Setup
We have a multisite CiviCRM (Version 4.4.13) and the latest Drupal. CiviEvent is used to create events and manage participants. CiviCRM contacts and Drupal users are connected.
Each event has a custom contact reference field "Trainer". Admin staff will select the appropriate event's trainer (CiviCRM contact) in this field. Participants register via Drupal Webforms.
Aim
The aim is for every trainer to be able to see the names and certain registration information of his/her own training's participants (and only those). It should be accesible once the trainer logs in with his/her Drupal credentials.
Thoughts so far
One could probably use CiviCRM ACL feature. However, this would probably require to set up one ACL group per event - which is not feasible/comfortable as there are too many events.
We were considering a relationship created by the webform that grants the trainer permissions to view participants but wasn't able to come up with something viable either...
IMHO, most promising seems to be a Drupal View that shows the partcipants in question. However it would need some kind of filter or access restriction so that only the registration information of the trainer's participants is shown.
So far, I wasn't able to find a good solution. Maybe a contextual filter would work?
Question
Does anyone know, how to solve that in a Drupal View? Or of yourse any other approach which does not require a lot of manual work per event?
Any ideas or hints would be highly appreciated.