Grant CCK Field edit rights to a user referenced from User Reference; Drupal

Question

In Drupal I am trying to create a content node where the original author can upload an image and then 'challenge' another user to upload an image into that node as well. I can already grant the 2nd user access rights through CCK > User Reference > Node Access User Reference but I don't want that new user to be able to edit the whole node, only 1 imageFile field. Is there any way to do this Grant Per User Field Access User Reference?

Answer 1

Try http://drupal.org/project/field_permissions (in addition to what you have done above)

Using above module, deny edit access to all fields that are not created by author. But allow edit (regardless of author) access to the imagefield.

Edit: [Probably doesn't apply] If this doesn't work it might help to install a helper module called module grants (http://drupal.org/project/module_grants). It ANDs access allow/deny between modules that deal with permissions instead of OR. See http://drupal.org/node/408816#appendix Though I suspect this doesn't apply cause one module is dealing with Node permissions and other with field permissions.