diff options
Diffstat (limited to 'activerecord/lib/active_record/reflection.rb')
| -rw-r--r-- | activerecord/lib/active_record/reflection.rb | 476 |
1 files changed, 367 insertions, 109 deletions
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb index bce7766501..dab5a502a5 100644 --- a/activerecord/lib/active_record/reflection.rb +++ b/activerecord/lib/active_record/reflection.rb @@ -1,37 +1,47 @@ +require 'thread' +require 'active_support/core_ext/string/filters' + module ActiveRecord # = Active Record Reflection module Reflection # :nodoc: extend ActiveSupport::Concern included do - class_attribute :reflections + class_attribute :_reflections class_attribute :aggregate_reflections - self.reflections = {} + self._reflections = {} self.aggregate_reflections = {} end def self.create(macro, name, scope, options, ar) - case macro - when :has_many, :belongs_to, :has_one - klass = options[:through] ? ThroughReflection : AssociationReflection - when :composed_of - klass = AggregateReflection - end - - klass.new(macro, name, scope, options, ar) + klass = case macro + when :composed_of + AggregateReflection + when :has_many + HasManyReflection + when :has_one + HasOneReflection + when :belongs_to + BelongsToReflection + else + raise "Unsupported Macro: #{macro}" + end + + reflection = klass.new(name, scope, options, ar) + options[:through] ? ThroughReflection.new(reflection) : reflection end def self.add_reflection(ar, name, reflection) - ar.reflections = ar.reflections.merge(name => reflection) + ar._reflections = ar._reflections.merge(name.to_s => reflection) end def self.add_aggregate_reflection(ar, name, reflection) - ar.aggregate_reflections = ar.aggregate_reflections.merge(name => reflection) + ar.aggregate_reflections = ar.aggregate_reflections.merge(name.to_s => reflection) end - # \Reflection enables to interrogate Active Record classes and objects - # about their associations and aggregations. This information can, - # for example, be used in a form builder that takes an Active Record object + # \Reflection enables the ability to examine the associations and aggregations of + # Active Record classes and objects. This information, for example, + # can be used in a form builder that takes an Active Record object # and creates input fields for all of the attributes depending on their type # and displays the associations to other objects. # @@ -48,7 +58,25 @@ module ActiveRecord # Account.reflect_on_aggregation(:balance) # => the balance AggregateReflection # def reflect_on_aggregation(aggregation) - aggregate_reflections[aggregation] + aggregate_reflections[aggregation.to_s] + end + + # Returns a Hash of name of the reflection as the key and a AssociationReflection as the value. + # + # Account.reflections # => {"balance" => AggregateReflection} + # + # @api public + def reflections + ref = {} + _reflections.each do |name, reflection| + parent_name, parent_reflection = reflection.parent_reflection + if parent_name + ref[parent_name] = parent_reflection + else + ref[name] = reflection + end + end + ref end # Returns an array of AssociationReflection objects for all the @@ -61,6 +89,7 @@ module ActiveRecord # Account.reflect_on_all_associations # returns an array of all associations # Account.reflect_on_all_associations(:has_many) # returns an array of all has_many associations # + # @api public def reflect_on_all_associations(macro = nil) association_reflections = reflections.values macro ? association_reflections.select { |reflection| reflection.macro == macro } : association_reflections @@ -71,36 +100,85 @@ module ActiveRecord # Account.reflect_on_association(:owner) # returns the owner AssociationReflection # Invoice.reflect_on_association(:line_items).macro # returns :has_many # + # @api public def reflect_on_association(association) - reflections[association] + reflections[association.to_s] + end + + # @api private + def _reflect_on_association(association) #:nodoc: + _reflections[association.to_s] end # Returns an array of AssociationReflection objects for all associations which have <tt>:autosave</tt> enabled. + # + # @api public def reflect_on_all_autosave_associations reflections.values.select { |reflection| reflection.options[:autosave] } end end + # Holds all the methods that are shared between MacroReflection, AssociationReflection + # and ThroughReflection + class AbstractReflection # :nodoc: + def table_name + klass.table_name + end + + # Returns a new, unsaved instance of the associated class. +attributes+ will + # be passed to the class's constructor. + def build_association(attributes, &block) + klass.new(attributes, &block) + end + + def quoted_table_name + klass.quoted_table_name + end + + def primary_key_type + klass.type_for_attribute(klass.primary_key) + end + + # Returns the class name for the macro. + # + # <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>'Money'</tt> + # <tt>has_many :clients</tt> returns <tt>'Client'</tt> + def class_name + @class_name ||= (options[:class_name] || derive_class_name).to_s + end + + JoinKeys = Struct.new(:key, :foreign_key) # :nodoc: + + def join_keys(association_klass) + JoinKeys.new(foreign_key, active_record_primary_key) + end + + def constraints + scope_chain.flatten + end + + def alias_candidate(name) + "#{plural_name}_#{name}" + end + end + # Base class for AggregateReflection and AssociationReflection. Objects of # AggregateReflection and AssociationReflection are returned by the Reflection::ClassMethods. # # MacroReflection - # AggregateReflection # AssociationReflection - # ThroughReflection - class MacroReflection + # AggregateReflection + # HasManyReflection + # HasOneReflection + # BelongsToReflection + # ThroughReflection + class MacroReflection < AbstractReflection # Returns the name of the macro. # # <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>:balance</tt> # <tt>has_many :clients</tt> returns <tt>:clients</tt> attr_reader :name - # Returns the macro type. - # - # <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>:composed_of</tt> - # <tt>has_many :clients</tt> returns <tt>:has_many</tt> - attr_reader :macro - attr_reader :scope # Returns the hash of options used for the macro. @@ -113,8 +191,7 @@ module ActiveRecord attr_reader :plural_name # :nodoc: - def initialize(macro, name, scope, options, active_record) - @macro = macro + def initialize(name, scope, options, active_record) @name = name @scope = scope @options = options @@ -127,6 +204,10 @@ module ActiveRecord def autosave=(autosave) @automatic_inverse_of = false @options[:autosave] = autosave + _, parent_reflection = self.parent_reflection + if parent_reflection + parent_reflection.autosave = autosave + end end # Returns the class for the macro. @@ -134,15 +215,11 @@ module ActiveRecord # <tt>composed_of :balance, class_name: 'Money'</tt> returns the Money class # <tt>has_many :clients</tt> returns the Client class def klass - @klass ||= class_name.constantize + @klass ||= compute_class(class_name) end - # Returns the class name for the macro. - # - # <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>'Money'</tt> - # <tt>has_many :clients</tt> returns <tt>'Client'</tt> - def class_name - @class_name ||= (options[:class_name] || derive_class_name).to_s + def compute_class(name) + name.constantize end # Returns +true+ if +self+ and +other_aggregation+ have the same +name+ attribute, +active_record+ attribute, @@ -151,7 +228,7 @@ module ActiveRecord super || other_aggregation.kind_of?(self.class) && name == other_aggregation.name && - other_aggregation.options && + !other_aggregation.options.nil? && active_record == other_aggregation.active_record end @@ -187,38 +264,40 @@ module ActiveRecord # a new association object. Use +build_association+ or +create_association+ # instead. This allows plugins to hook into association object creation. def klass - @klass ||= active_record.send(:compute_type, class_name) + @klass ||= compute_class(class_name) + end + + def compute_class(name) + active_record.send(:compute_type, name) end attr_reader :type, :foreign_type + attr_accessor :parent_reflection # [:name, Reflection] - def initialize(macro, name, scope, options, active_record) + def initialize(name, scope, options, active_record) super - @collection = :has_many == macro @automatic_inverse_of = nil - @type = options[:as] && "#{options[:as]}_type" + @type = options[:as] && (options[:foreign_type] || "#{options[:as]}_type") @foreign_type = options[:foreign_type] || "#{name}_type" @constructable = calculate_constructable(macro, options) + @association_scope_cache = {} + @scope_lock = Mutex.new end - # Returns a new, unsaved instance of the associated class. +attributes+ will - # be passed to the class's constructor. - def build_association(attributes, &block) - klass.new(attributes, &block) + def association_scope_cache(conn, owner) + key = conn.prepared_statements + if polymorphic? + key = [key, owner._read_attribute(@foreign_type)] + end + @association_scope_cache[key] ||= @scope_lock.synchronize { + @association_scope_cache[key] ||= yield + } end def constructable? # :nodoc: @constructable end - def table_name - klass.table_name - end - - def quoted_table_name - klass.quoted_table_name - end - def join_table @join_table ||= options[:join_table] || derive_join_table end @@ -227,10 +306,6 @@ module ActiveRecord @foreign_key ||= options[:foreign_key] || derive_foreign_key end - def primary_key_column - klass.columns_hash[klass.primary_key] - end - def association_foreign_key @association_foreign_key ||= options[:association_foreign_key] || class_name.foreign_key end @@ -257,13 +332,30 @@ module ActiveRecord end def check_validity_of_inverse! - unless options[:polymorphic] + unless polymorphic? if has_inverse? && inverse_of.nil? raise InverseOfAssociationNotFoundError.new(self) end end end + def check_preloadable! + return unless scope + + if scope.arity > 0 + raise ArgumentError, <<-MSG.squish + The association scope '#{name}' is instance dependent (the scope + block takes an argument). Preloading instance dependent scopes is + not supported. + MSG + end + end + alias :check_eager_loadable! :check_preloadable! + + def join_id_for(owner) # :nodoc: + owner[active_record_primary_key] + end + def through_reflection nil end @@ -288,8 +380,6 @@ module ActiveRecord scope ? [[scope]] : [[]] end - alias :source_macro :macro - def has_inverse? inverse_name end @@ -297,12 +387,12 @@ module ActiveRecord def inverse_of return unless inverse_name - @inverse_of ||= klass.reflect_on_association inverse_name + @inverse_of ||= klass._reflect_on_association inverse_name end def polymorphic_inverse_of(associated_class) if has_inverse? - if inverse_relationship = associated_class.reflect_on_association(options[:inverse_of]) + if inverse_relationship = associated_class._reflect_on_association(options[:inverse_of]) inverse_relationship else raise InverseOfAssociationNotFoundError.new(self, associated_class) @@ -310,11 +400,16 @@ module ActiveRecord end end + # Returns the macro type. + # + # <tt>has_many :clients</tt> returns <tt>:has_many</tt> + def macro; raise NotImplementedError; end + # Returns whether or not this association reflection is for a collection # association. Returns +true+ if the +macro+ is either +has_many+ or # +has_and_belongs_to_many+, +false+ otherwise. def collection? - @collection + false end # Returns whether or not the association should be validated as part of @@ -327,18 +422,19 @@ module ActiveRecord # * you use autosave; <tt>autosave: true</tt> # * the association is a +has_many+ association def validate? - !options[:validate].nil? ? options[:validate] : (options[:autosave] == true || macro == :has_many) + !options[:validate].nil? ? options[:validate] : (options[:autosave] == true || collection?) end # Returns +true+ if +self+ is a +belongs_to+ reflection. - def belongs_to? - macro == :belongs_to - end + def belongs_to?; false; end + + # Returns +true+ if +self+ is a +has_one+ reflection. + def has_one?; false; end def association_class case macro when :belongs_to - if options[:polymorphic] + if polymorphic? Associations::BelongsToPolymorphicAssociation else Associations::BelongsToAssociation @@ -359,7 +455,7 @@ module ActiveRecord end def polymorphic? - options.key? :polymorphic + options[:polymorphic] end VALID_AUTOMATIC_INVERSE_MACROS = [:has_many, :has_one, :belongs_to] @@ -376,7 +472,7 @@ module ActiveRecord def calculate_constructable(macro, options) case macro when :belongs_to - !options[:polymorphic] + !polymorphic? when :has_one !options[:through] else @@ -400,10 +496,10 @@ module ActiveRecord # returns either nil or the inverse association name that it finds. def automatic_inverse_of if can_find_inverse_of_automatically?(self) - inverse_name = ActiveSupport::Inflector.underscore(active_record.name).to_sym + inverse_name = ActiveSupport::Inflector.underscore(options[:as] || active_record.name.demodulize).to_sym begin - reflection = klass.reflect_on_association(inverse_name) + reflection = klass._reflect_on_association(inverse_name) rescue NameError # Give up: we couldn't compute the klass type so we won't be able # to find any associations either. @@ -449,9 +545,9 @@ module ActiveRecord end def derive_class_name - class_name = name.to_s.camelize + class_name = name.to_s class_name = class_name.singularize if collection? - class_name + class_name.camelize end def derive_foreign_key @@ -465,7 +561,7 @@ module ActiveRecord end def derive_join_table - [active_record.table_name, klass.table_name].sort.join("\0").gsub(/^(.*_)(.+)\0\1(.