Simple Javascript Shopping Cart (Free Code Download)

Welcome to a tutorial on how to create a simple vanilla Javascript Shopping Cart. Looking to build an eCommerce website or web app? Not too keen on the complicated bloated scripts and just need a simple interface? Well, here it is. A standalone local storage shopping cart that does not use any frameworks – Read on to find out!

ⓘ I have included a zip file with all the example source code at the start of this tutorial, so you don’t have to copy-paste everything… Or if you just want to dive straight in.

 

 

TABLE OF CONTENTS

 

 

QUICK NOTES

For you guys who just want to use this as a “plugin”:

• Edit products.js, fill in your own products.
• Put the product images in the images/ folder.
• Set iURL in cart.js section A to an absolute URL if you have trouble with the images.
• Launch cart.html, use http:// not file://.
• Lastly, complete your own checkout sequence cart.js, section H.

If you spot a bug, feel free to comment below. I try to answer short questions too, but it is one person versus the entire world… If you need answers urgently, please check out my list of websites to get help with programming.

 

SCREENSHOT

 

EXAMPLE CODE DOWNLOAD

Click here to download the source code, I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

 

 

 

PART 1) THE HTML

<!-- (A) CART -->
<div id="cart-wrap">
  <!-- (A1) PRODUCTS LIST -->
  <div id="cart-products"></div>
 
  <!-- (A2) CURRENT CART ITEMS -->
  <div id="cart-items"></div>
</div>
 
<!-- (B) TEMPLATES -->
<!-- (B1) PRODUCT CELL -->
<template id="template-product">
<div class="p-item">
  <img class="p-img">
  <div class="p-info">
    <div class="p-txt">
      <div class="p-name"></div>
      <div class="p-price"></div>
    </div>
    <button class="cart p-add">+</button>
  </div>
</div>
</template>
 
<!-- (B2) CART ITEMS -->
<template id="template-cart">
<div class="c-item">
  <input class="c-qty" type="number" min="0">
  <div class="c-name"></div>
  <button class="c-del cart">X</button>
</div>
</template>
<template id="template-cart-checkout">
<div class="c-go">
  <button class="c-empty cart" onclick="cart.nuke()">Empty</button>
  <button class="c-checkout cart" onclick="cart.checkout()">Checkout</button>
</div>
</template>

1. The HTML interface should be very straightforward with only 2 sections in the <div id="cart-wrap"> container:
   • <div id="cart-products"> To contain the list of products.
   • <div id="cart-items"> To show the current items in the cart.
2. HTML templates for the product and cart items.

 

PART 2) THE PRODUCTS

// DUMMY PRODUCTS (PRODUCT ID : DATA)
var products = {
  123: {
    name : "iPon Min",
    img : "JS-CART-1.png",
    price : 123
  },
  124: {
    name : "iPon Pro Max Plus",
    img : "JS-CART-2.png",
    price : 1234
  }
};

Since we don’t have a database here, the only option is to hardcode all the products in a script.

 

 

PART 3) THE JAVASCRIPT

3A) THE PROPERTIES

var cart = {
  // (A) PROPERTIES
  hPdt : null,      // html products list
  hItems : null,    // html current cart
  items : {},       // current items in cart
  iURL : "images/", // product image url folder
  currency : "$",   // currency symbol
  total : 0,        // total amount
};

Captain Obvious – The var cart object will keep all the cart-related mechanics. Right at the top, we have a couple of properties.

• cart.hPdt and cart.hItems shouldn’t be too difficult to understand – We will use these to refer to <div id="cart-products"> and <div id="cart-items">.
• cart.items contains the current items in the cart. This is simply an object that has the format of PRODUCT ID : QUANTITY.
• iURL is the URL to the product image folder.
• currency and total The currency symbol and the total amount of items in the cart.

