diff options
Diffstat (limited to 'activerecord/lib/active_record/reflection.rb')
| -rw-r--r-- | activerecord/lib/active_record/reflection.rb | 586 |
1 files changed, 458 insertions, 128 deletions
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb index bcfcb061f2..dd746a4e10 100644 --- a/activerecord/lib/active_record/reflection.rb +++ b/activerecord/lib/active_record/reflection.rb @@ -1,3 +1,5 @@ +require 'thread' +require 'active_support/core_ext/string/filters' module ActiveRecord # = Active Record Reflection @@ -5,35 +7,50 @@ module ActiveRecord extend ActiveSupport::Concern included do - class_attribute :reflections - self.reflections = {} + class_attribute :_reflections + class_attribute :aggregate_reflections + self._reflections = {} + self.aggregate_reflections = {} 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 + def self.create(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.to_s => reflection) + end + + def self.add_aggregate_reflection(ar, name, reflection) + ar.aggregate_reflections = ar.aggregate_reflections.merge(name.to_s => reflection) + end + + # \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. # # MacroReflection class has info for AggregateReflection and AssociationReflection # classes. module ClassMethods - def create_reflection(macro, name, scope, options, active_record) - case macro - when :has_many, :belongs_to, :has_one, :has_and_belongs_to_many - klass = options[:through] ? ThroughReflection : AssociationReflection - reflection = klass.new(macro, name, scope, options, active_record) - when :composed_of - reflection = AggregateReflection.new(macro, name, scope, options, active_record) - end - - self.reflections = self.reflections.merge(name => reflection) - reflection - end - # Returns an array of AggregateReflection objects for all the aggregations in the class. def reflect_on_all_aggregations - reflections.values.grep(AggregateReflection) + aggregate_reflections.values end # Returns the AggregateReflection object for the named +aggregation+ (use the symbol). @@ -41,8 +58,25 @@ module ActiveRecord # Account.reflect_on_aggregation(:balance) # => the balance AggregateReflection # def reflect_on_aggregation(aggregation) - reflection = reflections[aggregation] - reflection if reflection.is_a?(AggregateReflection) + 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 @@ -55,8 +89,9 @@ 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.grep(AssociationReflection) + association_reflections = reflections.values macro ? association_reflections.select { |reflection| reflection.macro == macro } : association_reflections end @@ -65,68 +100,126 @@ 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) - reflection = reflections[association] - reflection if reflection.is_a?(AssociationReflection) + 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 - # Abstract base class for AggregateReflection and AssociationReflection. Objects of + # 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(assoc_klass) + JoinKeys.new(foreign_key, active_record_primary_key) + end + + def source_macro + ActiveSupport::Deprecation.warn(<<-MSG.squish) + ActiveRecord::Base.source_macro is deprecated and will be removed + without replacement. + MSG + + macro + end + end + # Base class for AggregateReflection and AssociationReflection. Objects of # AggregateReflection and AssociationReflection are returned by the Reflection::ClassMethods. - class MacroReflection + # + # MacroReflection + # AssociationReflection + # 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. # # <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>{ class_name: "Money" }</tt> - # <tt>has_many :clients</tt> returns +{}+ + # <tt>has_many :clients</tt> returns <tt>{}</tt> attr_reader :options attr_reader :active_record 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 @active_record = active_record + @klass = options[:class] @plural_name = active_record.pluralize_table_names ? name.to_s.pluralize : name.to_s end + 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. # # <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, @@ -135,7 +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 @@ -171,26 +264,38 @@ 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 initialize(*args) - super - @collection = [:has_many, :has_and_belongs_to_many].include?