Capture Appian Default Validation

Question

Hi, 
 I have a link to be disabled depending on the values entered by the user. (Link should be disabled in case of any validation error). 
 I'm able to achieve the same for user-defined validations and not for Appian default ones. 
 For example, I have a date field. A user-defined validation appears if the user enters any previous date. The link could be disabled in this case. 
 On the contrary, consider the scenario where the user enters a text value into the date field, 
 
 an Appian default validation occur(as seen above). Is there any possible way to capture this so that i can disable the link based on that condition? Or is there any way to automatically nullify/empty the value when the user enters a text value into the date field? 
 PS: Appian Version used - 17.4 
 
 Regards, 
 Vaisakh Sekhar

Mike Schmitt · Answer

If you'll look at the actual saved value coming from the date field, I believe you'll find in your screenshot example that when the user types text into the date field, for example - no actual data is passed into your local / rule input variable. So in general we have no way of telling whether invalid data has been entered into a date field, however you should be able to design around the fact that the value will still be null in such a case.