As noted in the Storefront guide, the shopping bag icon on the Store view will toggle the cart on and off. At the initial open of the application, this cart will be empty.
The cart ownership is by default a guest checkout, but a customer can be linked to the cart instead. Linking a customer means that the order being placed will be saved with their customer account and sync the account between the mobile device and the web. Unlinking a shopper from the cart will reset the cart, removing all items. On the other hand, linking a customer who has an existing cart in progress will fill in their current cart and selected items.
A customer can be linked by clicking the drop-down arrow menu in top right of the cart view and clicking Add Customer.
This will open a searchable list of customer accounts.
Once linked, their name will be visible at the top of the cart.
In the same way that a customer can be added to the cart, they can also be removed. Click the same drop-down icon again after a customer has been linked, and click Remove Customer.
Alternatively, swipe left on the customer's name in the cart view instead of clicking the drop-down and the option to remove them will be displayed as shown on the left.
Items can be added to a cart by clicking the Add to Cart button on the product description page. Additional quantities of the product may be added by pressing Add to Cart additional times or adjusting the quantity by incrementing or decrementing with the +/- buttons, or by entering a value in the number field.
The quantity can be adjusted after the product has been added to the cart as well:
Items may be removed by swiping on the item in the cart. This will bring up the option to remove the item from the cart. If an item has a quantity greater than 1, using this option will remove ALL quantities of the item from the current cart.
A cart with any products in it will show a running subtotal for the cart's value at checkout, pre-tax. This value updates whenever an item is added or removed. The cart also displays an itemized discount list for all of its contents.
A cart can have an order adjustment (price adjustment) manually applied to it, not exceeding the subtotal value of the cart. The adjustment value can be a set amount or percentage based. Note that this manual discount is removed when the cart's contents are updated, so it's recommended that any manual discount be applied as the last step of finalizing the cart for checkout.
If the shopper no longer wants their items or the checkout process needs to be paused, there are two additional options in the cart's dropdown menu alongside the Remove Customer option. Clicking Save Cart will save the current cart and allow the user to come back to it. Clicking Empty Cart will remove all items from the cart at once, more efficiently than swiping on each line item.