input = event.target
if (isNaN(input.value) || input.value <= 0) {
input.value = 1
}
updateCartTotal()
}
function addToCartClicked(event) {
var button = event.target
var shopItem = button.parentElement.parentElement
var title = shopItem.getElementsByClassName('shop-item-title')[0].innerText
var price = shopItem.getElementsByClassName('shop-item-price')[0].innerText
var imageSrc = shopItem.getElementsByClassName('shop-item-image')[0].src
addItemToCart(title, price, imageSrc)
updateCartTotal()
}
function addItemToCart(title, price, imageSrc) {
var cartRow = document.createElement('div')
cartRow.classList.add('cart-row')
var cartItems = document.getElementsByClassName('cart-items')[0]
var cartItemNames = cartItems.getElementsByClassName('cart-item-title')
for (var i = 0; i < cartItemNames.length; i++) {
if (cartItemNames[i].innerText == title) {
alert('This item is already added to the cart')
return
}
}
var cartRowContents = `
<div class="cart-item cart-column">
<img class="cart-item-image" src="${imageSrc}" width="100" height="100">
<span class="cart-item-title">${title}</span>
</div>
<span class="cart-price cart-column">${price}</span>
<div class="cart-quantity cart-column">
<input class="cart-quantity-input" type="number" value="1">
<button class="btn btn-danger" type="button">REMOVE</button>
</div>`
cartRow.innerHTML = cartRowContents
cartItems.append(cartRow)
cartRow.getElementsByClassName('btn-danger')[0].addEventListener('click', removeCartItem)
cartRow.getElementsByClassName('cart-quantity-input')[0].addEventListener('change', quantityChanged)
}
function updateCartTotal() {
var cartItemContainer = document.getElementsByClassName('cart-items')[0]
var cartRows = cartItemContainer.getElementsByClassName('cart-row')
var total = 0
for (var i = 0; i < cartRows.length; i++) {
var cartRow = cartRows[i]
var priceElement = cartRow.getElementsByClassName('cart-price')[0]
var quantityElement = cartRow.getElementsByClassName('cart-quantity-input')[0]
var price = parseFloat(priceElement.innerText.replace('£', ''))
var quantity = quantityElement.value
total = total + (price * quantity)
}
total = Math.round(total * 100) / 100
document.getElementsByClassName('cart-total-price')[0].innerText = '£' + total;
}