 

3B) WORKING WITH LOCALSTORAGE

// (B) LOCALSTORAGE CART
// (B1) SAVE CURRENT CART INTO LOCALSTORAGE
save : () => localStorage.setItem("cart", JSON.stringify(cart.items)),

// (B2) LOAD CART FROM LOCALSTORAGE
load : () => {
  cart.items = localStorage.getItem("cart");
  if (cart.items == null) { cart.items = {}; }
  else { cart.items = JSON.parse(cart.items); }
},
  
// (B3) NUKE CART!
nuke : () => { if (confirm("Empty cart?")) {
  cart.items = {};
  localStorage.removeItem("cart");
  cart.list();
}}

That’s right. Without a server session, whatever is in the cart will disappear as soon as the user reloads the page. To prevent that from happening, we will save the cart items into the localStorage.

• cart.save() simply saves cart.items into the local storage.
• cart.load() will fetch the data from the local storage and restore cart.items.
• Lastly, cart.nuke() will empty the entire cart.

 

 

3C) SHOPPING CART INITIALIZATION

// (C) INITIALIZE
init : () => {
  // (C1) GET HTML ELEMENTS
  cart.hPdt = document.getElementById("cart-products");
  cart.hItems = document.getElementById("cart-items");
    
  // (C2) DRAW PRODUCTS LIST
  cart.hPdt.innerHTML = "";
  let template = document.getElementById("template-product").content, p, item;
  for (let id in cart.products) {
    p = cart.products[id];
    item = template.cloneNode(true);
    item.querySelector(".p-img").src = cart.iURL + p.img;
    item.querySelector(".p-name").textContent = p.name;
    item.querySelector(".p-price").textContent = cart.currency + p.price.toFixed(2);
    item.querySelector(".p-add").onclick = () => cart.add(id);
    cart.hPdt.appendChild(item);
  }
    
  // (C3) LOAD CART FROM PREVIOUS SESSION
  cart.load();
    
  // (C4) LIST CURRENT CART ITEMS
  cart.list();
}

The init() function runs on page load. It may seem to be massive, but what it does is actually very basic:

• (C1) “Tie” cart.hPdt to <div id="cart-products"> and cart.hItems to <div id="cart-items">.
• (C2) Draw the list of products.
• (C3) Load the cart from the previous session.
• (C4) Draw the current cart items.

 

 

3D) DRAW SHOPPING CART ITEMS

// (D) LIST CURRENT CART ITEMS (IN HTML)
list : () => {
  // (D1) RESET
  cart.total = 0;
  cart.hItems.innerHTML = "";
  let item, empty = true;
  for (let key in cart.items) {
    if (cart.items.hasOwnProperty(key)) { empty = false; break; }
  }

  // (D2) CART IS EMPTY
  if (empty) {
    item = document.createElement("div");
    item.innerHTML = "Cart is empty";
    cart.hItems.appendChild(item);
  }
    
  // (D3) CART IS NOT EMPTY - LIST ITEMS
  else {
    let template = document.getElementById("template-cart").content, p;
    for (let id in cart.items) {
      p = cart.products[id];
      item = template.cloneNode(true);
      item.querySelector(".c-del").onclick = () => cart.remove(id);
      item.querySelector(".c-name").textContent = p.name;
      item.querySelector(".c-qty").value = cart.items[id];
      item.querySelector(".c-qty").onchange = function () { cart.change(id, this.value); };
      cart.hItems.appendChild(item);
      cart.total += cart.items[id] * p.price;
    }

    // (D3-3) TOTAL AMOUNT
    item = document.createElement("div");
    item.className = "c-total";
    item.id = "c-total";
    item.innerHTML = `TOTAL: ${cart.currency}${cart.total}`;
    cart.hItems.appendChild(item);
 
    // (D3-4) EMPTY & CHECKOUT
    item = document.getElementById("template-cart-checkout").content.cloneNode(true);
    cart.hItems.appendChild(item);
  }
}

The list() function draws the current cart items into <div id="cart-items">. Looks complicated, but it is just generating a whole load of HTML.

