diff options
Diffstat (limited to 'activerecord/lib/active_record/associations.rb')
| -rw-r--r-- | activerecord/lib/active_record/associations.rb | 1526 |
1 files changed, 426 insertions, 1100 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb index 73c0900c8b..08fb6bf3c4 100644 --- a/activerecord/lib/active_record/associations.rb +++ b/activerecord/lib/active_record/associations.rb @@ -4,6 +4,7 @@ require 'active_support/core_ext/module/delegation' require 'active_support/core_ext/object/blank' require 'active_support/core_ext/string/conversions' require 'active_support/core_ext/module/remove_method' +require 'active_support/core_ext/class/attribute' module ActiveRecord class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc: @@ -18,32 +19,36 @@ module ActiveRecord end end - class HasManyThroughAssociationPolymorphicError < ActiveRecordError #:nodoc: + class HasManyThroughAssociationPolymorphicSourceError < ActiveRecordError #:nodoc: def initialize(owner_class_name, reflection, source_reflection) super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' on the polymorphic object '#{source_reflection.class_name}##{source_reflection.name}'.") end end + class HasManyThroughAssociationPolymorphicThroughError < ActiveRecordError #:nodoc: + def initialize(owner_class_name, reflection) + super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' which goes through the polymorphic association '#{owner_class_name}##{reflection.through_reflection.name}'.") + end + end + class HasManyThroughAssociationPointlessSourceTypeError < ActiveRecordError #:nodoc: def initialize(owner_class_name, reflection, source_reflection) super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' with a :source_type option if the '#{reflection.through_reflection.class_name}##{source_reflection.name}' is not polymorphic. Try removing :source_type on your association.") end end + class HasOneThroughCantAssociateThroughCollection < ActiveRecordError #:nodoc: + def initialize(owner_class_name, reflection, through_reflection) + super("Cannot have a has_one :through association '#{owner_class_name}##{reflection.name}' where the :through association '#{owner_class_name}##{through_reflection.name}' is a collection. Specify a has_one or belongs_to association in the :through option instead.") + end + end + class HasManyThroughSourceAssociationNotFoundError < ActiveRecordError #:nodoc: def initialize(reflection) through_reflection = reflection.through_reflection source_reflection_names = reflection.source_reflection_names source_associations = reflection.through_reflection.klass.reflect_on_all_associations.collect { |a| a.name.inspect } - super("Could not find the source association(s) #{source_reflection_names.collect(&:inspect).to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)} in model #{through_reflection.klass}. Try 'has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}, :source => <name>'. Is it one of #{source_associations.to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)}?") - end - end - - class HasManyThroughSourceAssociationMacroError < ActiveRecordError #:nodoc: - def initialize(reflection) - through_reflection = reflection.through_reflection - source_reflection = reflection.source_reflection - super("Invalid source reflection macro :#{source_reflection.macro}#{" :through" if source_reflection.options[:through]} for has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}. Use :source to specify the source reflection.") + super("Could not find the source association(s) #{source_reflection_names.collect{ |a| a.inspect }.to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)} in model #{through_reflection.klass}. Try 'has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}, :source => <name>'. Is it one of #{source_associations.to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)}?") end end @@ -65,6 +70,12 @@ module ActiveRecord end end + class HasManyThroughNestedAssociationsAreReadonly < ActiveRecordError #:nodoc + def initialize(owner, reflection) + super("Cannot modify association '#{owner.class.name}##{reflection.name}' because it goes through more than one other association.") + end + end + class HasAndBelongsToManyAssociationWithPrimaryKeyError < ActiveRecordError #:nodoc: def initialize(reflection) super("Primary key is not allowed in a has_and_belongs_to_many join table (#{reflection.options[:join_table]}).") @@ -93,8 +104,8 @@ module ActiveRecord # (has_many, has_one) when there is at least 1 child associated instance. # ex: if @project.tasks.size > 0, DeleteRestrictionError will be raised when trying to destroy @project class DeleteRestrictionError < ActiveRecordError #:nodoc: - def initialize(reflection) - super("Cannot delete record because of dependent #{reflection.name}") + def initialize(name) + super("Cannot delete record because of dependent #{name}") end end @@ -104,44 +115,75 @@ module ActiveRecord # These classes will be loaded when associations are created. # So there is no need to eager load them. - autoload :AssociationCollection, 'active_record/associations/association_collection' - autoload :AssociationProxy, 'active_record/associations/association_proxy' - autoload :BelongsToAssociation, 'active_record/associations/belongs_to_association' + autoload :Association, 'active_record/associations/association' + autoload :SingularAssociation, 'active_record/associations/singular_association' + autoload :CollectionAssociation, 'active_record/associations/collection_association' + autoload :CollectionProxy, 'active_record/associations/collection_proxy' + + 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' - autoload :HasOneThroughAssociation, 'active_record/associations/has_one_through_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' + autoload :HasOneThroughAssociation, 'active_record/associations/has_one_through_association' + autoload :ThroughAssociation, 'active_record/associations/through_association' + + module Builder #:nodoc: + autoload :Association, 'active_record/associations/builder/association' + autoload :SingularAssociation, 'active_record/associations/builder/singular_association' + autoload :CollectionAssociation, 'active_record/associations/builder/collection_association' + + autoload :BelongsTo, 'active_record/associations/builder/belongs_to' + autoload :HasOne, 'active_record/associations/builder/has_one' + autoload :HasMany, 'active_record/associations/builder/has_many' + autoload :HasAndBelongsToMany, 'active_record/associations/builder/has_and_belongs_to_many' + end + + autoload :Preloader, 'active_record/associations/preloader' + autoload :JoinDependency, 'active_record/associations/join_dependency' + autoload :AssociationScope, 'active_record/associations/association_scope' + autoload :AliasTracker, 'active_record/associations/alias_tracker' + autoload :JoinHelper, 'active_record/associations/join_helper' # Clears out the association cache. def clear_association_cache #:nodoc: - self.class.reflect_on_all_associations.to_a.each do |assoc| - instance_variable_set "@#{assoc.name}", nil - end unless self.new_record? + @association_cache.clear if persisted? + end + + # :nodoc: + attr_reader :association_cache + + # Returns the association instance for the given name, instantiating it if it doesn't already exist + def association(name) #:nodoc: + association = association_instance_get(name) + + if association.nil? + reflection = self.class.reflect_on_association(name) + association = reflection.association_class.new(self, reflection) + association_instance_set(name, association) + end + + association end private # Returns the specified association instance if it responds to :loaded?, nil otherwise. def association_instance_get(name) - ivar = "@#{name}" - if instance_variable_defined?(ivar) - association = instance_variable_get(ivar) - association if association.respond_to?(:loaded?) - end + @association_cache[name.to_sym] end # Set the specified association instance. def association_instance_set(name, association) - instance_variable_set("@#{name}", association) + @association_cache[name] = association end - # 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 + # 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 # options hash. It works much the same way as Ruby's own <tt>attr*</tt> - # methods. + # methods. # # class Project < ActiveRecord::Base # belongs_to :portfolio @@ -150,7 +192,7 @@ module ActiveRecord # has_and_belongs_to_many :categories # end # - # The project class now has the following methods (and more) to ease the traversal and + # The project class now has the following methods (and more) to ease the traversal and # manipulation of its relationships: # * <tt>Project#portfolio, Project#portfolio=(portfolio), Project#portfolio.nil?</tt> # * <tt>Project#project_manager, Project#project_manager=(project_manager), Project#project_manager.nil?,</tt> @@ -162,8 +204,8 @@ module ActiveRecord # # === A word of warning # - # Don't create associations that have the same name as instance methods of - # <tt>ActiveRecord::Base</tt>. Since the association adds a method with that name to + # Don't create associations that have the same name as instance methods of + # <tt>ActiveRecord::Base</tt>. Since the association adds a method with that name to # its model, it will override the inherited method and break things. # For instance, +attributes+ and +connection+ would be bad choices for association names. # @@ -177,7 +219,7 @@ module ActiveRecord # other=(other) | X | X | X # build_other(attributes={}) | X | | X # create_other(attributes={}) | X | | X - # other.create!(attributes={}) | | | X + # create_other!(attributes={}) | X | | X # # ===Collection associations (one-to-many / many-to-many) # | | | has_many @@ -200,10 +242,9 @@ module ActiveRecord # others.empty? | X | X | X # others.clear | X | X | X # others.delete(other,other,...) | X | X | X - # others.delete_all | X | X | + # others.delete_all | X | X | X # others.destroy_all | X | X | X # others.find(*args) | X | X | X - # others.find_first | X | | # others.exists? | X | X | X # others.uniq | X | X | X # others.reset | X | X | X @@ -274,7 +315,7 @@ module ActiveRecord # # == Is it a +belongs_to+ or +has_one+ association? # - # Both express a 1-1 relationship. The difference is mostly where to place the foreign + # Both express a 1-1 relationship. The difference is mostly where to place the foreign # key, which goes on the table for the class declaring the +belongs_to+ relationship. # # class User < ActiveRecord::Base @@ -304,43 +345,49 @@ module ActiveRecord # # == Unsaved objects and associations # - # You can manipulate objects and associations before they are saved to the database, but - # there is some special behavior you should be aware of, mostly involving the saving of + # You can manipulate objects and associations before they are saved to the database, but + # 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>, # <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. + # _never_ save the