Merge pull request #1 from khiav223577/feature/deep_pluck

deep pluck

deep_pluck.gemspec

@@ -33,5 +33,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "minitest", "~> 5.0"
 
   spec.add_dependency "rails", ">= 3"
+  spec.add_dependency "pluck_all", "~> 1.2.1"
 
 end

gemfiles/3.2.gemfile

@@ -3,11 +3,11 @@ source 'https://rubygems.org'
 # Specify your gem's dependencies in pluck_all.gemspec
 
 gem "activerecord", "~> 3.2"
+gem "pluck_all", "~> 1.2.1"
 
 group :test do
   gem "simplecov"
   gem "codeclimate-test-reporter", "~> 1.0.0"
-  gem 'carrierwave', '~> 0.11.0'
 end
 
 gemspec :path => "../"

gemfiles/4.2.gemfile

@@ -3,11 +3,11 @@ source 'https://rubygems.org'
 # Specify your gem's dependencies in pluck_all.gemspec
 
 gem "activerecord", "~> 4.2"
+gem "pluck_all", "~> 1.2.1"
 
 group :test do
   gem "simplecov"
   gem "codeclimate-test-reporter", "~> 1.0.0"
-  gem 'carrierwave', '~> 0.11.0'
 end
 
 gemspec :path => "../"

gemfiles/5.0.gemfile

@@ -3,11 +3,11 @@ source 'https://rubygems.org'
 # Specify your gem's dependencies in pluck_all.gemspec
 
 gem "activerecord", "~> 5.0"
+gem "pluck_all", "~> 1.2.1"
 
 group :test do
   gem "simplecov"
   gem "codeclimate-test-reporter", "~> 1.0.0"
-  gem 'carrierwave', '~> 0.11.0'
 end
 
 gemspec :path => "../"

lib/deep_pluck.rb

@@ -1,2 +1,16 @@
 require "deep_pluck/version"
+require 'deep_pluck/model'
 require 'active_record'
+require 'pluck_all'
+
+class ActiveRecord::Relation
+  def deep_pluck(*args)
+    DeepPluck::Model.new(self).add(args).load_all
+  end
+end
+
+class ActiveRecord::Base
+  def self.deep_pluck(*args)
+    self.where('').deep_pluck(*args)
+  end
+end

lib/deep_pluck/model.rb

@@ -0,0 +1,95 @@
+module DeepPluck
+  class Model
+  #---------------------------------------
+  #  Initialize
+  #---------------------------------------
+    def initialize(relation, parent_association_key = nil, parent_model = nil)
+      @relation = relation
+      @parent_association_key = parent_association_key
+      @parent_model = parent_model
+      @need_columns = []
+      @associations = {}
+    end
+  #---------------------------------------
+  #  Reader
+  #---------------------------------------
+    def reflect_on_association(association_key)
+      @relation.klass.reflect_on_association(association_key)
+    end
+    def get_foreign_key(association_key, reverse = false)
+      reflect = reflect_on_association(association_key)
+      return (reflect.belongs_to? ? 'id' : reflect.foreign_key) if reverse
+      return (reflect.belongs_to? ? reflect.foreign_key : 'id')
+    end
+  #---------------------------------------
+  #  Contruction OPs
+  #---------------------------------------
+  private
+    def add_need_column(column)
+      @need_columns << column.to_s
+    end
+    def add_association(hash)
+      hash.each do |key, value|
+        model = (@associations[key] ||= Model.new(reflect_on_association(key).klass.where(''), key, self))
+        model.add(value)
+      end
+    end
+  public
+    def add(args)
+      return self if args == nil
+      args = [args] if not args.is_a?(Array)
+      args.each do |arg|
+        case arg
+        when Hash ; add_association(arg)
+        else      ; add_need_column(arg)
+        end
+      end
+      return self
+    end
+  #---------------------------------------
+  #  Load
+  #---------------------------------------
+  private
+    def set_includes_data(parent, children_store_name, model, order_by = nil)
+      reflect = reflect_on_association(children_store_name)
+      if reflect.belongs_to? #Child.where(:id => parent.pluck(:child_id))
+        children = model.load_data{|relaction| relaction.where(:id => parent.map{|s| s[reflect.foreign_key]}.uniq.compact).order(order_by) }
+        children_hash = Hash[children.map{|s| [s["id"], s]}]
+        parent.each{|s|
+          next if (id = s[reflect.foreign_key]) == nil
+          s[children_store_name] = children_hash[id]
+        }
+      else       #Child.where(:parent_id => parent.pluck(:id))
+        parent.each{|s| s[children_store_name] = [] }
+        parent_hash = Hash[parent.map{|s| [s["id"], s]}]
+        children = model.load_data{|relaction| relaction.where(reflect.foreign_key => parent.map{|s| s["id"]}.uniq.compact).order(order_by) }
+        children.each{|s|
+          next if (id = s[reflect.foreign_key]) == nil
+          parent_hash[id][children_store_name] << s
+        }
+      end
+      return children
+    end
+  public
+    def load_data
+      prev_need_columns = @parent_model.get_foreign_key(@parent_association_key, true) if @parent_model
+      next_need_columns = @associations.map{|key, _| get_foreign_key(key) }.uniq
+      all_need_columns = [*prev_need_columns, *next_need_columns, *@need_columns].uniq
+      @extra_columns = all_need_columns - @need_columns
+      @relation = yield(@relation) if block_given?
+      return (@data = @relation.pluck_all(*all_need_columns))
+    end
+    def load_all
+      data = load_data
+      @associations.each do |key, model|
+        set_includes_data(data, key, model)
+      end
+      delete_extra_column_data!
+      return data
+    end
+    def delete_extra_column_data!
+      @data.each{|s| s.except!(*@extra_columns) } if @data
+      @associations.each{|_, model| model.delete_extra_column_data! }
+    end
+  end
+end

