John: Since v12 of 4D we had one form for all outputs. It used a listbox. We let users determine which column they would show or not. We also let the system administrator add new columns that were based on fields or formulas that they could make up.
When a user selected one of the formula based columns it worked just fine. It was slower than without it, but if one needs the information it saves time overall. Sincerely Jody Bevan > On Aug 30, 2016, at 18:18, John DeSoi <[email protected]> wrote: > > >> On Aug 30, 2016, at 3:48 PM, Alan Tilson <[email protected]> wrote: >> >> Most of the time there is a matching 4D table but there could also be times >> where all the data is coming from an external source, so I suppose I am >> talking about array based listboxes. > > It takes some work, but selection based listboxes work well for displaying > large result sets from external databases. I use this all the time with > Postgres. You need a "dummy" table to create a record selection with the > number of rows in the result set. A table with a single boolean field is all > you need. You can use the On Display Detail event to cache just a subset of > the data needed to display the visible rows. > > It would be really nice if array based listboxes supported formula columns > and the on Display Detail event. Then all you would need to do is create a > boolean array with the right size and manage data fetching for the visible > rows. > > John DeSoi, Ph.D. > > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > FAQ: http://lists.4d.com/faqnug.html > Archive: http://lists.4d.com/archives.html > Options: http://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:[email protected] > ********************************************************************** ********************************************************************** 4D Internet Users Group (4D iNUG) FAQ: http://lists.4d.com/faqnug.html Archive: http://lists.4d.com/archives.html Options: http://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
