diff options
10 files changed, 220 insertions, 15 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb index 565ebf8197..812abf5a55 100644 --- a/activerecord/lib/active_record/associations.rb +++ b/activerecord/lib/active_record/associations.rb @@ -111,6 +111,7 @@ module ActiveRecord autoload :HasAndBelongsToManyAssociation, 'active_record/associations/has_and_belongs_to_many_association' autoload :HasManyAssociation, 'active_record/associations/has_many_association' autoload :HasManyThroughAssociation, 'active_record/associations/has_many_through_association' + autoload :NestedHasManyThroughAssociation, 'active_record/associations/nested_has_many_through_association' autoload :HasOneAssociation, 'active_record/associations/has_one_association' autoload :HasOneThroughAssociation, 'active_record/associations/has_one_through_association' diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb index 97883d8393..964c381c0d 100644 --- a/activerecord/lib/active_record/associations/has_many_through_association.rb +++ b/activerecord/lib/active_record/associations/has_many_through_association.rb @@ -1,4 +1,5 @@ require "active_record/associations/through_association_scope" +require "active_record/associations/nested_has_many_through" require 'active_support/core_ext/object/blank' module ActiveRecord @@ -6,6 +7,7 @@ module ActiveRecord module Associations class HasManyThroughAssociation < HasManyAssociation #:nodoc: include ThroughAssociationScope + include NestedHasManyThrough alias_method :new, :build diff --git a/activerecord/lib/active_record/associations/nested_has_many_through.rb b/activerecord/lib/active_record/associations/nested_has_many_through.rb new file mode 100644 index 0000000000..2d03b81128 --- /dev/null +++ b/activerecord/lib/active_record/associations/nested_has_many_through.rb @@ -0,0 +1,156 @@ +module ActiveRecord + module Associations + module NestedHasManyThrough + def self.included(klass) + klass.alias_method_chain :construct_conditions, :nesting + klass.alias_method_chain :construct_joins, :nesting + end + + def construct_joins_with_nesting(custom_joins = nil) + if nested? + @nested_join_attributes ||= construct_nested_join_attributes + "#{construct_nested_join_attributes[:joins]} #{@reflection.options[:joins]} #{custom_joins}" + else + construct_joins_without_nesting(custom_joins) + end + end + + def construct_conditions_with_nesting + if nested? + @nested_join_attributes ||= construct_nested_join_attributes + if @reflection.through_reflection && @reflection.through_reflection.macro == :belongs_to + "#{@nested_join_attributes[:remote_key]} = #{belongs_to_quoted_key} #{@nested_join_attributes[:conditions]}" + else + "#{@nested_join_attributes[:remote_key]} = #{@owner.quoted_id} #{@nested_join_attributes[:conditions]}" + end + else + construct_conditions_without_nesting + end + end + + protected + + # Given any belongs_to or has_many (including has_many :through) association, + # return the essential components of a join corresponding to that association, namely: + # + # * <tt>:joins</tt>: any additional joins required to get from the association's table + # (reflection.table_name) to the table that's actually joining to the active record's table + # * <tt>:remote_key</tt>: the name of the key in the join table (qualified by table name) which will join + # to a field of the active record's table + # * <tt>:local_key</tt>: the name of the key in the local table (not qualified by table name) which will + # take part in the join + # * <tt>:conditions</tt>: any additional conditions (e.g. filtering by type for a polymorphic association, + # or a :conditions clause explicitly given in the association), including a leading AND + def construct_nested_join_attributes(reflection = @reflection, association_class = reflection.klass, table_ids = {association_class.table_name => 1}) + if (reflection.macro == :has_many || reflection.macro == :has_one) && reflection.through_reflection + construct_has_many_through_attributes(reflection, table_ids) + else + construct_has_many_or_belongs_to_attributes(reflection, association_class, table_ids) + end + end + + def construct_has_many_through_attributes(reflection, table_ids) + # Construct the join components of the source association, so that we have a path from + # the eventual target table of the association up to the table named in :through, and + # all tables involved are allocated table IDs. + source_attrs = construct_nested_join_attributes(reflection.source_reflection, reflection.klass, table_ids) + + # Determine the alias of the :through table; this will be the last table assigned + # when constructing the source join components above. + through_table_alias = through_table_name = reflection.through_reflection.table_name + through_table_alias += "_#{table_ids[through_table_name]}" unless table_ids[through_table_name] == 1 + + # Construct the join components of the through association, so that we have a path to + # the active record's table. + through_attrs = construct_nested_join_attributes(reflection.through_reflection, reflection.through_reflection.klass, table_ids) + + # Any subsequent joins / filters on owner attributes will act on the through association, + # so that's what we return for the conditions/keys of the overall association. + conditions = through_attrs[:conditions] + conditions += " AND #{interpolate_sql(reflection.klass.send(:sanitize_sql, reflection.options[:conditions]))}" if reflection.options[:conditions] + + { + :joins => "%s INNER JOIN %s ON ( %s = %s.