Custom Validation Rule in Model

I didn't fully understand your problem.
You can override the validate() method of the model to include your library.
Or add a method with your library to the beforeInsert/udpate/delete events.

Hi,
Thanks for your response...

I was hoping to use the validation functionality in the model itself instead of the Controller. I have written some validation rules for controller but want to write and use some for use in the model along with those built-in validations (E.g., required|in_list etc).

How do I add a method from my library to the beforeInsert/udpate/delete events?

Thanks for your help.