For the Cedar Falls Poker website, there's a stats page in which a particular model is hit pretty hard. There used to be a series of methods handling the retrieval of data in a useful manner, but I standardized the way this happens so I could clean up the model code and make it more useful.

This uses Hashes to return data in a format that is easy to turn into pie charts or bar graphs. This code assumes a few things. It assumes you do not have any other methods with _data in the name. It assumes that you're only going to be pulling data that is available as a method or attribute call; namely, using send. If your classes aren't set up this way, they probably should be.

class << self
  def data(atr)
    returning(Hash.new(0)) do |h|
      all.each do |rec|
        h[rec.send(atr)] += 1
      end
    end
  end
 
  def method_missing(meth, *attrs)
    if meth.to_s.match(/(\w+)\_data/)
      data($1)
    end
  end
end

And, as an example of how you might use this:

# assume we have a 'Game' model with an attribute called 'kind' and an attribute called 'structure'
a = Game.structure_data # => calls data('structure')
b = Game.kind_data # => calls data('kind')
 
p a #=> { 'No Limit' => 5, 'Pot Limit' => 6, 'Tournament' => 2 }
p b #=> { 'Cash' => 11, 'Tournament' => 2 }

Rails does stuff like this a lot, but it's nice to see how simple it is to provide such flexible functionality. Note that if you are not using this in Rails, you might have to rewrite the data method to avoid using returning, and find an alternative to using 'all'.