Question

In a RoR app, I want to specialize ActiveRecord’s update_attributes() method in one of my models, extracting some of the attributes for special handling and passing the rest of them to the original update_attributes() method. The details:

class Premise < ActiveRecord::Base
  ...
  def update_attributes(attrs)
    attrs.each_pair do |key, val|
      unless has_attribute?(key)
        do_special_processing(key, val)
        attrs.delete(key)
      end
    end
    # use original update_attributes() to process non-special pairs
    super.update_attributes(attrs)
  end
  ...
end

The call to super.update_attributes(attr) raises an error:

undefined method `update_attributes' for true:TrueClass

… which makes me suspect I really don’t understand the super keyword in Ruby. What am I missing? Specifically, how do I call the original update_attributes() method?

Answer 1

You want:

super(attrs)

That will call the original method, passing attrs as an argument to it.

As it is now, you’re trying to call update_attributes on the “true” value returned by the original update_attributes.