Hello,
We have a scenario where we have a drop down with an Other option, if the user selects Other they need to enter in a value into a text box. As this text box will only be used if Other is selected this means we need an expression to check for empty values and for this we are using ISNULL. The button to move to the next step is disabled until a value is entered.
What we are seeing is if a user enters a value the button is enabled, however if they then remove the value in the text box the button is still enabled. This can lead to a user saving empty values when they are required. Can Tulip look to change this behaviour? This has high impact from a data integrity perspective.
Users are smart! They figure out a way to get beyond a blocker to get to the next step!
Your request is valid and noted. I will track this and keep you posted.
Nawaz
The reason is, that an empty string is not null.
First the value is null, then you type something and remove it with backspace. Now you have an empty string, which is not the same as null.
Simply check for an expresion like LEN(@Variables.my_input_variable) >0 (or > whatever makes sense for the value) 
Or use an Input validity check.
I get the confusion, but somehow it is expected behavior. Better add a check for “blank” then changing the behavior of ISNULL().
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@clark_john_david any thoughts on the recommendation - “Simply check for an expression like LEN(@Variables.my_input_variable) >0..."
cc @sslavens
Many thanks, we are going to use this expression: ISNULL(Variables.(Input) Text) to (LEN(Variables.(Input) Text)=0)
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