Question

I have an object that contains a number range and a description [min_val, max_val, name].
I need to validate that min_val < max_val. However, if one of them is blank I get a nil comparison error, instead, I’d like to tell the user that a number is required.

Also, how can I change the error message for numericality?

validates :min_val, :presence => true, :numericality => {:greater_than => 0, :less_than => :max_val}

validates :max_val, :presence => true, :numericality => {:greater_than => 0, :greater_than => :min_val}

validates :name, :presence => true, :if => Proc.new { |r| !r.min_val.nil? || !r.max_val.nil? }

Answer 1

You can use :message to specify a custom error message.

validates :max_val, :presence => true, :numericality => {:greater_than => 0, :message => " is an invalid number."}
validates :min_val, :presence => true, :numericality => {:greater_than => 0, :message => " is an invalid number."}
validate do |record|
  record.errors.add_to_base("The min_val should be less than max_val") if min_val.to_i >= max_val.to_i
end
validates :name, :presence => true, :if => Proc.new { |r| !r.min_val.nil? || !r.max_val.nil? }