This is a significant update of the Payment API. The main features included in this version are:
- Support for Transaction States: Each transaction is always in a particular state, whether it's "Pending," "Active", "Completed" or "Canceled."
- Support for payment actions: The API now supports an extensible mechansim for defining and executing payment actions, such as 'authorize', 'complete', 'cancel' and 'delete'.
- Support for Drupal actions - the above-mentioned actions can be executed by Drupal through the Actions API or using the VBO module.
- Support for a sitewide currency selection. Please see #932666 for history and roadmap.
We've also fixed a lot of bugs, refactored some code, and added some refinements. Please give this release a try!