[sqr-users] Dynamic Substitution Vars

[Matt Rogish <rogishmn@muohio.edu>]

All,

I sent a message earlier about dynamic 'input' variables and got some 
interesting suggestions on and off list, none of which worked out quite as 
I had hoped.

To re-cap:
We have lots of programs which have this basic structure:
set up variables
ask for input
run some SQL
show report
show summary

In order to ease maintenance what I'd like to do is standardize the "set up 
variables", "ask for input", and "show summary" pieces using some sort of 
dynamic SQR.

In the summary section we list some report variables (counters and things) 
and we like to list the input parameters because there's nothing like 
getting a complex multi-section report and trying to guess what input 
parameters the particular report was run with (because the user forgets, or 
you look at the report a month later, or they were in Brio Portal but have 
since been changed, etc.).

The way we have it now is something like this:
begin-procedure get-input
   Input $code 'Enter some code'
   Input $begin_date 'Enter report begin date' type=date
   ..
end-procedure

begin-procedure show-input-summary
   print 'Input Parameters:' (+1) bold

   print 'Some Code: ' (+2)
   print $code

   print 'Begin Date: ' (+2)
   print $begin_date

   etc.
end-procedure

Oftentimes there are many parameters so it becomes cumbersome to list long 
blocks of Input and print statements.  It also makes maintenance a 
nightmare because you don't know which programs require what input and if 
you want to change/add one you have to change it several places.

So, the goal is to minimize code changes when the input parameter list 
changes -- either by adding, changing, or removing input 
parameters.  Preferably, there would be one spot in the program where I 
change a parameter list and the get-input and show-input-summary procedures 
do not have to change!  It goes without saying that there might have to be 
other changes to handle the addition or removal of a parameter, but that 
can come later. :)

Some ideas I've considered are:
Idea One -- Build an array which stores the input parameter name 
("some_code") and input query string ("Enter some code") then loop through 
each one and build an 'Input' statement from this.
Problem:
I don't know how to execute dynamic SQR code, namely something like:
let $stmt = 'Input $' || $input_var_name || ' ''' || $input_query || ''''
[$stmt]
This gives an error:
(SQR 4008) Unknown function or variable in expression: [$stmt]

Idea Two -- Create substitution variables, loop through each of them, and 
use them in Input statements.
Problem:
I can't dynamically *name* a substitution variable:
Let #num = 1
#DEFINE variable_number_#1
Show {variable_number_1}
This gives an error:
(SQR 4707) No value found for substitution variable: {variable_number_1}

Any help/ideas?


Thanks,

--
Matt Rogish - rogishmn@muohio.edu 

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