Data Validator Pattern error

Hello,

  I am building an API that used PUT method to update a set of JSON data into my taget database. One of the contents of the PUT method is a boolean type that would receive ether a "true" or "false" and is a mandatory entity.

I am using a Data Validator Snap with the "Pattern" constraint, but i am getting  the following error.

Below is the error, I am getting

Do i have to do any conversion of the incoming into a string? How do i resolve this issue?

Thanks

Aravind N