Check the minimum and maximum length for individual cases at a time

Question

I check a surname field like this

validates :surname, :presence => true, :length => { :within => min_surname_length..max_surname_length, :message => "is bad (minimum is #{min_surname_length}, maximum is is #{max_surname_length})" } 

but I would like to separate cases where the minimum and maximum without a separate syntax check, like this

 validates_length_of :name, :minimum => 3 validates_length_of :name, :maximum => 30 

In a few words, I would like to do something like this (I know this is wrong):

  validates :surname, :presence => true, :length => { :within => min_surname_length..max_surname_length, :message => "is bad (minimum is #{min_surname_length}" IF MINIMUM, :message => "is bad (maximum is is #{max_surname_length})" IF MAXIMUM } 

How can this be done in one go?

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Decision

This is how I will use it:

 validates :surname, :length => { :within => min_password_length..max_password_length, :too_short => 'too short message', :too_long => 'too long message' } 

Answer 1

 validates_length_of :surname, :within => 3..30, :too_short => 'too short message', :too_long => 'too long message'