Merge b2085a9 into 6621ab1

lib/lotus/model/adapters/memory/query.rb

@@ -58,6 +58,7 @@ def initialize(dataset, collection, &blk)
             @collection = collection
             @conditions = []
             @modifiers  = []
+            @associations = []
             instance_eval(&blk) if block_given?
           end
 
@@ -68,7 +69,7 @@ def initialize(dataset, collection, &blk)
           #
           # @since 0.1.0
           def all
-            @collection.deserialize(run)
+            @collection.deserialize(run, @associations)
           end
 
           # Adds a condition that behaves like SQL `WHERE`.
@@ -554,6 +555,41 @@ def group
             raise NotImplementedError
           end
 
+          # Preload a given association into root's aggregation
+          # This should be implemented inside Repository in a class method. See example below.
+          #
+          # @since x.x.x
+          # @return Lotus::Model::Adapters::Memory::Query
+          #
+          # @example
+          #
+          #     mapping do
+          #       collections :users do
+          #         entity User
+          #         attribute :id, Integer
+          #         association :articles, [Article], foreign_key: :user_id, collection: :articles
+          #       end
+          #
+          #       collections :articles do
+          #         entity Article
+          #         attribute :id, Integer
+          #         attribute :user_id, Integer
+          #         association :user, User, foreign_key: :id, collection: :articles
+          #       end
+          #     end
+          #
+          #      class UserRepository
+          #        include Lotus::Repository
+          #
+          #       def with_articles
+          #         query.preload(:articles)
+          #       end
+          #     end
+          def preload(association)
+            @associations << association
+            self
+          end
+
           protected
           def method_missing(m, *args, &blk)
             if @context.respond_to?(m)

lib/lotus/model/adapters/sql/collection.rb

@@ -13,20 +13,28 @@ module Sql
         # @see http://sequel.jeremyevans.net/rdoc/files/doc/dataset_basics_rdoc.html
         # @see http://sequel.jeremyevans.net/rdoc/files/doc/dataset_filtering_rdoc.html
         class Collection < SimpleDelegator
+          # @attr_reader associations [Array] symbols names to preload mapped collections
+          #
+          # @since x.x.x
+          # @api private
+          attr_reader :associations
+
           # Initialize a collection
           #
           # @param dataset [Sequel::Dataset] the dataset that maps a table or a
           #   subset of it.
           # @param mapped_collection [Lotus::Model::Mapping::Collection] a
           #   mapped collection
+          # @param associations [Array] association symbols names to preload
           #
           # @return [Lotus::Model::Adapters::Sql::Collection]
           #
           # @api private
           # @since 0.1.0
-          def initialize(dataset, mapped_collection)
+          def initialize(dataset, mapped_collection, associations = [])
             super(dataset)
             @mapped_collection = mapped_collection
+            @associations = associations
           end
 
           # Filters the current scope with an `exclude` directive.
@@ -41,7 +49,7 @@ def initialize(dataset, mapped_collection)
           # @api private
           # @since 0.1.0
           def exclude(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Creates a record for the given entity and assigns an id.
@@ -73,7 +81,7 @@ def insert(entity)
           # @api private
           # @since 0.1.0
           def limit(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Filters the current scope with an `offset` directive.
@@ -88,7 +96,7 @@ def limit(*args)
           # @api private
           # @since 0.1.0
           def offset(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Filters the current scope with an `or` directive.
@@ -103,7 +111,7 @@ def offset(*args)
           # @api private
           # @since 0.1.0
           def or(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Filters the current scope with an `order` directive.
@@ -118,7 +126,7 @@ def or(*args)
           # @api private
           # @since 0.1.0
           def order(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Filters the current scope with an `order` directive.
@@ -133,7 +141,7 @@ def order(*args)
           # @api private
           # @since 0.1.0
           def order_more(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Filters the current scope with a `select` directive.
@@ -149,15 +157,14 @@ def order_more(*args)
           # @since 0.1.0
           if RUBY_VERSION >= '2.1'
             def select(*args)
-              Collection.new(super, @mapped_collection)
+              Collection.new(super, @mapped_collection, @associations)
             end
           else
             def select(*args)
-              Collection.new(__getobj__.select(*Lotus::Utils::Kernel.Array(args)), @mapped_collection)
+              Collection.new(__getobj__.select(*Lotus::Utils::Kernel.Array(args)), @mapped_collection, @associations)
             end
           end
 
