I have a set of relations that I would like to edit with rules. In particular, I'd like to add to the set of endpoints. I've attempted to fetch the endpoints of a relation, add to it, and then save back into the relation, but this hasn't worked. I've even tried creating a new relation with the updated list, and it didn't save.
I'm writing a module for Spreedly to work with Commerce 1 (Drupal 7) - technically a payments api that then lets you use and switch between over 100 payments gateways.
Having never done this before, I'm looking for a good (and simple) module to clone and adapt. Do you have any recommendations for which one to choose?