To turn on and require validation rules for a form field, please go to Actions >> Validation Options:




Enable validation here:




Validation Rules:


  • Min/Max Characters


Restricts how many characters a field can have.

On the right side, the error message can be added. 





It will look like this in the front end:



  • Numerical Value Range


Set numerical range this field's value needs to fall within.





It will look like this in the front end:




  • Regular Expression


This is an advanced setting for developers to input REGEX rules.




So for example, the regex that is in the placeholder above:

 

/^[a-zA-Z0-9_.]+$

 

It means that the content has to be any combination of lowercase or uppercase letters (A - Z), numbers, underscores, and periods. 

No other characters would be accepted. Use without the leading or trailing slash /. 


NOTE: If no error message is added, the system will show general error messages. These messages are text labels and are edited by going to Settings >> Text Labels. 


Then at the right top in the search bar, please type "Form validation" and all labels related to these messages will show up.