Question

I have a class that I am using a the validates method to check for length, and I want to inject the actual length into the error message. Is this possible?

Here is my current class where I am using the validation:

class Something
  validates :summary, :detail, :length => { 
    :in => 300..500,
    :too_short => "must have at least %{count} letters",
    :too_long => "must have at most %{count} letters"
  }

And the error message shows:

2 errors prohibited this job from being saved.

Summary must have at least 300 letters
Detail must have at least 300 letters

But I’d like to show:

...
Summary is only 250 letters and must have at least 300 letters
...

Answer 1

for your solution, you can pass custom validation

validate:summary_length

def summary_length 
  if self.summary.length < 10 && !self.summary.blank?
    errors[:base] << "is only #{self.summary.size} letters and must have at least 10 letters"
  end
end