Add "Cart URL" API

[JustinSainton]

wpsc_get_add_to_cart_url should create a custom URL that will redirect a user to a cart, filled with items passed to the URL.

Now, originally, I was thinking about just a query string of the cart items, passed to the add_to_cart handler. But this can be problematic on some nginx configurations, and many Apache configurations if the query string is greater than 4,000 characters.

What might make sense is that the it generates a a hash that corresponds to a saved array that is then posted as a cart, and the user is then redirected to the checkout page.

Need to do some more thinking on this, but I like the thought generally. And even without the API - as of 4a5c55b, this can be done via GET string.

Cart URLs like this can be used for Buy Now buttons, Buy Now buttons for packages of products, links to include in email campaigns - lots of great use cases.

[curtismchale]

So we're looking at something like:

function wpsc_add_to_cart_hash_rule() {
    add_rewrite_rule( '^wpsc-cart_url/([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})/?', 'index.php?wpsc-cart-hash=$matches[1]', 'top' );
}
add_action( 'init', 'wpsc_add_to_cart_hash_rule' );

Then we'd save the hash and product ids that go with it when the user would click the button and match it at the cart and populate the cart.

Probably not useful to keep the store of this hash/product_ids around after added to cart.

Store as a no load option.

[JustinSainton]

That's pretty much what I'm thinking 👍

[JustinSainton]

I would imagine some kind of WPSC_Cart_URL class. Within that class, you'd want to probably implement a UUID generation method, as PHP does not have a native one, but you could borrow a couple methods from this class