diff options
Diffstat (limited to 'activerecord/lib/active_record/associations.rb')
| -rw-r--r-- | activerecord/lib/active_record/associations.rb | 120 |
1 files changed, 87 insertions, 33 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb index 3c92e379f1..74e2774626 100644 --- a/activerecord/lib/active_record/associations.rb +++ b/activerecord/lib/active_record/associations.rb @@ -73,12 +73,6 @@ module ActiveRecord end end - class HasAndBelongsToManyAssociationForeignKeyNeeded < ActiveRecordError #:nodoc: - def initialize(reflection) - super("Cannot create self referential has_and_belongs_to_many association on '#{reflection.class_name rescue nil}##{reflection.name rescue nil}'. :association_foreign_key cannot be the same as the :foreign_key.") - end - end - class EagerLoadPolymorphicError < ActiveRecordError #:nodoc: def initialize(reflection) super("Can not eagerly load the polymorphic association #{reflection.name.inspect}") @@ -114,7 +108,6 @@ module ActiveRecord autoload :BelongsToAssociation, 'active_record/associations/belongs_to_association' autoload :BelongsToPolymorphicAssociation, 'active_record/associations/belongs_to_polymorphic_association' - 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 :HasOneAssociation, 'active_record/associations/has_one_association' @@ -164,7 +157,7 @@ module ActiveRecord private # Returns the specified association instance if it responds to :loaded?, nil otherwise. def association_instance_get(name) - @association_cache[name.to_sym] + @association_cache[name] end # Set the specified association instance. @@ -172,7 +165,7 @@ module ActiveRecord @association_cache[name] = association end - # Associations are a set of macro-like class methods for tying objects together through + # \Associations are a set of macro-like class methods for tying objects together through # foreign keys. They express relationships like "Project has one Project Manager" # or "Project belongs to a Portfolio". Each macro adds a number of methods to the # class which are specialized according to the collection or association symbol and the @@ -365,11 +358,11 @@ module ActiveRecord # there is some special behavior you should be aware of, mostly involving the saving of # associated objects. # - # You can set the :autosave option on a <tt>has_one</tt>, <tt>belongs_to</tt>, + # You can set the <tt>:autosave</tt> option on a <tt>has_one</tt>, <tt>belongs_to</tt>, # <tt>has_many</tt>, or <tt>has_and_belongs_to_many</tt> association. Setting it # to +true+ will _always_ save the members, whereas setting it to +false+ will - # _never_ save the members. More details about :autosave option is available at - # autosave_association.rb . + # _never_ save the members. More details about <tt>:autosave</tt> option is available at + # AutosaveAssociation. # # === One-to-one associations # @@ -402,7 +395,7 @@ module ActiveRecord # # == Customizing the query # - # Associations are built from <tt>Relation</tt>s, and you can use the <tt>Relation</tt> syntax + # \Associations are built from <tt>Relation</tt>s, and you can use the <tt>Relation</tt> syntax # to customize them. For example, to add a condition: # # class Blog < ActiveRecord::Base @@ -568,6 +561,8 @@ module ActiveRecord # @group.avatars << Avatar.new # this would work if User belonged_to Avatar rather than the other way around # @group.avatars.delete(@group.avatars.last) # so would this # + # == Setting Inverses + # # If you are using a +belongs_to+ on the join model, it is a good idea to set the # <tt>:inverse_of</tt> option on the +belongs_to+, which will mean that the following example # works correctly (where <tt>tags</tt> is a +has_many+ <tt>:through</tt> association): @@ -584,7 +579,27 @@ module ActiveRecord # belongs_to :tag, inverse_of: :taggings # end # - # == Nested Associations + # If you do not set the <tt>:inverse_of</tt> record, the association will + # do its best to match itself up with the correct inverse. Automatic + # inverse detection only works on <tt>has_many</tt>, <tt>has_one</tt>, and + # <tt>belongs_to</tt> associations. + # + # Extra options on the associations, as defined in the + # <tt>AssociationReflection::INVALID_AUTOMATIC_INVERSE_OPTIONS</tt> constant, will + # also prevent the association's inverse from being found automatically. + # + # The automatic guessing of the inverse association uses a heuristic based + # on the name of the class, so it may not work for all associations, + # especially the ones with non-standard names. + # + # You can turn off the automatic detection of inverse associations by setting + # the <tt>:inverse_of</tt> option to <tt>false</tt> like so: + # + # class Taggable < ActiveRecord::Base + # belongs_to :tag, inverse_of: false + # end + # + # == Nested \Associations # # You can actually specify *any* association with the <tt>:through</tt> option, including an # association which has a <tt>:through</tt> option itself. For example: @@ -627,7 +642,7 @@ module ActiveRecord # add a <tt>Commenter</tt> in the example above, there would be no way to tell how to set up the # intermediate <tt>Post</tt> and <tt>Comment</tt> objects. # - # == Polymorphic Associations + # == Polymorphic \Associations # # Polymorphic associations on models are not restricted on what types of models they # can be associated with. Rather, they specify an interface that a +has_many+ association @@ -789,7 +804,7 @@ module ActiveRecord # For example if all the addressables are either of class Person or Company then a total # of 3 queries will be executed. The list of addressable types to load is determined on # the back of the addresses loaded. This is not supported if Active Record has to fallback - # to the previous implementation of eager loading and will raise ActiveRecord::EagerLoadPolymorphicError. + # to the previous implementation of eager loading and will raise <tt>ActiveRecord::EagerLoadPolymorphicError</tt>. # The reason is that the parent model's type is a column value so its corresponding table # name cannot be put in the +FROM+/+JOIN+ clauses of that query. # @@ -1024,7 +1039,7 @@ module ActiveRecord # An empty array is returned if none are found. # [collection<<(object, ...)] # Adds one or more objects to the collection by setting their foreign keys to the collection's primary key. - # Note that this operation instantly fires update sql without waiting for the save or update call on the + # Note that this operation instantly fires update SQL without waiting for the save or update call on the # parent object, unless the parent object is a new record. # [collection.delete(object, ...)] # Removes one or more objects from the collection by setting their foreign keys to +NULL+. @@ -1060,10 +1075,10 @@ module ActiveRecord # [collection.size] # Returns the number of associated objects. # [collection.find(...)] - # Finds an associated object according to the same rules as ActiveRecord::Base.find. + # Finds an associated object according to the same rules as <tt>ActiveRecord::Base.find</tt>. # [collection.exists?(...)] # Checks whether an associated object with the given conditions exists. - # Uses the same rules as ActiveRecord::Base.exists?. + # Uses the same rules as <tt>ActiveRecord::Base.exists?</tt>. # [collection.build(attributes = {}, ...)] # Returns one or more new objects of the collection type that have been instantiated # with +attributes+ and linked to this object through a foreign key, but have not yet @@ -1073,13 +1088,16 @@ module ActiveRecord # with +attributes+, linked to this object through a foreign key, and that has already # been saved (if it passed the validation). *Note*: This only works if the base model # already exists in the DB, not if it is a new (unsaved) record! + # [collection.create!(attributes = {})] + # Does the same as <tt>collection.create</tt>, but raises <tt>ActiveRecord::RecordInvalid</tt> + # if the record is invalid. # # (*Note*: +collection+ is replaced with the symbol passed as the first argument, so # <tt>has_many :clients</tt> would add among others <tt>clients.empty?</tt>.) # # === Example # - # Example: A Firm class declares <tt>has_many :clients</tt>, which will add: + # A <tt>Firm</tt> class declares <tt>has_many :clients</tt>, which will add: # * <tt>Firm#clients</tt> (similar to <tt>Client.where(firm_id: id)</tt>) # * <tt>Firm#clients<<</tt> # * <tt>Firm#clients.delete</tt> @@ -1094,6 +1112,7 @@ module ActiveRecord # * <tt>Firm#clients.exists?(name: 'ACME')</tt> (similar to <tt>Client.exists?(name: 'ACME', firm_id: firm.id)</tt>) # * <tt>Firm#clients.build</tt> (similar to <tt>Client.new("firm_id" => id)</tt>) # * <tt>Firm#clients.create</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save; c</tt>) + # * <tt>Firm#clients.create!</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save!</tt>) # The declaration can also include an options hash to specialize the behavior of the association. # # === Options @@ -1112,8 +1131,8 @@ module ActiveRecord # Controls what happens to the associated objects when # their owner is destroyed. Note that these are implemented as # callbacks, and Rails executes callbacks in order. Therefore, other - # similar callbacks may affect the :dependent behavior, and the - # :dependent behavior may affect other callbacks. + # similar callbacks may affect the <tt>:dependent</tt> behavior, and the + # <tt>:dependent</tt> behavior may affect other callbacks. # # * <tt>:destroy</tt> causes all the associated objects to also be destroyed. # * <tt>:delete_all</tt> causes all the associated objects to be deleted directly from the database (so callbacks will not be executed). @@ -1159,8 +1178,8 @@ module ActiveRecord # If true, always save the associated objects or destroy them if marked for destruction, # when saving the parent object. If false, never save or destroy the associated objects. # By default, only save associated objects that are new records. This option is implemented as a - # before_save callback. Because callbacks are run in the order they are defined, associated objects - # may need to be explicitly saved in any user-defined before_save callbacks. + # +before_save+ callback. Because callbacks are run in the order they are defined, associated objects + # may need to be explicitly saved in any user-defined +before_save+ callbacks. # # Note that <tt>accepts_nested_attributes_for</tt> sets <tt>:autosave</tt> to <tt>true</tt>. # [:inverse_of] @@ -1179,13 +1198,14 @@ module ActiveRecord # has_many :reports, -> { readonly } # has_many :subscribers, through: :subscriptions, source: :user def has_many(name, scope = nil, options = {}, &extension) - Builder::HasMany.build(self, name, scope, options, &extension) + reflection = Builder::HasMany.build(self, name, scope, options, &extension) + Reflection.add_reflection self, name, reflection end # Specifies a one-to-one association with another class. This method should only be used # if the other class contains the foreign key. If the current class contains the foreign key, # then you should use +belongs_to+ instead. See also ActiveRecord::Associations::ClassMethods's overview - # on when to use has_one and when to use belongs_to. + # on when to use +has_one+ and when to use +belongs_to+. # # The following methods for retrieval and query of a single associated object will be added: # @@ -1282,7 +1302,8 @@ module ActiveRecord # has_one :club, through: :membership # has_one :primary_address, -> { where primary: true }, through: :addressables, source: :addressable def has_one(name, scope = nil, options = {}) - Builder::HasOne.build(self, name, scope, options) + reflection = Builder::HasOne.build(self, name, scope, options) + Reflection.add_reflection self, name, reflection end # Specifies a one-to-one association with another class. This method should only be used @@ -1353,7 +1374,7 @@ module ActiveRecord # class is created and decremented when it's destroyed. This requires that a column # named <tt>#{table_name}_count</tt> (such as +comments_count+ for a belonging Comment class) # is used on the associate class (such as a Post class) - that is the migration for - # <tt>#{table_name}_count</tt> is created on the associate class (such that Post.comments_count will + # <tt>#{table_name}_count</tt> is created on the associate class (such that <tt>Post.comments_count</tt> will # return the count cached, see note below). You can also specify a custom counter # cache column by providing a column name instead of a +true+/+false+ value to this # option (e.g., <tt>counter_cache: :my_custom_counter</tt>.) @@ -1394,7 +1415,8 @@ module ActiveRecord # belongs_to :company, touch: true # belongs_to :company, touch: :employees_last_updated_at def belongs_to(name, scope = nil, options = {}) - Builder::BelongsTo.build(self, name, scope, options) + reflection = Builder::BelongsTo.build(self, name, scope, options) + Reflection.add_reflection self, name, reflection end # Specifies a many-to-many relationship with another class. This associates two classes via an @@ -1435,7 +1457,7 @@ module ActiveRecord # [collection<<(object, ...)] # Adds one or more objects to the collection by creating associations in the join table # (<tt>collection.push</tt> and <tt>collection.concat</tt> are aliases to this method). - # Note that this operation instantly fires update sql without waiting for the save or update call on the + # Note that this operation instantly fires update SQL without waiting for the save or update call on the # parent object, unless the parent object is a new record. # [collection.delete(object, ...)] # Removes one or more objects from the collection by removing their associations from the join table. @@ -1458,10 +1480,10 @@ module ActiveRecord # [collection.find(id)] # Finds an associated object responding to the +id+ and that # meets the condition that it has to be associated with this object. - # Uses the same rules as ActiveRecord::Base.find. + # Uses the same rules as <tt>ActiveRecord::Base.find</tt>. # [collection.exists?(...)] # Checks whether an associated object with the given conditions exists. - # Uses the same rules as ActiveRecord::Base.exists?. + # Uses the same rules as <tt>ActiveRecord::Base.exists?</tt>. # [collection.build(attributes = {})] # Returns a new object of the collection type that has been instantiated # with +attributes+ and linked to this object through the join table, but has not yet been saved. @@ -1531,7 +1553,39 @@ module ActiveRecord # has_and_belongs_to_many :categories, join_table: "prods_cats" # has_and_belongs_to_many :categories, -> { readonly } def has_and_belongs_to_many(name, scope = nil, options = {}, &extension) - Builder::HasAndBelongsToMany.build(self, name, scope, options, &extension) + if scope.is_a?(Hash) + options = scope + scope = nil + end + + builder = Builder::HasAndBelongsToMany.new name, self, options + + join_model = builder.through_model + + middle_reflection = builder.middle_reflection join_model + + Builder::HasMany.define_callbacks self, middle_reflection + Reflection.add_reflection self, middle_reflection.name, middle_reflection + + include Module.new { + class_eval <<-RUBY, __FILE__, __LINE__ + 1 + def destroy_associations + association(:#{middle_reflection.name}).delete_all(:delete_all) + association(:#{name}).reset + super + end + RUBY + } + + hm_options = {} + hm_options[:through] = middle_reflection.name + hm_options[:source] = join_model.right_reflection.name + + [:before_add, :after_add, :before_remove, :after_remove].each do |k| + hm_options[k] = options[k] if options.key? k + end + + has_many name, scope, hm_options, &extension end end end |