Override ActiveRecord attribute methods

Require This picture Require This · Dec 17, 2008 · Viewed 66.3k times · Source

An example of what I'm talking about:

class Person < ActiveRecord::Base
  def name=(name)
    super(name.capitalize)
  end
  def name
    super().downcase  # not sure why you'd do this; this is just an example
  end
end

This seems to work, but I was just read the section on overriding attribute methods in the ActiveRecord::Base docs, and it suggests using the read_attribute and write_attribute methods. I thought there must be something wrong with what I'm doing in the example above; otherwise, why would they bless these methods as the "right way" to override attribute methods? They're also forcing a much uglier idiom, so there must be a good reason...

My real question: Is there something wrong with this example?

Answer

Aaron Longwell picture Aaron Longwell · Dec 18, 2008

Echoing Gareth's comments... your code will not work as written. It should be rewritten this way:

def name=(name)
  write_attribute(:name, name.capitalize)
end

def name
  read_attribute(:name).downcase  # No test for nil?
end