title: Extend ActiveRecord method_missing
body: <p>I've been looking around the web and have found a great deal of information on attempting what I am, however one bit of sugar I'd like to add to my Ruby/Rails mixin, is creating a function that looks for a pattern. I want to create a base function called</p>
  
  <p>is_a_*</p>
  
  <p>where * can be anything. Whatever that * is, needs to be retrievable so I can use it inside the function and act accordingly. Do I have to use method_missing?</p>