Schedule node revisions

Problem/Motivation

Imagine a situation where you have a constantly changing station schedule, with scheduled items being added or removed every other week. Though, you would like the website to be able to display the schedule of the station, on a particular date in the past.

Normally, the drupal node structure allows for node revisions, which are actually different historical states of the same node (like it happens with wikis). In the case of the schedule, one would expect the schedule node to be able to get a new revision, every time one or more schedule items change.

Unfortunately this is not the case. Schedule items always point to the initial node id and not the node revision id. So, according to the current implementation, there is no clean way for somebody to store the changes of a schedule, in one particular node structure.

Of course there are workarounds for this. E.g. one could create a new schedule, every time there are substantial changes and attach this to the same station, then set the new schedule as default. Although things become complicated, when somebody wants to know the exact days a schedule used to be active (can be done e.g. by adding a date CCK field to the schedule node).

Proposed resolution(s)

The quickest solution would be to change the schedule item entry, in order to point to the revision id, and then modify the schedule display queries accordingly.

The cleanest solution would be to re-implement the schedule items as node CCK (multi-)fields, attached to the schedule node. This way, revision creation and display would be handled automatically through the CCK mechanism. Although this would also require manipulation of all the functions that use/process schedule items...