(macro) + def compute_class(name) + active_record.send(:compute_type, 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 + attr_reader :type, :foreign_type + attr_accessor :parent_reflection # [:name, Reflection] - def table_name - @table_name ||= klass.table_name + def initialize(name, scope, options, active_record) + super + @automatic_inverse_of = nil + @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 + + 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 quoted_table_name - @quoted_table_name ||= klass.quoted_table_name + def constructable? # :nodoc: + @constructable end def join_table @@ -201,18 +306,6 @@ module ActiveRecord @foreign_key ||= options[:foreign_key] || derive_foreign_key end - def foreign_type - @foreign_type ||= options[:foreign_type] || "#{name}_type" - end - - def type - @type ||= options[:as] && "#{options[:as]}_type" - end - - def primary_key_column - @primary_key_column ||= klass.columns.find { |c| c.name == klass.primary_key } - end - def association_foreign_key @association_foreign_key ||= options[:association_foreign_key] || class_name.foreign_key end @@ -234,36 +327,44 @@ module ActiveRecord end end - def columns(tbl_name) - @columns ||= klass.connection.columns(tbl_name) - end - - def reset_column_information - @columns = nil - end - def check_validity! check_validity_of_inverse! - - if has_and_belongs_to_many? && association_foreign_key == foreign_key - raise HasAndBelongsToManyAssociationForeignKeyNeeded.new(self) - end 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 + ActiveSupport::Deprecation.warn(<<-MSG.squish) + The association scope '#{name}' is instance dependent (the scope + block takes an argument). Preloading happens before the individual + instances are created. This means that there is no instance being + passed to the association scope. This will most likely result in + broken or incorrect behavior. Joining, Preloading and eager loading + of these associations is deprecated and will be removed in the future. + 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 def source_reflection - nil + self end # A chain of reflections from this one back to the owner. For more see the explanation in @@ -282,21 +383,19 @@ module ActiveRecord scope ? [[scope]] : [[]] end - alias :source_macro :macro - def has_inverse? - @options[:inverse_of] + inverse_name end def inverse_of - if has_inverse? - @inverse_of ||= klass.reflect_on_association(options[:inverse_of]) - end + return unless 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) @@ -304,11 +403,16 @@ 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 @@ -321,28 +425,23 @@ 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 - def has_and_belongs_to_many? - macro == :has_and_belongs_to_many - 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 end - when :has_and_belongs_to_many - Associations::HasAndBelongsToManyAssociation when :has_many if options[:through] Associations::HasManyThroughAssociation @@ -359,14 +458,99 @@ module ActiveRecord end def polymorphic? - options.key? :polymorphic + options[:polymorphic] end + VALID_AUTOMATIC_INVERSE_MACROS = [:has_many, :has_one, :belongs_to] + INVALID_AUTOMATIC_INVERSE_OPTIONS = [:conditions, :through, :polymorphic, :foreign_key] + + protected + + def actual_source_reflection # FIXME: this is a horrible name + self + end + private + + def calculate_constructable(macro, options) + case macro + when :belongs_to + !polymorphic? + when :has_one + !options[:through] + else + true + end + end + + # Attempts to find the inverse association name automatically. + # If it cannot find a suitable inverse association name, it returns + # nil. + def inverse_name + options.fetch(:inverse_of) do + if @automatic_inverse_of == false + nil + else + @automatic_inverse_of ||= automatic_inverse_of + end + end + end + + # 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(options[:as] || active_record.name.demodulize).to_sym + + begin + 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. + reflection = false + end + + if valid_inverse_reflection?(reflection) + return inverse_name + end + end + + false + end + + # Checks if the inverse reflection that is returned from the + # +automatic_inverse_of+ method is a valid reflection. We must + # make sure that the reflection's active_record name matches up + # with the current reflection's klass name. + # + # Note: klass will always be valid because when there's a NameError + # from calling +klass+, +reflection+ will already be set to false. + def valid_inverse_reflection?(reflection) + reflection && + klass.name == reflection.active_record.name && + can_find_inverse_of_automatically?(reflection) + end + + # Checks to see if the reflection doesn't have any options that prevent + # us from being able to guess the inverse automatically. First, the + # <tt>inverse_of</tt> option cannot be set to false. Second, we must + # have <tt>has_many</tt>, <tt>has_one</tt>, <tt>belongs_to</tt> associations. + # Third, we must not have options such as <tt>:polymorphic</tt> or + # <tt>:foreign_key</tt> which prevent us from correctly guessing the + # inverse association. + # + # Anything with a scope can additionally ruin our attempt at finding an + # inverse, so we exclude reflections with scopes. + def can_find_inverse_of_automatically?(reflection) + reflection.options[:inverse_of] != false && + VALID_AUTOMATIC_INVERSE_MACROS.include?