Date:         Fri, 21 Sep 2007 17:59:24 -0400
Reply-To:     Paul Walker <walker.627@OSU.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Paul Walker <walker.627@OSU.EDU>
Subject:      Application Design: Error Checking System

At various points throughout a SAS application, I would like to have a
series of "Error Checks" done.  For example, before the application runs
its 1st set of routines, I would like to check some basic information
about the inputs provided by the user, such as:

  * Existence of the dataset specified
  * Whether the dataset has any rows
  * Whether the dataset has all the variables needed
  * Whether the variables are of the correct length
  * Whether the variables are of the correct type
  * Etc.
  * Etc.

If the inputs fail on any of the checks, then subsequent steps in the
application will not execute.

To do the error checks, I am taking a "Table Driven Approach" where I have
a lookup table which lists the checks to be performed and the SAS program
to call to implement that check.  There is also a listing of dependency,
such as some checks won't run unless a certain other checks were passed
successfully.  It is eloquent but somewhat complicated.

So, my question is, do any SAS-L'ers have experience with designing error
checking systems?  Has anyone else tried a table driven approach?  Any
alternative approaches?  Any suggestions or things to watch out for?  Any
SUGI or other references you could provide on the topic?

TIA
- Paul