[development] Module compatibility/interoperability problem

[Eric Schaefer]

Hi List,

the scheduler module uses date_popup for letting the user choose date
and time for scheduled publishing of nodes, if it is installed. This
causes a problem with the multistep module. With this module you can
divide the node form into multiple steps like a "node wizard".
date_popup transforms its two fields (date and time) into one field
during validation (?) since the date_popup widget is virtually one
field. If the scheduler field group is not part of the first multistep
step then there has not been any validation for the
scheduler/date_popup fields and therefore the publish_on field is
still an array of two (empty) values instead of a single value. This
confuses the schedulers validation logic, because it expects either an
empty string or a propperly formatted string but not an array. To fix
this I could check if it is an array and let it pass on validation.
That would be rather easy and straitforward. But I do not like the
idea of littering scheduler with code that circumvents problems with a
non-core module that is not even used by scheduler itself. This would
also introduce a nasty dependency on multisteps (form handling)
behaviour. That would be fine, if scheduler did actually use multistep
functionality (as it is using date_popups functionality), but it does
not. I do not like that and I don't think this is a good thing to do.

What do you think. What should I do? How can this problem be resolved
in a nice and clean way?

Regards,
Eric