members. More details about :autosave option is available at + # autosave_association.rb . # # === One-to-one associations # - # * Assigning an object to a +has_one+ association automatically saves that object and - # the object being replaced (if there is one), in order to update their primary - # keys - except if the parent object is unsaved (<tt>new_record? == true</tt>). - # * If either of these saves fail (due to one of the objects being invalid) the assignment - # statement returns +false+ and the assignment is cancelled. - # * If you wish to assign an object to a +has_one+ association without saving it, - # use the <tt>association.build</tt> method (documented below). - # * Assigning an object to a +belongs_to+ association does not save the object, since - # the foreign key field belongs on the parent. It does not save the parent either. + # * Assigning an object to a +has_one+ association automatically saves that object and + # the object being replaced (if there is one), in order to update their foreign + # keys - except if the parent object is unsaved (<tt>new_record? == true</tt>). + # * If either of these saves fail (due to one of the objects being invalid), an + # <tt>ActiveRecord::RecordNotSaved</tt> exception is raised and the assignment is + # cancelled. + # * If you wish to assign an object to a +has_one+ association without saving it, + # use the <tt>build_association</tt> method (documented below). The object being + # replaced will still be saved to update its foreign key. + # * Assigning an object to a +belongs_to+ association does not save the object, since + # the foreign key field belongs on the parent. It does not save the parent either. # # === Collections # - # * Adding an object to a collection (+has_many+ or +has_and_belongs_to_many+) automatically - # saves that object, except if the parent object (the owner of the collection) is not yet - # stored in the database. - # * If saving any of the objects being added to a collection (via <tt>push</tt> or similar) - # fails, then <tt>push</tt> returns +false+. - # * You can add an object to a collection without automatically saving it by using the - # <tt>collection.build</tt> method (documented below). - # * All unsaved (<tt>new_record? == true</tt>) members of the collection are automatically - # saved when the parent is saved. + # * Adding an object to a collection (+has_many+ or +has_and_belongs_to_many+) automatically + # saves that object, except if the parent object (the owner of the collection) is not yet + # stored in the database. + # * If saving any of the objects being added to a collection (via <tt>push</tt> or similar) + # fails, then <tt>push</tt> returns +false+. + # * If saving fails while replacing the collection (via <tt>association=</tt>), an + # <tt>ActiveRecord::RecordNotSaved</tt> exception is raised and the assignment is + # cancelled. + # * You can add an object to a collection without automatically saving it by using the + # <tt>collection.build</tt> method (documented below). + # * All unsaved (<tt>new_record? == true</tt>) members of the collection are automatically + # saved when the parent is saved. # # === Association callbacks # - # Similar to the normal callbacks that hook into the lifecycle of an Active Record object, - # you can also define callbacks that get triggered when you add an object to or remove an + # Similar to the normal callbacks that hook into the life cycle of an Active Record object, + # you can also define callbacks that get triggered when you add an object to or remove an # object from an association collection. # # class Project @@ -354,20 +401,20 @@ module ActiveRecord # It's possible to stack callbacks by passing them as an array. Example: # # class Project - # has_and_belongs_to_many :developers, + # has_and_belongs_to_many :developers, # :after_add => [:evaluate_velocity, Proc.new { |p, d| p.shipping_date = Time.now}] # end # # Possible callbacks are: +before_add+, +after_add+, +before_remove+ and +after_remove+. # - # Should any of the +before_add+ callbacks throw an exception, the object does not get - # added to the collection. Same with the +before_remove+ callbacks; if an exception is + # Should any of the +before_add+ callbacks throw an exception, the object does not get + # added to the collection. Same with the +before_remove+ callbacks; if an exception is # thrown the object doesn't get removed. # # === Association extensions # - # The proxy objects that control the access to associations can be extended through anonymous - # modules. This is especially beneficial for adding new finders, creators, and other + # The proxy objects that control the access to associations can be extended through anonymous + # modules. This is especially beneficial for adding new finders, creators, and other # factory-type methods that are only used as part of this association. # # class Account < ActiveRecord::Base @@ -383,8 +430,8 @@ module ActiveRecord # person.first_name # => "David" # person.last_name # => "Heinemeier Hansson" # - # If you need to share the same extensions between many associations, you can use a named - # extension module. + # If you need to share the same extensions between many associations, you can use a named + # extension module. # # module FindOrCreateByNameExtension # def find_or_create_by_name(name) @@ -401,10 +448,10 @@ module ActiveRecord # has_many :people, :extend => FindOrCreateByNameExtension # end # - # If you need to use multiple named extension modules, you