diff options
Diffstat (limited to 'activerecord/lib/active_record/reflection.rb')
| -rw-r--r-- | activerecord/lib/active_record/reflection.rb | 322 |
1 files changed, 206 insertions, 116 deletions
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb index f23ed263fb..dd746a4e10 100644 --- a/activerecord/lib/active_record/reflection.rb +++ b/activerecord/lib/active_record/reflection.rb @@ -1,4 +1,5 @@ require 'thread' +require 'active_support/core_ext/string/filters' module ActiveRecord # = Active Record Reflection @@ -13,14 +14,21 @@ module ActiveRecord 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) @@ -31,9 +39,9 @@ module ActiveRecord 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. # @@ -55,7 +63,7 @@ module ActiveRecord # Returns a Hash of name of the reflection as the key and a AssociationReflection as the value. # - # Account.reflections # => {balance: AggregateReflection} + # Account.reflections # => {"balance" => AggregateReflection} # # @api public def reflections @@ -110,26 +118,67 @@ module ActiveRecord 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(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. # # 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. @@ -142,8 +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 @@ -167,15 +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, @@ -188,23 +232,6 @@ module ActiveRecord active_record == other_aggregation.active_record end - JoinKeys = Struct.new(:key, :foreign_key) # :nodoc: - - def join_keys(assoc_klass) - if source_macro == :belongs_to - if polymorphic? - reflection_key = association_primary_key(assoc_klass) - else - reflection_key = association_primary_key - end - reflection_foreign_key = foreign_key - else - reflection_key = foreign_key - reflection_foreign_key = active_record_primary_key - end - JoinKeys.new(reflection_key, reflection_foreign_key) - end - private def derive_class_name name.to_s.camelize @@ -237,17 +264,20 @@ 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 = macro == :has_many @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 = {} @@ -257,31 +287,17 @@ module ActiveRecord def association_scope_cache(conn, owner) key = conn.prepared_statements if polymorphic? - key = [key, owner.read_attribute(@foreign_type)] + key = [key, owner._read_attribute(@foreign_type)] end @association_scope_cache[key] ||= @scope_lock.synchronize { @association_scope_cache[key] ||= yield } 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 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 @@ -290,10 +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 @@ -331,19 +343,20 @@ module ActiveRecord return unless scope if scope.arity > 0 - ActiveSupport::Deprecation.warn <<-WARNING -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. - WARNING + 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: - key = (source_macro == :belongs_to) ? foreign_key : active_record_primary_key - owner[key] + def join_id_for(owner) # :nodoc: + owner[active_record_primary_key] end def through_reflection @@ -370,8 +383,6 @@ Joining, Preloading and eager loading of these associations is deprecated and wi scope ? [[scope]] : [[]] end - alias :source_macro :macro - def has_inverse? inverse_name end @@ -392,11 +403,16 @@ Joining, Preloading and eager loading of these associations is deprecated and wi 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 @@ -413,14 +429,10 @@ Joining, Preloading and eager loading of these associations is deprecated and wi 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? - macro == :has_one - end + def has_one?; false; end def association_class case macro @@ -552,7 +564,7 @@ Joining, Preloading and eager loading of these associations is deprecated and wi 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) @@ -560,22 +572,72 @@ Joining, Preloading and eager loading of these associations is deprecated and wi end end - class HasAndBelongsToManyReflection < AssociationReflection #:nodoc: - def initialize(macro, name, scope, options, active_record) + 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 - @collection = true + 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 @@ -593,7 +655,7 @@ Joining, Preloading and eager loading of these associations is deprecated and wi # # 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) @@ -609,7 +671,7 @@ Joining, Preloading and eager loading of these associations is deprecated and wi # # 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]) @@ -629,8 +691,8 @@ Joining, Preloading and eager loading of these associations is deprecated and wi # # 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 @@ -671,8 +733,11 @@ Joining, Preloading and eager loading of these associations is deprecated and wi 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 @@ -680,8 +745,17 @@ Joining, Preloading and eager loading of these associations is deprecated and wi 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 @@ -717,7 +791,7 @@ Joining, Preloading and eager loading of these associations is deprecated and wi 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) } @@ -725,15 +799,13 @@ Joining, Preloading and eager loading of these associations is deprecated and wi 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 @@ -747,13 +819,21 @@ 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.polymorphic? - raise HasManyThroughAssociationPolymorphicThroughError.new(active_record.name, self) + if has_one? + raise HasOneAssociationPolymorphicThroughError.new(active_record.name, self) + else + raise HasManyThroughAssociationPolymorphicThroughError.new(active_record.name, self) + end end if source_reflection.nil? @@ -777,15 +857,25 @@ directive on your declaration like: 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 end end |