-
           # Filters the current scope with a `group` directive.
           #
           # @param args [Array] the array of arguments
@@ -170,7 +177,7 @@ def select(*args)
           # @api private
           # @since 0.5.0
           def group(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Filters the current scope with a `where` directive.
@@ -185,7 +192,7 @@ def group(*args)
           # @api private
           # @since 0.1.0
           def where(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Updates the record corresponding to the given entity.
@@ -211,7 +218,42 @@ def update(entity)
           # @api private
           # @since 0.1.0
           def to_a
-            @mapped_collection.deserialize(self)
+            @mapped_collection.deserialize(self, @associations)
+          end
+
+          # Preload a given association into root's aggregation
+          # This should be implemented inside Repository in a class method. See example below.
+          #
+          # @since x.x.x
+          # @return Lotus::Model::Adapters::Sql::Collection
+          #
+          # @example
+          #
+          #     mapping do
+          #       collections :users do
+          #         entity User
+          #         attribute :id, Integer
+          #         association :articles, [Article], foreign_key: :user_id, collection: :articles
+          #       end
+          #
+          #       collections :articles do
+          #         entity Article
+          #         attribute :id, Integer
+          #         attribute :user_id, Integer
+          #         association :user, User, foreign_key: :id, collection: :articles
+          #       end
+          #     end
+          #
+          #      class UserRepository
+          #        include Lotus::Repository
+          #
+          #       def with_articles
+          #         query.preload(:articles)
+          #       end
+          #     end
+          def preload(association)
+            @associations << association
+            self
           end
 
           # Select all attributes for current scope
@@ -224,7 +266,7 @@ def to_a
           #
           # @see http://www.rubydoc.info/github/jeremyevans/sequel/Sequel%2FDataset%3Aselect_all
           def select_all
-            Collection.new(super(table_name), @mapped_collection)
+            Collection.new(super(table_name), @mapped_collection, @associations)
           end
 
           # Use join table for current scope
@@ -237,7 +279,7 @@ def select_all
           #
           # @see http://www.rubydoc.info/github/jeremyevans/sequel/Sequel%2FDataset%3Ajoin_table
           def join_table(*args)
-            Collection.new(super, @mapped_collection)
+            Collection.new(super, @mapped_collection, @associations)
           end
 
           # Return table name mapped collection

lib/lotus/model/adapters/sql/query.rb

@@ -49,6 +49,12 @@ class Query
           # @api private
           attr_reader :conditions
 
+          # @attr_reader collection [Lotus::Model::Adapters::Sql::Collection]
+          #
+          # @since x.x.x
+          # @api private
+          attr_reader :collection
+
           # Initialize a query
           #
           # @param collection [Lotus::Model::Adapters::Sql::Collection] the
@@ -59,7 +65,8 @@ class Query
           #
           # @return [Lotus::Model::Adapters::Sql::Query]
           def initialize(collection, context = nil, &blk)
-            @collection, @context = collection, context
+            @collection = collection
+            @context = context
             @conditions = []
 
             instance_eval(&blk) if block_given?
@@ -596,6 +603,41 @@ def negate!
             end
           end
 
+          # Preload a given association into root's aggregation
+          # This should be implemented inside Repository in a class method. See example below.
+          #
+          # @since x.x.x
+          # @return Lotus::Model::Adapters::Sql::Query
+          #
+          # @example
+          #
+          #     mapping do
+          #       collections :users do
+          #         entity User
+          #         attribute :id, Integer
+          #         association :articles, [Article], foreign_key: :user_id, collection: :articles
+          #       end
+          #
+          #       collections :articles do
+          #         entity Article
+          #         attribute :id, Integer
+          #         attribute :user_id, Integer
+          #         association :user, [User], foreign_key: :id, collection: :articles
+          #       end
+          #     end
+          #
+          #      class UserRepository
+          #        include Lotus::Repository
+          #
+          #       def with_articles
+          #         query.preload(:articles)
+          #       end
+          #     end
+          def preload(association)
+            @collection.preload(association)
+            self
+          end
+
           # Apply all the conditions and returns a filtered collection.
           #
           # This operation is idempotent, and the returned result didn't
@@ -754,6 +796,9 @@ def _join(collection, options = {})
           #   # You're welcome ;)
           def apply(query)
             dup.tap do |result|
+              query.collection.associations.each do |association|
+                result.preload(association)
+              end
               result.conditions.push(*query.conditions)
             end
           end

lib/lotus/model/associations/many_to_one.rb

@@ -0,0 +1,53 @@
+module Lotus
+  module Model
+    module Associations
+      # Entities Association ManyToOne relationship
+      class ManyToOne
+        # @attr_reader related collection (the other side of relationship)
+        #
+        # @since x.x.x
+        attr_reader :collection
+
+        # @attr_reader Repository responsible will roots this association
+        #
+        # @since x.x.x
+        attr_accessor :repository
+
+        # Collects initial data to build ManyToOne Association
+        #
+        # @since x.x.x
+        #
+        # @example
+        #
+        #   collection: :articles, foreign_key: :article_id, repository: ArticlesRepository
+        def initialize(opts)
+          @name        = opts.fetch(:name)
+          @collection  = opts.fetch(:collection)
+          @foreign_key = opts.fetch(:foreign_key) {default_foreign_key}
+          @repository  = nil
+        end
+
+        # @since x.x.x
+        # @api private
+        def associate_entities!(entities)
+          entities.map do |entity|
+            entity.send("#{@name}=", @repository.find(entity.send(@foreign_key)))
+            entity
+          end
+        end
+
+        private
+        # Default Foreign key's name
+        #
+        # It's possible to overwrite this through foreign_key attribute
+        # inside mapping via association method.
+        #
+        # @api private
+        # @since x.x.x
+        def default_foreign_key
+          "#{@name}_id"
+        end
+      end
+    end
+  end
+end