Do not allow whitespace only in textfield validation

Question

I have a textField that I do not want users to be able to enter in a space unless it is a part of the case number. 
 For example, users should not be able to enter this: 
 
 But if there are spaces in the case number, then it should be allowed

I've tried regexmatch, I've tried a if / isnullorempty statement 
 example: 
 if(
 a!isNullOrEmpty(ri!notice),
 "Case Number is invalid.",
 null()
)

Mike Schmitt · Answer

trim your input at save time. 
 a!textField(
 label: "notice",
 value: ri!notice,
 saveInto: a!save(ri!notice, trim(save!value))
)

Mike Schmitt · Answer

You can only display an error message when a string is entered. So you can choose either to trim the input (thus not allowing only blank space to be entered), or you can use a validation that shows up when removing all blanks would result in a null. 
 validations: { if( a!isNullOrEmpty(trim(ri!notice)), "don't enter only blank spaces", null() ) }

Shubham Aware · Answer

You try this below code a!localVariables(
 local!caseNumber,
 a!textField(
 label: "Case Number",
 labelPosition: "ABOVE",
 saveInto: local!caseNumber,
 placeholder: "Enter Case Number",
 refreshAfter: "UNFOCUS",
 value: local!caseNumber,
 validations: {
 if(
 or(
 a!isNullOrEmpty(local!caseNumber),
 len(trim(local!caseNumber)) = 0
 ),
 "Case Number is invalid.",
 null()
 )
 }
 )
)

Mike Schmitt · Answer

Just an FYI - while this won't cause an error or anything, the null check in the validation message here is not useful, as all field validations (i.e. things in the "validations" parameter, as opposed to "required" validations which are configured separately) do not fire under any circumstances when the field's value is null. Hence the validation configuration I already suggested above.