Cognos RS - Issue with using Trim with ParamValue

[vvasireddy9]

Hi

I have a requirement where when user leaves a text box prompt empty or mistakenly enters spaces, a column in the result list should be hidden. To achieve this, I created the below conditional variable:

(trim(ParamValue('AcctName')) is null)

I need to use trim because the condition should succeed even when the user puts a space in the text box prompt. when I add the trim function the report is throwing a 'Invalid expression' error.

Any ideas or workarounds?

Thanks
VJ

[BigChris]

Hi VJ - I might be barking up the wrong tree, but I think you need to change "...is null" to be "...is missing". Of course it depends on what platform you're using etc.

[Lynn]

When you are dealing with variables you are dealing with report expressions, not database expressions.

Take a look at what the syntax information is for trim in the report expression dialog.

trim ( trim_what_expression , match_character_expression , string_expression )
Returns "string_expression" trimmed of any leading and trailing blanks or trimmed of the character specified by "match_character_expression". "Trim_what_expression" may be "leading", "trailing", or "both" (default). "Match_character_expression" can be an empty string to trim blanks or can specify a character to be trimmed.

Personally I'd use a Boolean render variable for the job so that the column only renders when a value is provided. I'd also use character length to avoid the whole issue with "null" vs '' for empty string vs "is missing". But then that's just a preference. There are lots of ways to tackle that logic.

Code Select Expand


character_length ( trim( 'both', '', ParamValue('AcctName') ) ) > 0


[vvasireddy9]

Thanks Lynn! Appreciate it..

I should have looked at the information window for 'Tips' in the first place.

[Lynn]

Thanks Lynn! Appreciate it..

I should have looked at the information window for 'Tips' in the first place.

I only know because I made the same mistake in the past! Very easy to overlook.