use-cart

A tiny react hook for creating a e-commerce cart in your app

Installation

Note: please ensure you install versions >= 16.8.0 for both react and react-dom, as this library depends on the new hooks feature

NPM

npm i use-cart --save

Yarn

yarn add use-cart

Quick Start

import { CartProvider, useCart } from "use-cart"

// Wrap your app to expose the store
const App = () => (
  <CartProvider>
    <>
      <Item />
      <Cart />
    </>
  </CartProvider>
)

// Add the hook in any child component to get access to functions
const Item = () => {
  const { addItem } = useCart()
  return (
    <div>
      <p>My item for sale</p>
      <button onClick={() => addItem("TEST_SKU")}>Add to basket</button>
    </div>
  )
}

// You can use the hook in as many components as you want and they all share the same cart state
const Cart = () => {
  const { items, addItem, removeItem, removeLineItem, clearCart } = useCart()

  return (
    <div>
      {items.map(item => (
        <div>
          {item.sku} - {item.quantity}{" "}
          <Button onClick={() => addItem(item.sku)}>Increase Quantity</Button>
          <Button onClick={() => removeItem(item.sku)}>
            Decrease Quantity
          </Button>
          <Button onClick={() => removeLineItem(item.sku)}>
            Remove from cart
          </Button>
        </div>
      ))}
      <Button onClick={clearCart}>Clear Cart</Button>
    </div>
  )
}

Examples

• Basic
• Using local storage to load a saved cart

API

<CartProvider>

Passes the cart object to the useCart hook

Props

initialCart (Array): initial state that the cart will contain on initial render, it must be an array of objects

children (React.ReactNode): react component, usually containing the rest of your app

useStore()

The main hook must be wrapped with the CartProvider component at some point in the ancestor tree

Returns

Object containing:

• addItem(sku, [quantity=1]): Function - takes a sku an optional quantity (defaults to 1) to add to the cart
• removeItem(sku, [quantity=1]): Function - removes an item from the cart defaults to a quantity of 1.
• removeLineItem(sku): Function - removes an entire line item from the cart
• clearCart(): Function - removes all items from the cart
• isInCart(sku): Function - returns true if sku is present in the cart otherwise false
• items: Array - array of objects containing a minimum of sku and quantity properties on each object
• lineItemsCount: Number - returns number of unique line items n the cart
• totalItemsCount: Number - returns number of all quantities of line items combined

Detailed API from useCart object

addItem(sku, [quantity=1])

This method adds an item to the cart identified by its sku, if you would like to add more quantity you can pass an optional quantity value.

Arguments

sku (String): The unique item sku that identifies the item in the cart

[quantity=1] (Number): The quantity added to the cart

Returns

(undefined)

removeItem(sku, [quantity=1])

Removes a quantity from an item in the cart if this number drops to 0 the line item is removed from the cart.

Arguments

sku (String): The unique item sku that identifies the item in the cart

[quantity=1] (Number): The quantity removed from the cart

Returns

(undefined)

removeLineItem(sku)

A convenience function that removes an entire line item from the cart. This would be the same thing as getting the quantity of a line item then calling removeItem() by that quantity.

Arguments

sku (String): The unique item sku that identifies the item in the cart

Returns

(undefined)

isInCart(sku)

Allows you to quickly check if a item with the given sku is present in the cart

Arguments

sku (String): The unique item sku that identifies the item in the cart

Returns

(boolean): Returns true if the sku exists in the cart

items

(array): An array containing objects with sku and quantity properties of each item in the cart.

lineItemsCount

(number): The number of unique skus in the cart

totalItemsCount

(number): The number of all the quantities from all the sku's in the cart