Drupal 7 and 8 versions
These versions are under heavy development and are not intended for production use yet.
Drupal 8 - Dependencies
Instead of reinventing the wheel, on Drupal 8 version of this module, both validation and format are done by an external library. The library used is Nicebooks ISBN library.
This library is already included to be download if you download ISBN module via Composer like:
composer require drupal/isbn
Drupal 6 version
Additional CCK display plugin modules could be written.
- CCK (Content) Module (Drupal 6 only)
- OpenLibrary API (Drupal 6 only)