Yes i added validation function(included in my question).
I am trying to fill the phone_no slot using "phone_no":self.from_text(intent="phone_no"), if change this to "phone_no":self.from_text(intent=None) it works fine. ie, it fille the phone_no slot with user input and execute the validate_ function.
Edit: Now i have the same issue with slot email. Current slot mapping is "email":self.from_text(intent="email") and if i modify this to "email":self.from_text(intent=None) and a validate_ function, it will work fine.
So then what is the use of other functions in Custom slot Mapping.
And what is the use of regex in nlu.md. because i already defined a regex and i need to define avalidate funciton to check the same regex!!!
Please suggest any solution…