In starting this page, I do not know who is going to be interested so I do not know at what level to aim the notes. If you want more enlightenment on any hint, please contact me.
4QD use Pipedream to run our whole manufacturing and sales system. The whole suite of custom functions and command files is enormous but there are several interesting tips. The first is the custom function we use to allocate the next sale number. A number gets allocated as soon as a customer's name gets added to the list.
This method means that new lines can be inserted at any time simply by copying a live line into the end of the file. The custom function called by the example always looks at the last line above it in the sheet and allocates the next unused number.
Pipedream does not include a facility to single step through a command file, but you can do it very easily using StrongEd or Zap.
Load the command file into a StrongEd window, them mark a line (triple click in StrongEd) and drag it and drop it onto the PipeDream file it's meant to work on.
Of course you don't need to drop single lines, you can mark a block of as many lines as you want to test and drag that!
Several times I have needed to keep a list of serial numbers, where the number is of the form 00005 or B0102. This custom function takes such a text string and returns the same trxt string with the lzst digit incremented by one.
It is fairly crude and works for numbers such as B002, 0003 but not for B5 006 (space in string) or x5-001 (- in string).
This page's URL: http://www.4qd.co.uk/ro/pd4/wish.html