Forum OpenACS Development: error raised when activity appears in several role-parts

I am testing the imsld package with some of the learning designs found on http://moodle.learningnetworks.org/ in the "Runnable LD Example Units of Learning" node. When I tried http://hdl.handle.net/1820/316, I realized following problem:

When an activity is referenced in several role-parts, following error is raised, upon access to a resource.

Database operation "0or1row" failed (exception NSINT, "Query returned more than one row.")

SQL:
select item_id as rp_item_id, role_part_id
from imsld_role_partsi
where activity_structure_id = '3854'

The solution probably consists in passing also the act where the activity appears to the get_role_part_from_activity function. Unless, you return all role_parts where the activity is referenced, and mark them finished. But this would mean that the activity gets marked as finished for all plays where it appears.

This raises a more general question I wanted to ask you: In the design of the imsld package, I could not find the concept of a "run" that instantiates a learning design, and that would make it possible to restart the delivery from scratch with a new run if desired. Is this something you plan to add?

I am wondering if you do not need the concept of a "run" if you deal with multi-user learning_designs where you "enroll" users to a unit of learning, assign them to roles, before you start delivering it, and have to keep track of them as the community of users participating in the same "run", as suggested in the "Implementation guide" of the specification.

Regards,

Michael,

We are right now working on supporting multiple runs for the same UoL. So the first thing the professor will have to do after uploading an UoL is to assign users to the run. Then the roles instances, properties instances, etc. will refer to the run (instance of the UoL).

More specifically, I was thinking about adding a "imsld_runs" table, which will map the run with the ims_ld_id. Then the instance of the roles will be made with the users which are assigned to the run, and the "status" table will also store the run_id. Also, the properties instances will refer This way there may be multiple runs for the same UoL.

Do you have any comments?

Sorry, I forgot to react to the first point. I am not sure if marking the activity finished for all role parts where it is referenced, is what is intended by the specification.
If you think of a learning design with two plays, which both reference the same activity, but in two different contexts. If a user first executes play 1, and passes the activity, and later he executes play 2. When it comes to the activity he already has passed in play 1, it could possibly make a different sense in the new context, and if it had been already marked as finished, the flow of play 2 could become disturbed, or in the first case no longer make sense.
Does this make sense?