%s %s) %s %s" % [ + source_attrs[:joins], + through_table_name == through_table_alias ? through_table_name : "#{through_table_name} #{through_table_alias}", + source_attrs[:remote_key], + through_table_alias, source_attrs[:local_key], + source_attrs[:conditions], + through_attrs[:joins], + reflection.options[:joins] + ], + :remote_key => through_attrs[:remote_key], + :local_key => through_attrs[:local_key], + :conditions => conditions + } + end + + # reflection is not has_many :through; it's a standard has_many / belongs_to instead + # TODO: see if we can defer to rails code here a bit more + def construct_has_many_or_belongs_to_attributes(reflection, association_class, table_ids) + # Determine the alias used for remote_table_name, if any. In all cases this will already + # have been assigned an ID in table_ids (either through being involved in a previous join, + # or - if it's the first table in the query - as the default value of table_ids) + remote_table_alias = remote_table_name = association_class.table_name + remote_table_alias += "_#{table_ids[remote_table_name]}" unless table_ids[remote_table_name] == 1 + + # Assign a new alias for the local table. + local_table_alias = local_table_name = reflection.active_record.table_name + if table_ids[local_table_name] + table_id = table_ids[local_table_name] += 1 + local_table_alias += "_#{table_id}" + else + table_ids[local_table_name] = 1 + end + + conditions = '' + # Add type_condition, if applicable + conditions += " AND #{association_class.send(:type_condition).to_sql}" if association_class.finder_needs_type_condition? + # Add custom conditions + conditions += " AND (#{interpolate_sql(association_class.send(:sanitize_sql, reflection.options[:conditions]))})" if reflection.options[:conditions] + + if reflection.macro == :belongs_to + if reflection.options[:polymorphic] + conditions += " AND #{local_table_alias}.#{reflection.options[:foreign_type]} = #{reflection.active_record.quote_value(association_class.base_class.name.to_s)}" + end + { + :joins => reflection.options[:joins], + :remote_key => "#{remote_table_alias}.#{association_class.primary_key}", + :local_key => reflection.primary_key_name, + :conditions => conditions + } + else + # Association is has_many (without :through) + if reflection.options[:as] + conditions += " AND #{remote_table_alias}.#{reflection.options[:as]}_type = #{reflection.active_record.quote_value(reflection.active_record.base_class.name.to_s)}" + end + { + :joins => "#{reflection.options[:joins]}", + :remote_key => "#{remote_table_alias}.#{reflection.primary_key_name}", + :local_key => reflection.klass.primary_key, + :conditions => conditions + } + end + end + + def belongs_to_quoted_key + attribute = @reflection.through_reflection.primary_key_name + column = @owner.column_for_attribute attribute + + @owner.send(:quote_value, @owner.send(attribute), column) + end + + def nested? + through_source_reflection? || through_through_reflection? + end + + def through_source_reflection? + @reflection.source_reflection && @reflection.source_reflection.options[:through] + end + + def through_through_reflection? + @reflection.through_reflection && @reflection.through_reflection.options[:through] + end + end + end +end diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb index db18fb7c0f..ae90d30b42 100644 --- a/activerecord/lib/active_record/reflection.rb +++ b/activerecord/lib/active_record/reflection.rb @@ -378,9 +378,9 @@ module ActiveRecord raise HasManyThroughAssociationPolymorphicError.new(active_record.name, self, source_reflection) end - unless [:belongs_to, :has_many, :has_one].include?(source_reflection.macro) && source_reflection.options[:through].nil? - raise HasManyThroughSourceAssociationMacroError.new(self) - end + # unless [:belongs_to, :has_many, :has_one].include?