(reflection.macro) && + !INVALID_AUTOMATIC_INVERSE_OPTIONS.any? { |opt| reflection.options[opt] } && + !reflection.scope + 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 @@ -380,7 +564,7 @@ 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) @@ -388,13 +572,75 @@ 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(assoc_klass) + key = polymorphic? ? association_primary_key(assoc_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 - # Gets the source of the through reflection. It checks both a singularized + 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 # and pluralized form for <tt>:belongs_to</tt> or <tt>:has_many</tt>. # # class Post < ActiveRecord::Base @@ -402,8 +648,17 @@ module ActiveRecord # has_many :tags, through: :taggings # end # + # class Tagging < ActiveRecord::Base + # belongs_to :post + # belongs_to :tag + # end + # + # tags_reflection = Post.reflect_on_association(:tags) + # tags_reflection.source_reflection + # # => <ActiveRecord::Reflection::BelongsToReflection: @name=:tag, @active_record=Tagging, @plural_name="tags"> + # def source_reflection - @source_reflection ||= source_reflection_names.collect { |name| through_reflection.klass.reflect_on_association(name) }.compact.first + through_reflection.klass._reflect_on_association(source_reflection_name) end # Returns the AssociationReflection object specified in the <tt>:through</tt> option @@ -415,10 +670,11 @@ module ActiveRecord # end # # tags_reflection = Post.reflect_on_association(:tags) - # taggings_reflection = tags_reflection.through_reflection + # tags_reflection.through_reflection + # # => <ActiveRecord::Reflection::HasManyReflection: @name=:taggings, @active_record=Post, @plural_name="taggings"> # def through_reflection - @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 @@ -427,9 +683,22 @@ module ActiveRecord # The chain is built by recursively calling #chain on the source reflection and the through # reflection. The base case for the recursion is a normal association, which just returns # [self] as its #chain. + # + # class Post < ActiveRecord::Base + # has_many :taggings + # has_many :tags, through: :taggings + # end + # + # tags_reflection = Post.reflect_on_association(:tags) + # tags_reflection.chain + # # => [<ActiveRecord::Reflection::ThroughReflection: @delegate_reflection=#<ActiveRecord::Reflection::HasManyReflection: @name=:tags...>, + # <ActiveRecord::Reflection::HasManyReflection: @name=:taggings, @options={}, @active_record=Post>] + # def chain @chain ||= begin - chain = source_reflection.chain + through_reflection.chain + a = source_reflection.chain + b = through_reflection.chain + chain = a + b chain[0] = self # Use self so we don't lose the information from :source_type chain end @@ -461,11 +730,14 @@ module ActiveRecord # Add to it the scope from this reflection (if any) scope_chain.first << scope if scope - through_scope_chain = through_reflection.scope_chain + 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 @@ -473,14 +745,23 @@ module ActiveRecord end end + def join_keys(assoc_klass) + source_reflection.join_keys(assoc_klass) + end + # The macro used by the source association def source_macro + ActiveSupport::Deprecation.warn(<<-MSG.squish) + ActiveRecord::Base.source_macro is deprecated and will be removed + without replacement. + MSG + source_reflection.source_macro end # A through association is nested if there would be more than one join table def nested? - chain.length > 2 || through_reflection.macro == :has_and_belongs_to_many + chain.length > 2 end # We want to use the klass from this reflection, rather than just delegate straight to @@ -489,20 +770,45 @@ module ActiveRecord def association_primary_key(klass = nil) # Get the "actual" source reflection if the immediate source reflection has a # source reflection itself - source_reflection = self.source_reflection - while source_reflection.source_reflection - source_reflection = source_reflection.source_reflection - end - - source_reflection.options[:primary_key] || primary_key(klass || self.klass) + actual_source_reflection.options[:primary_key] || primary_key(klass || self.klass) end - # Gets an array of possible <tt>:through</tt> source reflection names: + # Gets an array of possible <tt>:through</tt> source reflection names in both singular and plural form. + # + # class Post < ActiveRecord::Base + # has_many :taggings + # has_many :tags, through: :taggings + # end # - # [:singularized, :pluralized] + # tags_reflection = Post.reflect_on_association(:tags) + # tags_reflection.source_reflection_names + # # => [:tag, :tags] # def source_reflection_names - @source_reflection_names ||= (options[:source] ? [options[:source]] : [name.to_s.singularize, name]).collect { |n| n.to_sym } + 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(&:to_sym).uniq + names = names.find_all { |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 \ + "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 end def source_options @@ -513,39 +819,63 @@ module ActiveRecord 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 + protected + + 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 end end |