- basic dm pagination working

kaminari.gemspec

@@ -26,6 +26,10 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'sqlite3', ['>= 0']
   s.add_development_dependency 'mongoid', ['>= 2']
   s.add_development_dependency 'mongo_mapper', ['>= 0.9']
+  s.add_development_dependency 'dm-core', ['>= 1.1.0']
+  s.add_development_dependency 'dm-migrations', ['>= 1.1.0']
+  s.add_development_dependency 'dm-aggregates', ['>= 1.1.0']
+  s.add_development_dependency 'dm-sqlite-adapter', ['>= 1.1.0']
   s.add_development_dependency 'rspec', ['>= 0']
   s.add_development_dependency 'rspec-rails', ['>= 0']
   s.add_development_dependency 'rr', ['>= 0']

lib/kaminari/models/data_mapper_extension.rb

@@ -0,0 +1,67 @@
+
+module Kaminari
+  module DataMapperExtension
+    
+    #
+    module PageScopeMethods
+      include ::Kaminari::PageScopeMethods::InstanceMethods
+      
+      # Specify the <tt>per_page</tt> value for the preceding <tt>page</tt> scope
+      #   Model.page(3).per(10)
+      def per(num)
+        num = num.to_i
+        if num <= 0
+          self
+        else
+          #col = model.all(query.options.except(:limit,:offset).merge(:limit => num, :offset => offset_value / limit_value * num))
+          col = model.all(query.options.merge(:limit => num, :offset => offset_value / limit_value * num))
+          col.send :extend, PageScopeMethods
+          col
+        end
+      end
+      
+      def limit_value
+        query.limit
+      end
+      
+      def offset_value
+        query.offset
+      end
+      
+      def total_count
+        model.count(query.options.except(:limit,:offset,:order))
+      end
+      
+      def all(options={})
+        col = super(options)
+        col.send :extend, PageScopeMethods
+        col
+      end
+    end
+    
+    #
+    module Paginatable
+	  def page(num)
+	    num = [num.to_i, 1].max - 1
+        collection = all(:limit => default_per_page, :offset => default_per_page * num)
+        collection.send :extend, PageScopeMethods
+        collection
+      end
+    end
+    
+    
+    # This should be included into DataMapper::Collection.
+    # MyModel.all.class #=> DataMapper::Collection
+    module CollectionInstanceMethods
+      include Paginatable
+    end
+    
+    # This should be included into DataMapper::Model so that one can call:
+    # MyModel.page #=> DataMapper::Collection
+    module ModelClassMethods
+      include Paginatable
+      include Kaminari::ConfigurationMethods::ClassMethods
+    end
+    
+  end
+end

lib/kaminari/railtie.rb

@@ -2,6 +2,7 @@ require 'rails'
 # ensure ORMs are loaded *before* initializing Kaminari
 begin; require 'mongoid'; rescue LoadError; end
 begin; require 'mongo_mapper'; rescue LoadError; end
+begin; require 'dm-core'; require 'dm-aggregates'; rescue LoadError; end
 
 require File.join(File.dirname(__FILE__), 'config')
 require File.join(File.dirname(__FILE__), 'helpers/action_view_extension')
@@ -27,6 +28,10 @@ module Kaminari
         ::Plucky::Query.send :include, Kaminari::PluckyCriteriaMethods
         ::Plucky::Query.send :include, Kaminari::PageScopeMethods
       end
+      if defined? ::DataMapper
+        require File.join(File.dirname(__FILE__), 'models/data_mapper_extension')
+        ::DataMapper::Collection.send :include, Kaminari::DataMapperExtension::CollectionInstanceMethods
+      end
       require File.join(File.dirname(__FILE__), 'models/array_extension')
       ActiveSupport.on_load(:action_view) do
         ::ActionView::Base.send :include, Kaminari::ActionViewExtension

