I really like the n-tier framework Lhotka established in his business
objects books. I'd like to extend the framework and am looking for more
information and thoughts that will help me to do so.
Basically, I'd like to set up a "query by form" like what is available in
Microsoft Access. Rather than presenting the user with a list of matches
from which they can pick one to view/update, I'd like to allow them to
scroll through the set of all matches, viewing each item one at a time and
updating as necessary.
My current thought is to take the Customers object, for example, and turn
it into an ADO data source. I can then let ADO manage record navigation,
and indeed use bound controls to display the data, which seems simple to
me. I would create a new business object when a row becomes current, and
ApplyEdit when leaving the current row. Does this make sense? Is there a
better way to do this?
I'd also like to turn the business object itself into a data source and
use bound controls to display its data and the data for its children, for
instance displaying the children in a grid rather than a ListView. Is this
a foolish path? Should I resign myself to using a grid in unbound mode
instead? If I take this route, what are the ramifications in regard to the
parent/child interactions that Lhotka implements?
I can add the data source behavior to the business object classes without
changing their existing behavior, so this seems to me just another
interface to the business object.
Are there more books I should be reading?
I appreciate any comments you have in this regard. I have a very large
application running on big Unix boxes and I think it's time to update the
user interface. The business object model Lhotka presents looks very
promising (and indeed we've already implemented it to some extent) and
we'd like to make it a viable solution.