test/deep_pluck_test.rb

@@ -4,8 +4,34 @@ class DeepPluckTest < Minitest::Test
   def setup
 
   end
+
   def test_that_it_has_a_version_number
     refute_nil ::DeepPluck::VERSION
   end
 
+  def test_pluck_with_1_level_deep
+    assert_equal [
+      {'name' => 'John'},
+      {'name' => 'Pearl'},
+    ], User.where(:name => %w(John Pearl)).deep_pluck(:name)
+  end
+
+  def test_pluck_with_2_level_deep
+    assert_equal [
+      {'name' => 'Pearl'    , :posts => [{'name' => "post4"}, {'name' => "post5"}]},
+      {'name' => 'Kathenrie', :posts => [{'name' => "post6"}]},
+    ], User.where(:name => %w(Pearl Kathenrie)).deep_pluck(:name, :posts => [:name])
+    assert_equal [
+      {'name' => 'John' , :contact => [{'address' => "John's Home"}]},
+      {'name' => 'Pearl', :contact => [{'address' => "Pearl's Home"}]},
+    ], User.where(:name => %w(John Pearl)).deep_pluck(:name, :contact => [:address])
+  end
+
+  def test_pluck_with_2_level_deep_and_reverse_association
+    assert_equal [
+      {'name' => 'post4', :user => {'name' => "Pearl"}},
+      {'name' => 'post5', :user => {'name' => "Pearl"}},
+      {'name' => 'post6', :user => {'name' => "Kathenrie"}},
+    ], Post.where(:name => %w(post4 post5 post6)).deep_pluck(:name, :user => [:name])
+  end
 end

test/seeds.rb

@@ -13,14 +13,23 @@
     t.string :name
     t.string :title
   end
+  create_table :contacts, :force => true do |t|
+    t.integer :user_id
+    t.string :address
+    t.string :phone_number
+  end
 end
 class User < ActiveRecord::Base
   serialize :serialized_attribute, Hash
   has_many :posts
+  has_one :contact
 end
 class Post < ActiveRecord::Base
   belongs_to :user
 end
+class Contact < ActiveRecord::Base
+  belongs_to :user
+end
 users = User.create([
   {:name => 'John', :email => 'john@example.com'},
   {:name => 'Pearl', :email => 'pearl@example.com', :serialized_attribute => {:testing => true, :deep => {:deep => :deep}}},
@@ -36,3 +45,8 @@ class Post < ActiveRecord::Base
   {:name => 'post5', :title => "Pearl's post2", :user_id => users[1].id},
   {:name => 'post6', :title => "Kathenrie's post1", :user_id => users[2].id},
 ])
+Contact.create([
+  {:address => "John's Home", :phone_number => "0911666888", :user_id => users[0].id},
+  {:address => "Pearl's Home", :phone_number => "1011-0404-934", :user_id => users[1].id},
+  {:address => "Kathenrie's Home", :phone_number => "02-254421", :user_id => users[2].id},
+])