+)/, '\1\2_\3').gsub("\0", "_") + ModelSchema.derive_join_table_name active_record.table_name, klass.table_name end def primary_key(klass) @@ -473,15 +569,72 @@ module ActiveRecord end end + class HasManyReflection < AssociationReflection # :nodoc: + def initialize(name, scope, options, active_record) + super(name, scope, options, active_record) + end + + def macro; :has_many; end + + def collection?; true; end + end + + class HasOneReflection < AssociationReflection # :nodoc: + def initialize(name, scope, options, active_record) + super(name, scope, options, active_record) + end + + def macro; :has_one; end + + def has_one?; true; end + end + + class BelongsToReflection < AssociationReflection # :nodoc: + def initialize(name, scope, options, active_record) + super(name, scope, options, active_record) + end + + def macro; :belongs_to; end + + def belongs_to?; true; end + + def join_keys(association_klass) + key = polymorphic? ? association_primary_key(association_klass) : association_primary_key + JoinKeys.new(key, foreign_key) + end + + def join_id_for(owner) # :nodoc: + owner[foreign_key] + end + end + + class HasAndBelongsToManyReflection < AssociationReflection # :nodoc: + def initialize(name, scope, options, active_record) + super + end + + def macro; :has_and_belongs_to_many; end + + def collection? + true + end + end + # Holds all the meta-data about a :through association as it was specified # in the Active Record class. - class ThroughReflection < AssociationReflection #:nodoc: + class ThroughReflection < AbstractReflection #:nodoc: + attr_reader :delegate_reflection delegate :foreign_key, :foreign_type, :association_foreign_key, :active_record_primary_key, :type, :to => :source_reflection - def initialize(macro, name, scope, options, active_record) - super - @source_reflection_name = options[:source] + def initialize(delegate_reflection) + @delegate_reflection = delegate_reflection + @klass = delegate_reflection.options[:class] + @source_reflection_name = delegate_reflection.options[:source] + end + + def klass + @klass ||= delegate_reflection.compute_class(class_name) end # Returns the source of the through reflection. It checks both a singularized @@ -499,10 +652,10 @@ module ActiveRecord # # tags_reflection = Post.reflect_on_association(:tags) # tags_reflection.source_reflection - # # => <ActiveRecord::Reflection::AssociationReflection: @macro=:belongs_to, @name=:tag, @active_record=Tagging, @plural_name="tags"> + # # => <ActiveRecord::Reflection::BelongsToReflection: @name=:tag, @active_record=Tagging, @plural_name="tags"> # def source_reflection - through_reflection.klass.reflect_on_association(source_reflection_name) + through_reflection.klass._reflect_on_association(source_reflection_name) end # Returns the AssociationReflection object specified in the <tt>:through</tt> option @@ -515,10 +668,10 @@ module ActiveRecord # # tags_reflection = Post.reflect_on_association(:tags) # tags_reflection.through_reflection - # # => <ActiveRecord::Reflection::AssociationReflection: @macro=:has_many, @name=:taggings, @active_record=Post, @plural_name="taggings"> + # # => <ActiveRecord::Reflection::HasManyReflection: @name=:taggings, @active_record=Post, @plural_name="taggings"> # def through_reflection - active_record.reflect_on_association(options[:through]) + active_record._reflect_on_association(options[:through]) end # Returns an array of reflections which are involved in this association. Each item in the @@ -535,13 +688,18 @@ module ActiveRecord # # tags_reflection = Post.reflect_on_association(:tags) # tags_reflection.chain - # # => [<ActiveRecord::Reflection::ThroughReflection: @macro=:has_many, @name=:tags, @options={:through=>:taggings}, @active_record=Post>, - # <ActiveRecord::Reflection::AssociationReflection: @macro=:has_many, @name=:taggings, @options={}, @active_record=Post>] + # # => [<ActiveRecord::Reflection::ThroughReflection: @delegate_reflection=#<ActiveRecord::Reflection::HasManyReflection: @name=:tags...>, + # <ActiveRecord::Reflection::HasManyReflection: @name=:taggings, @options={}, @active_record=Post>] # def chain @chain ||= begin a = source_reflection.chain b = through_reflection.chain + + if options[:source_type] + b[0] = PolymorphicReflection.new(b[0], self) + end + chain = a + b chain[0] = self # Use self so we don't lose the information from :source_type chain @@ -577,8 +735,11 @@ module ActiveRecord through_scope_chain = through_reflection.scope_chain.map(&:dup) if options[:source_type] - through_scope_chain.first << - through_reflection.klass.where(foreign_type => options[:source_type]) + type = foreign_type + source_type = options[:source_type] + through_scope_chain.first << lambda { |object| + where(type => source_type) + } end # Recursively fill out the rest of the array from the through reflection @@ -586,9 +747,8 @@ module ActiveRecord end end - # The macro used by the source association - def source_macro - source_reflection.source_macro + def join_keys(association_klass) + source_reflection.join_keys(association_klass) end # A through association is nested if there would be more than one join table @@ -617,29 +777,27 @@ module ActiveRecord # # => [:tag, :tags] # def source_reflection_names - (options[:source] ? [options[:source]] : [name.to_s.singularize, name]).collect { |n| n.to_sym }.uniq + options[:source] ? [options[:source]] : [name.to_s.singularize, name].uniq end def source_reflection_name # :nodoc: return @source_reflection_name if @source_reflection_name - names = [name.to_s.singularize, name].collect { |n| n.to_sym }.uniq + names = [name.to_s.singularize, name].collect(&:to_sym).uniq names = names.find_all { |n| - through_reflection.klass.reflect_on_association(n) + through_reflection.klass._reflect_on_association(n) } if names.length > 1 example_options = options.dup example_options[:source] = source_reflection_names.first - ActiveSupport::Deprecation.warn <<-eowarn -Ambiguous source reflection for through association. Please specify a :source -directive on your declaration like: - - class #{active_record.name} < ActiveRecord::Base - #{macro} :#{name}, #{example_options} - end - - eowarn + ActiveSupport::Deprecation.warn \ + "Ambiguous source reflection for through association. Please " \ + "specify a :source directive on your declaration like:\n" \ + "\n" \ + " class #{active_record.name} < ActiveRecord::Base\n" \ + " #{macro} :#{name}, #{example_options}\n" \ + " end" end @source_reflection_name = names.first @@ -653,45 +811,145 @@ directive on your declaration like: through_reflection.options end + def join_id_for(owner) # :nodoc: + source_reflection.join_id_for(owner) + end + def check_validity! if through_reflection.nil? raise HasManyThroughAssociationNotFoundError.new(active_record.name, self) end - if through_reflection.options[:polymorphic] - raise HasManyThroughAssociationPolymorphicThroughError.new(active_record.name, self) + if through_reflection.polymorphic? + if has_one? + raise HasOneAssociationPolymorphicThroughError.new(active_record.name, self) + else + raise HasManyThroughAssociationPolymorphicThroughError.new(active_record.name, self) + end end if source_reflection.nil? raise HasManyThroughSourceAssociationNotFoundError.new(self) end - if options[:source_type] && source_reflection.options[:polymorphic].nil? + if options[:source_type] && !source_reflection.polymorphic? raise HasManyThroughAssociationPointlessSourceTypeError.new(active_record.name, self, source_reflection) end - if source_reflection.options[:polymorphic] && options[:source_type].nil? + if source_reflection.polymorphic? && options[:source_type].nil? raise HasManyThroughAssociationPolymorphicSourceError.new(active_record.name, self, source_reflection) end - if macro == :has_one && through_reflection.collection? + if has_one? && through_reflection.collection? raise HasOneThroughCantAssociateThroughCollection.new(active_record.name, self, through_reflection) end check_validity_of_inverse! end + def constraints + scope_chain = source_reflection.constraints + scope_chain << scope if scope + scope_chain + end + protected - def actual_source_reflection # FIXME: this is a horrible name - source_reflection.actual_source_reflection - end + def actual_source_reflection # FIXME: this is a horrible name + source_reflection.send(:actual_source_reflection) + end + + def primary_key(klass) + klass.primary_key || raise(UnknownPrimaryKey.new(klass)) + end private def derive_class_name # get the class_name of the belongs_to association of the through reflection options[:source_type] || source_reflection.class_name end + + delegate_methods = AssociationReflection.public_instance_methods - + public_instance_methods + + delegate(*delegate_methods, to: :delegate_reflection) + + end + + class PolymorphicReflection < ThroughReflection # :nodoc: + def initialize(reflection, previous_reflection) + @reflection = reflection + @previous_reflection = previous_reflection + end + + def klass + @reflection.klass + end + + def scope + @reflection.scope + end + + def table_name + @reflection.table_name + end + + def plural_name + @reflection.plural_name + end + + def join_keys(association_klass) + @reflection.join_keys(association_klass) + end + + def type + @reflection.type + end + + def constraints + [source_type_info] + end + + def source_type_info + type = @previous_reflection.foreign_type + source_type = @previous_reflection.options[:source_type] + lambda { |object| where(type => source_type) } + end + end + + class RuntimeReflection < PolymorphicReflection # :nodoc: + attr_accessor :next + + def initialize(reflection, association) + @reflection = reflection + @association = association + end + + def klass + @association.klass + end + + def table_name + klass.table_name + end + + def constraints + @reflection.constraints + end + + def source_type_info + @reflection.source_type_info + end + + def alias_candidate(name) + "#{plural_name}_#{name}_join" + end + + def alias_name + Arel::Table.new(table_name) + end + + def all_includes; yield; end end end end |