Question

I’m having this in my model.
However, the model is used as polymorphic and I want to have different condition.
How can I do code if I’m doing this in controller?

models/comment.rb

validates_length_of :body, 
                    :within => 10..100, 
                    :message => "must be between 10 to 100 characters"

UPDATE:

I only want to use this validation condition when Community model is creating a comment into comment model.
Comment model is polymorphic!
It has commentable_type and commentable_id

Answer 1

No you cann’t do anything like this in controller.
Use condition in your model or put this in community model.

validates_length_of :body, 
                    :within => 10..100, 
                    :message => "must be between 10 to 100 characters", :if => "community?"

  def community?
    return self.commentable_type == "Community"
  end