Just a quick post on an error I ran into today while using hidden fields:
undefined method `merge' for 5:Fixnum 27:28: 'button' %> 29:30: 31: 32:
Thankfully this is an easy fix, simply amend your code as follows:
'button' %>@upload.product_id %>
And that’s all there is to it, let me know if there are any issues.