 

 

3E) SHOPPING CART ACTIONS

// (E) ADD ITEM INTO CART
add : id => {
  if (cart.items[id] == undefined) { cart.items[id] = 1; }
  else { cart.items[id]++; }
  cart.save(); cart.list();
},

// (F) CHANGE QUANTITY
change : (pid, qty) => {
  // (F1) REMOVE ITEM
  if (qty <= 0) {
    delete cart.items[pid];
    cart.save(); cart.list();
  }

  // (F2) UPDATE TOTAL ONLY
  else {
    cart.items[pid] = qty;
    var total = 0;
    for (let id in cart.items) {
      cart.total += cart.items[id] * products[id].price;
      document.getElementById("c-total").innerHTML = `TOTAL: ${cart.currency}${cart.total}`;
    }
  }
},
  
// (G) REMOVE ITEM FROM CART
remove : id => {
  delete cart.items[id];
  cart.save();
  cart.list();
},
  
// (H) CHECKOUT
checkout : () => {
  // SEND DATA TO SERVER
  // CHECKS
  // SEND AN EMAIL
  // RECORD TO DATABASE
  // PAYMENT
  // WHATEVER IS REQUIRED
  alert("TO DO");

  /*
  var data = new FormData();
  data.append("cart", JSON.stringify(cart.items));
  data.append("products", JSON.stringify(products));
  data.append("total", cart.total);
 
  fetch("SERVER-SCRIPT", { method:"POST", body:data })
  .then(res=>res.text())
  .then(res => console.log(res))
  .catch(err => console.error(err));
  */
}

Finally, all of these functions deal with cart actions:

• cart.add() Adds a selected item into the cart. Remember the format of cart.items = { ID : QUANTITY }? That is exactly what we are doing here.
• cart.change() Changes the quantity of the item in the cart.
• cart.remove() Removes an item from the cart.
• cart.checkout() Is up to you to complete – Send the order via email, SMS, save to database, save to Google Forms, etc…

 

 

MULTIPLE PRODUCT CATEGORIES?

As you may have noticed, there are no product categories. But yes, it is possible to add sections with some changes:

• Create another var categories object to hold the product IDs of each category. For example { CATEGORY-A: [123, 124, 125], CATEGORY-B: [1, 2, 3] }.
• Modify the cart.draw() function to draw the products in a selected category.

 

PRODUCT OPTIONS

For the guys who are sarcastically saying “adding product options should be easy for you, it can be done in 5 minutes” – Of course, it is “so simple”, even you can do it within “just a few minutes”. Feel free to challenge yourself:

• Create a new var options = { color : [red, green, blue], size : [small, large], ... }.
• Attach the options to products.
• Change the product list to also draw the options.
• Change the way the cart records items – PRODUCT-ID[OPTION][VALUE][OPTION][VALUE] : QUANTITY.

Yes, that’s all, just a few steps only. Please don’t ask about product options again… It is “so simple” that I don’t even want to touch on it.

 

A WAY BETTER SHOPPING CART

A shopping cart with product options, categories, discount coupons, user system, admin panel, API, and an installable web app - Click here to check out my eBook!

 

HOW TO “COMPLETE THE CHECKOUT”

The only piece of advice I can give is to learn a server-side programming language of your choice – PHP, ASP, JSP, Python, or NodeJS. Everyone has different requirements.

• Save order to the database.
• Save order to Google Forms.
• Send order via email.
• Send order via SMS.
• Process online payment.
• Link up with other systems.

As you can guess, there is simply no way that I can explain “how to checkout” in every possible scenario and language. Neither can I give free consultation services. So it is up to you to complete your own checkout sequence. If you need more examples, check out the PHP MySQL shopping cart link below… Or get my eBook above. 😆

 

COMPATIBILITY CHECKS

• Local Storage – CanIUse
• Arrow Function – CanIUse

Works well in all modern browsers. If you want to be safe, use Modernizr to do feature checks and even load polyfills.

 

LINKS & REFERENCES

• Need a more “substantial” cart? Check out my PHP MySQL Shopping Cart tutorial.
• Shopping Cart Design Ideas – SpeckyBoy
• Javascript POS System – Code Boxx
• Javascript Food Ordering System – Code Boxx
• Example on CodePen – JS Shopping Cart