Use unique user id in url segment

Question

I have a simple page with a simple PayPal Buy button on the page. When a person buys an item, and completes the purchase on PayPal, they will be returned to a thank-you page.

In order to NOT have people access the thank-you page if they have not actually purchased anything, I would like to give every user a unique ID in the return url and use it as a url_segment.

When the user returns, the url will look like www.domain.com/thank-you/34567654
In the template I could do something like:

{if current_id != segment_2}
  {redirect='/'}
{/if}

Does something like this exist?

I know how to pass the option in the PayPal return url, but can one generate a unique user id (session id) and compare it like in my example. Use it as a template var?

Answer 1

My approach would be to use Stash.

On the checkout page:

{exp:stash:set_value
    name="checking_out" {!-- User is checking out --}
    value="1"           {!-- Store any value --}
    scope="user"        {!-- Limit this to the user's session --}
    save="yes"          {!-- Store in the database --}
    refresh="10"        {!-- Only valid for 10 minutes --}
}

Then check against this being stored on the thank you page:

{if {exp:stash:not_empty name="checking_out" scope="user"}}
    {redirect='/'}
{/if}