How To Supress a Formula if Parameter IsNull 1

[WestView]

Hello All,

I've got a formula based on a user input parameter field array. I have placed this formula in the report footer so that it prints all the parameter values inputted by the user. However, the parameter field is optional. Therefore, if the user leaves the parameter value null, an error occurs when the formula field tries to count the number of elements in the array. My code is below.


numbervar counter1;
stringvar holder1;
counter1 := count({?parameterField}); .
while counter1 > 0 do
(holder1 := holder1 + {? parameterField }[counter1] + Chr(13);
counter1 := counter1 - 1);
holder1 [1 to (length(holder1)-1)]


How do I keep this from happening?

Any/all help will be greatly appreciated!!!

Thanks,

Tom

 

[IanWaterman]

Try adding a command telling formula how to resond to zero length

eg

counter1 := count({?parameterField});

If counter1 = 0 then "" else

while counter1 > 0 do
(holder1 := holder1 + {? parameterField }[counter1] + Chr(13);
counter1 := counter1 - 1);
holder1 [1 to (length(holder1)-1)]

Ian

 

[lbass]

I think you can use your original formula as long as you add a default value like "No Selection" as your topmost value when setting up your parameter. If the user doesn't add anything when asked to select a parameter value, this string will populate the formula.

-LB

 

[WestView]

LB,

That did the trick. Thanks!!!

Tom