(source_reflection.macro) && source_reflection.options[:through].nil? + # raise HasManyThroughSourceAssociationMacroError.new(self) + # end check_validity_of_inverse! end diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb index f131dc01f6..0b1a3db1e4 100644 --- a/activerecord/test/cases/associations/join_model_test.rb +++ b/activerecord/test/cases/associations/join_model_test.rb @@ -394,14 +394,6 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase end end - def test_has_many_through_has_many_through - assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).tags } - end - - def test_has_many_through_habtm - assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).post_categories } - end - def test_eager_load_has_many_through_has_many author = Author.find :first, :conditions => ['name = ?', 'David'], :include => :comments, :order => 'comments.id' SpecialComment.new; VerySpecialComment.new diff --git a/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb b/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb new file mode 100644 index 0000000000..36de709ffc --- /dev/null +++ b/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb @@ -0,0 +1,43 @@ +require "cases/helper" +require 'models/author' +require 'models/post' +require 'models/person' +require 'models/reference' +require 'models/job' +require 'models/reader' +require 'models/comment' +require 'models/tag' +require 'models/tagging' +require 'models/owner' +require 'models/pet' +require 'models/toy' +require 'models/contract' +require 'models/company' +require 'models/developer' +require 'models/subscriber' +require 'models/book' +require 'models/subscription' + +class NestedHasManyThroughAssociationsTest < ActiveRecord::TestCase + fixtures :authors, :books, :posts, :subscriptions, :subscribers, :tags, :taggings + + def test_has_many_through_a_has_many_through_association_on_source_reflection + author = authors(:david) + assert_equal [tags(:general), tags(:general)], author.tags + end + + def test_has_many_through_a_has_many_through_association_on_through_reflection + author = authors(:david) + assert_equal [subscribers(:first), subscribers(:second), subscribers(:second)], author.subscribers + end + + def test_distinct_has_many_through_a_has_many_through_association_on_source_reflection + author = authors(:david) + assert_equal [tags(:general)], author.distinct_tags + end + + def test_distinct_has_many_through_a_has_many_through_association_on_through_reflection + author = authors(:david) + assert_equal [subscribers(:first), subscribers(:second)], author.distinct_subscribers + end +end
\ No newline at end of file diff --git a/activerecord/test/fixtures/books.yml b/activerecord/test/fixtures/books.yml index 473663ff5b..fb48645456 100644 --- a/activerecord/test/fixtures/books.yml +++ b/activerecord/test/fixtures/books.yml @@ -1,7 +1,9 @@ awdr: + author_id: 1 id: 1 name: "Agile Web Development with Rails" rfr: + author_id: 1 id: 2 name: "Ruby for Rails" diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb index 34bfd2d881..94810e2f34 100644 --- a/activerecord/test/models/author.rb +++ b/activerecord/test/models/author.rb @@ -83,14 +83,20 @@ class Author < ActiveRecord::Base has_many :author_favorites has_many :favorite_authors, :through => :author_favorites, :order => 'name' - has_many :tagging, :through => :posts # through polymorphic has_one - has_many :taggings, :through => :posts, :source => :taggings # through polymorphic has_many - has_many :tags, :through => :posts # through has_many :through + has_many :tagging, :through => :posts # through polymorphic has_one + has_many :taggings, :through => :posts, :source => :taggings # through polymorphic has_many + has_many :tags, :through => :posts # through has_many :through (on source reflection + polymorphic) + has_many :distinct_tags, :through => :posts, :source => :tags, :select => "DISTINCT tags.*", :order => "tags.name" has_many :post_categories, :through => :posts, :source => :categories + has_many :books + has_many :subscriptions, :through => :books + has_many :subscribers, :through => :subscriptions # through has_many :through (on through reflection) + has_many :distinct_subscribers, :through => :subscriptions, :source => :subscriber, :select => "DISTINCT subscribers.*", :order => "subscribers.nick" + has_one :essay, :primary_key => :name, :as => :writer - belongs_to :author_address, :dependent => :destroy + belongs_to :author_address, :dependent => :destroy belongs_to :author_address_extra, :dependent => :delete, :class_name => "AuthorAddress" scope :relation_include_posts, includes(:posts) diff --git a/activerecord/test/models/book.rb b/activerecord/test/models/book.rb index 1e030b4f59..d27d0af77c 100644 --- a/activerecord/test/models/book.rb +++ b/activerecord/test/models/book.rb @@ -1,4 +1,6 @@ class Book < ActiveRecord::Base + has_many :authors + has_many :citations, :foreign_key => 'book1_id' has_many :references, :through => :citations, :source => :reference_of, :uniq => true diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb index ea62833d81..dbd5da45eb 100644 --- a/activerecord/test/schema/schema.rb +++ b/activerecord/test/schema/schema.rb @@ -71,6 +71,7 @@ ActiveRecord::Schema.define do end create_table :books, :force => true do |t| + t.integer :author_id t.column :name, :string end |