validates :changeset, :presence => true, :associated => true
validates :author, :presence => true, :associated => true
validates :visible, :inclusion => [true, false]
+ validates :body, :format => /\A[^\x00-\x08\x0b-\x0c\x0e-\x1f\x7f\ufffe\uffff]*\z/
# Return the comment text
def body