Ruby on Rails: how to get error messages from a child resource displayed?

Question

I\'m having a difficult time understanding how to get Rails to show an explicit error message for a child resource that is failing validation when I render an XML template.

Answer 1

I'm not sure if this is the best (or a correct) answer...i'm still learning, but I found this to work pretty well. I haven't tested it extensively, but it does seem to work with rails4:

validate do |school|
  school.errors.delete(:students)
  school.students.each do |student|
    next if student.valid?
    school.errors.add(:students, student.errors)
  end
end