spec/models/data_mapper_spec.rb

@@ -0,0 +1,211 @@
+require File.expand_path('../spec_helper', File.dirname(__FILE__))
+require 'dm-core'
+require 'dm-migrations'
+require 'dm-aggregates'
+require File.expand_path('../../lib/kaminari/models/data_mapper_extension', File.dirname(__FILE__))
+
+describe Kaminari::DataMapperExtension do
+  before :all do
+    
+    DataMapper.setup(:default, 'sqlite::memory:')
+    
+    class Worker
+      include ::DataMapper::Resource
+      
+      property :id, Serial
+      property :name, String, :required => true
+      property :age, Integer, :required => true
+      
+      has n, :projects, :through => Resource
+    end
+    
+    class Project
+      include ::DataMapper::Resource
+      
+      property :id, Serial
+      property :name, String, :required => true
+      
+      has n, :workers, :through => Resource
+    end
+    
+    DataMapper.finalize
+    DataMapper.auto_migrate!
+    
+    ::DataMapper::Model.append_extensions Kaminari::DataMapperExtension::ModelClassMethods
+    
+    300.times do |i|
+      Worker.create(:name => "Worker#{i}", :age => i)
+    end
+    
+    worker0 = Worker[0]
+    50.times do |i|
+      worker0.projects << Project.create(:name => "Project#{i}")
+    end
+    worker0.projects.save
+    
+  end
+  
+  describe Kaminari::DataMapperExtension::PageScopeMethods do
+    context 'has methods' do
+		subject{ Kaminari::DataMapperExtension::PageScopeMethods.instance_methods }
+		it { should include(:per) }
+		it { should include(:current_page) }
+		it { should include(:num_pages) }
+		it { should include(:limit_value) }
+		it { should include(:offset_value) }
+		it { should include(:total_count) }
+    end
+  end
+  
+  #describe Kaminari::DataMapperExtension::Paginatable do
+  #  context 'has methods' do
+  #    subject{ Kaminari::DataMapperExtension::Paginatable.instance_methods }
+  #    it { should include(:page) }
+  #  end
+  #end
+  
+  #shared_examples_for Kaminari::DataMapperExtension::Paginatable do
+  #  context 'has methods' do
+  #    subject{ Kaminari::DataMapperExtension::Paginatable.instance_methods }
+  #    it { should include(:page) }
+  #  end
+  #end
+  
+  #describe Kaminari::DataMapperExtension::CollectionInstanceMethods do
+  #  it_behaves_like Kaminari::DataMapperExtension::Paginatable
+  #end
+  
+  #describe Kaminari::DataMapperExtension::ModelClassMethods do
+  #  it_behaves_like Kaminari::DataMapperExtension::Paginatable
+  #end
+  
+  describe 'Collection' do
+    subject{ Worker.all }
+    it { should respond_to(:page) }
+    it { should_not respond_to(:per) }
+  end
+  
+  describe 'Model' do
+    subject{ Worker }
+    it { should respond_to(:page) }
+    it { should respond_to(:default_per_page) }
+    it { should_not respond_to(:per) }
+  end
+
+  describe '#page' do
+    context 'page 0' do
+      subject { Worker.all(:age.gte => 200).page 0 }
+      its(:current_page) { should == 1 }
+      its('query.limit') { should == 25 }
+      its('query.offset') { should == 0 }
+      its(:total_count) { should == Worker.count(:age.gte => 200) }
+      its(:num_pages) { should == 4 }
+    end
+    
+    context 'page 1' do
+      subject { Worker.all(:age.gte => 0).page 1 }
+      its(:current_page) { should == 1 }
+      its('query.limit') { should == 25 }
+      its('query.offset') { should == 0 }
+      its(:total_count) { should == 300 }
+      its(:num_pages) { should == 12 }
+    end
+
+    context 'page 2' do
+      subject { Worker.page 2 }
+      its(:current_page) { should == 2 }
+      its('query.limit') { should == 25 }
+      its('query.offset') { should == 25 }
+      its(:total_count) { should == 300 }
+      its(:num_pages) { should == 12 }
+    end
+
+    context 'page "foobar"' do
+      subject { Worker.page 'foobar' }
+      its(:current_page) { should == 1 }
+      its('query.limit') { should == 25 }
+      its('query.offset') { should == 0 }
+      its(:total_count) { should == 300 }
+      its(:num_pages) { should == 12 }
+    end
+
+    context 'with criteria before' do
+      subject { Worker.all(:age.gt => 100).page 2 }
+      #its('query.conditions') { should == {:age.gt => 1} }
+      its(:current_page) { should == 2 }
+      its('query.limit') { should == 25 }
+      its('query.offset') { should == 25 }
+      its(:total_count) { should == Worker.count(:age.gt => 100) }
+      its(:num_pages) { should == 8 }
+    end
+
+    context 'with criteria after' do
+      subject { Worker.page(2).all(:age.gt => 100) }
+      #its('query.conditions') { should == {:age.gt => 100} }
+      its(:current_page) { should == 2 }
+      its('query.limit') { should == 25 }
+      its('query.offset') { should == 25 }
+      its(:total_count) { should == Worker.count(:age.gt => 100) }
+      its(:num_pages) { should == 8 }
+    end
+
+  end
+
+  describe '#per' do
+    context 'on simple query' do
+		subject { Worker.page(2).per(10) }
+		its(:current_page) { should == 2 }
+		its('query.limit') { should == 10 }
+		its('query.offset') { should == 10 }
+		its(:total_count) { should == 300 }
+		its(:num_pages) { should == 30 }
+    end
+    
+    context 'on query with condition' do
+      subject { Worker.page(5).all(:age.lte => 100).per(13) }
+      its(:current_page) { should == 5 }
+      its('query.limit') { should == 13 }
+      its('query.offset') { should == 52 }
+      its(:total_count) { should == 101 }
+      its(:num_pages) { should == 8 }
+    end
+    
+    context 'on query with order' do
+      subject { Worker.page(5).all(:age.lte => 100, :order => [:age.asc]).per(13) }
+      its(:current_page) { should == 5 }
+      its('query.limit') { should == 13 }
+      its('query.offset') { should == 52 }
+      its(:total_count) { should == 101 }
+      its(:num_pages) { should == 8 }
+    end
+    
+    context 'on chained queries' do
+      subject { Worker.all(:age.gte => 50).page(3).all(:age.lte => 100).per(13) }
+      its(:current_page) { should == 3 }
+      its('query.limit') { should == 13 }
+      its('query.offset') { should == 26 }
+      its(:total_count) { should == 51 }
+      its(:num_pages) { should == 4 }
+    end
+    
+    context 'on query on association' do
+      subject { Worker[0].projects.page(3).all(:name.like => 'Project%').per(5) }
+      its(:current_page) { should == 3 }
+      its('query.limit') { should == 5 }
+      its('query.offset') { should == 10 }
+      its(:total_count) { should == 50 }
+      its(:num_pages) { should == 10 }
+    end
+    
+    context 'on query with association conditions' do
+      subject { Worker.page(3).all(:projects => Project.all).per(5) }
+      its(:current_page) { should == 3 }
+      its('query.limit') { should == 5 }
+      its('query.offset') { should == 10 }
+      its(:total_count) { should == 50 }
+      its(:num_pages) { should == 10 }
+    end
+  end
+
+
+end

spec/spec_helper.rb

@@ -2,6 +2,7 @@ $LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 $LOAD_PATH.unshift(File.dirname(__FILE__))
 require 'rails'
 require 'mongoid'
+require 'dm-core'
 require 'kaminari'
 require 'database_cleaner'
 # Ensure we use 'syck' instead of 'psych' in 1.9.2