CerealPagination: Demeter's Revenge for will_paginate.

cereal_pagination.rb

# CerealPagination: Demeter's Revenge for will_paginate.
# 
# For every has_many :foos association, creates a paginate_foos
# method which calls foos.paginate.
# 
# TODO: Support has_and_belongs_to_many.

module CerealPagination
  def self.included(base)
    base.instance_eval do
      class << self
        def has_many_with_cereal_pagination(association_name, *args)
          has_many_without_cereal_pagination(association_name, *args)
          define_method("paginate_#{association_name}") do |*args|
            send(association_name).paginate(*args)
          end
        end
        alias_method_chain(:has_many, :cereal_pagination)
      end
    end
  end
end

cereal_pagination_spec.rb

require File.dirname(__FILE__) + '/../spec_helper'

describe "A model with CerealPagination" do
  class ActiveRecordStub
    def self.has_many(name, *args); end
  end
  
  before(:each) do
    @klass = Class.new ActiveRecordStub
    @klass.send :include, CerealPagination
  end
  
  it "should have a paginate_foo method for each has_many association" do
    @klass.send :has_many, :johnson_rods
    
    object                 = @klass.new
    johnson_rods           = mock("johnson rods")
    paginated_johnson_rods = mock("paginated johnson rods")
    
    object.stub!(:johnson_rods).and_return(johnson_rods)
    johnson_rods.stub!(:paginate).and_return(paginated_johnson_rods)
    
    object.paginate_johnson_rods.should == paginated_johnson_rods
  end
end

include_cereal_pagination.rb

# Put this in your config/initializers to use CerealPagination in all your models.

class ActiveRecord::Base
  include CerealPagination
end