Product:
Planning Analytics 2.0.9.18
Microsoft Windows 2019 server

Issue:
In a TI process check that the parameter is not empty?

Solution:

If the parameter is pFirst then enter code like this in prolog:

IF ( ~( pFirst @= '' ) ) ;

    ProcessQuit ;
ENDIF;

ProcessQuit will stop the process totally,  itemreject will go to the next tab and process that – if run from prolog. In MetaData and Data tab the itemreject will act different.

# sErrorMessage = ‘The ‘ | pFirst | ‘ is not empty’;
# ItemReject ( sErrorMessage );

More Information:

 https://www.tm1forum.com/viewtopic.php?t=8074

https://exploringtm1.com/operators-tm1-ti-if-statements/ 

https://exploringtm1.com/operators-tm1-rule-statements/

https://www.wimgielis.com/tm1_ifstructures_EN.htm 

https://exploringtm1.com/itemreject-tm1-function-syntax-use/

https://www.ibm.com/docs/en/planning-analytics/2.0.0?topic=pctf-itemreject