How to empty/clear cart when adding a new product?

Question

Is there any way to empty or clear the cart when a user adds a new product?

I'm aware of the clear_cart tag but this doesn't work when using the browser's back button, allowing users to add multiple products (or multiple types of products) to the cart.

I think this is happening because the page does not fully reload when using the back button so the clear_cart tag is not fired.

Expresso Store has a empty_cart parameter for it's product tag that empties the cart when a product is added as opposed to when the page loads.

I was wondering if there was anything similar for Cartthrob? Or a workaround that achieves the same thing?

I've thought about forcing the page to reload when using the back button but I'd prefer to avoid this if possible.

Answer 1

On clicking the add to cart button you could make an ajax GET request for a template that only contains the clear_cart tag... Although if it were me I'd probably build a quick extension to do this instead so it's not reliant on JavaScript. Would be very quick and easy using the cartthrob_add_to_cart_start hook: https://www.cartthrob.com/docs/developers/hooks/index.html#cartthrob_add_to_cart_start

Answer 2

(I'm with Vector; we make CartThrob)

Your "add to cart" link on product pages doesn't need to be a real "add to cart" link. When someone clicks "add to cart" on a product, they can be sent to a template like /store/add_to_cart/{product_id}. Then in your store/add_to_cart template you'd have something like:

{exp:cartthrob:clear_cart}
{exp:cartthrob:add_to_cart entry_id="{segment_3}" quantity="1" return="cart/index"}

ExpressionEngine should parse the clear_cart first, then the add_to_cart, and then redirect the user.