refs #47, #68, #74 generic pagination support for Array object

this enables you to paginate through any Arrayish object in this way:
  Kaminari.paginate_array(my_array_object).page(params[:page]).per(10)

lib/kaminari/models/array_extension.rb

@@ -0,0 +1,42 @@
+module Kaminari
+  # Kind of Array that can paginate
+  class PaginatableArray < Array
+    include Kaminari::ConfigurationMethods::ClassMethods
+
+    attr_internal_accessor :limit_value, :offset_value
+
+    def initialize(original_array, limit_val = default_per_page, offset_val = 0) #:nodoc:
+      @_original_array, @_limit_value, @_offset_value = original_array, limit_val, offset_val
+      super (original_array[offset_val, limit_val] || [])
+    end
+
+    # items at the specified "page"
+    def page(num = 1)
+      offset(limit_value * ([num.to_i, 1].max - 1))
+    end
+
+    # returns another chunk of the original array
+    def limit(num)
+      self.class.new @_original_array, num, offset_value
+    end
+
+    # total item numbers of the original array
+    def total_count
+      @_original_array.count
+    end
+
+    # returns another chunk of the original array
+    def offset(num)
+      arr = self.class.new @_original_array, limit_value, num
+      class << arr
+        include Kaminari::PageScopeMethods
+      end
+      arr
+    end
+  end
+
+  # Wrap an Array object to make it paginatable
+  def self.paginate_array(array)
+    PaginatableArray.new array
+  end
+end

lib/kaminari/railtie.rb

@@ -20,6 +20,7 @@ module Kaminari
         ::Mongoid::Document.send :include, Kaminari::MongoidExtension::Document
         ::Mongoid::Criteria.send :include, Kaminari::MongoidExtension::Criteria
       end
+      require File.join(File.dirname(__FILE__), 'models/array_extension')
       ActiveSupport.on_load(:action_view) do
         ::ActionView::Base.send :include, Kaminari::ActionViewExtension
       end

spec/models/array_spec.rb

@@ -0,0 +1,105 @@
+require File.expand_path('../spec_helper', File.dirname(__FILE__))
+
+describe Kaminari::PaginatableArray do
+  let(:array) { Kaminari::PaginatableArray.new((1..100).to_a) }
+  describe '#page' do
+    shared_examples_for 'the first page of array' do
+      it { should have(25).users }
+      its(:first) { should == 1 }
+    end
+
+    shared_examples_for 'blank array page' do
+      it { should have(0).items }
+    end
+
+    context 'page 1' do
+      subject { array.page 1 }
+      it_should_behave_like 'the first page of array'
+    end
+
+    context 'page 2' do
+      subject { array.page 2 }
+      it { should have(25).users }
+      its(:first) { should == 26 }
+    end
+
+    context 'page without an argument' do
+      subject { array.page }
+      it_should_behave_like 'the first page of array'
+    end
+
+    context 'page < 1' do
+      subject { array.page 0 }
+      it_should_behave_like 'the first page of array'
+    end
+
+    context 'page > max page' do
+      subject { array.page 5 }
+      it_should_behave_like 'blank array page'
+    end
+  end
+
+  describe '#per' do
+    context 'page 1 per 5' do
+      subject { array.page(1).per(5) }
+      it { should have(5).users }
+      its(:first) { should == 1 }
+    end
+  end
+
+  describe '#num_pages' do
+    context 'per 25 (default)' do
+      subject { array.page }
+      its(:num_pages) { should == 4 }
+    end
+
+    context 'per 7' do
+      subject { array.page(2).per(7) }
+      its(:num_pages) { should == 15 }
+    end
+
+    context 'per 65536' do
+      subject { array.page(50).per(65536) }
+      its(:num_pages) { should == 1 }
+    end
+
+    context 'per 0 (using default)' do
+      subject { array.page(50).per(0) }
+      its(:num_pages) { should == 4 }
+    end
+
+    context 'per -1 (using default)' do
+      subject { array.page(5).per(-1) }
+      its(:num_pages) { should == 4 }
+    end
+
+    context 'per "String value that can not be converted into Number" (using default)' do
+      subject { array.page(5).per('aho') }
+      its(:num_pages) { should == 4 }
+    end
+  end
+
+  describe '#current_page' do
+    context 'page 1' do
+      subject { array.page }
+      its(:current_page) { should == 1 }
+    end
+
+    context 'page 2' do
+      subject { array.page(2).per 3 }
+      its(:current_page) { should == 2 }
+    end
+  end
+
+  describe '#count' do
+    context 'page 1' do
+      subject { array.page }
+      its(:count) { should == 25 }
+    end
+
+    context 'page 2' do
+      subject { array.page 2 }
+      its(:count) { should == 25 }
+    end
+  end
+end