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pro_vb thread: Business Objects Framework Extension

Message #1 by "Mike Livenspargar" <MLIVENSP@s...> on Mon, 30 Apr 2001 11:09:40 -0700
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.

Mike Livenspargar

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