can specify an array of modules + # If you need to use multiple named extension modules, you can specify an array of modules # with the <tt>:extend</tt> option. - # In the case of name conflicts between methods in the modules, methods in modules later - # in the array supercede those earlier in the array. + # In the case of name conflicts between methods in the modules, methods in modules later + # in the array supercede those earlier in the array. # # class Account < ActiveRecord::Base # has_many :people, :extend => [FindOrCreateByNameExtension, FindRecentExtension] @@ -415,13 +462,13 @@ module ActiveRecord # # * +proxy_owner+ - Returns the object the association is part of. # * +proxy_reflection+ - Returns the reflection object that describes the association. - # * +proxy_target+ - Returns the associated object for +belongs_to+ and +has_one+, or + # * +proxy_target+ - Returns the associated object for +belongs_to+ and +has_one+, or # the collection of associated objects for +has_many+ and +has_and_belongs_to_many+. # # === Association Join Models # - # Has Many associations can be configured with the <tt>:through</tt> option to use an - # explicit join model to retrieve the data. This operates similarly to a + # Has Many associations can be configured with the <tt>:through</tt> option to use an + # explicit join model to retrieve the data. This operates similarly to a # +has_and_belongs_to_many+ association. The advantage is that you're able to add validations, # callbacks, and extra attributes on the join model. Consider the following schema: # @@ -479,17 +526,76 @@ module ActiveRecord # @group.users.collect { |u| u.avatar }.flatten # select all avatars for all users in the group # @group.avatars # selects all avatars by going through the User join model. # - # An important caveat with going through +has_one+ or +has_many+ associations on the - # join model is that these associations are *read-only*. For example, the following + # An important caveat with going through +has_one+ or +has_many+ associations on the + # join model is that these associations are *read-only*. For example, the following # would not work following the previous example: # # @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 # + # 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): + # + # @post = Post.first + # @tag = @post.tags.build :name => "ruby" + # @tag.save + # + # The last line ought to save the through record (a <tt>Taggable</tt>). This will only work if the + # <tt>:inverse_of</tt> is set: + # + # class Taggable < ActiveRecord::Base + # belongs_to :post + # belongs_to :tag, :inverse_of => :taggings + # 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: + # + # class Author < ActiveRecord::Base + # has_many :posts + # has_many :comments, :through => :posts + # has_many :commenters, :through => :comments + # end + # + # class Post < ActiveRecord::Base + # has_many :comments + # end + # + # class Comment < ActiveRecord::Base + # belongs_to :commenter + # end + # + # @author = Author.first + # @author.commenters # => People who commented on posts written by the author + # + # An equivalent way of setting up this association this would be: + # + # class Author < ActiveRecord::Base + # has_many :posts + # has_many :commenters, :through => :posts + # end + # + # class Post < ActiveRecord::Base + # has_many :comments + # has_many :commenters, :through => :comments + # end + # + # class Comment < ActiveRecord::Base + # belongs_to :commenter + # end + # + # When using nested association, you will not be able to modify the association because there + # is not enough information to know what modification to make. For example, if you tried to + # 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 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 + # 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 # must adhere to. # # class Asset < ActiveRecord::Base @@ -502,15 +608,15 @@ module ActiveRecord # # @asset.attachable = @post # - # This works by using a type column in addition to a foreign key to specify the associated - # record. In the Asset example, you'd need an +attachable_id+ integer column and an + # This works by using a type column in addition to a foreign key to specify the associated + # record. In the Asset example, you'd need an +attachable_id+ integer column and an # +attachable_type+ string column. # - # Using polymorphic associations in combination with single table inheritance (STI) is - # a little tricky. In order for the associations to work as expected, ensure that you - # store the base model for the STI models in the type column of the polymorphic + # Using polymorphic associations in combination with single table inheritance (STI) is + # a little tricky. In order for the associations to work as expected, ensure that you + # store the base model for the STI models in the type column of the polymorphic # association. To continue with the asset example above, suppose there are guest posts - # and member posts that use the posts table for STI. In this case, there must be a +type+ + # and member posts that use the posts table for STI. In this case, there must be a +type+ # column in the posts table. # # class Asset < ActiveRecord::Base @@ -534,8 +640,8 @@ module ActiveRecord # # == Caching # - # All of the methods are built on a simple caching principle that will keep the result - # of the last query around unless specifically instructed not to. The cache is even + # All of the methods are built on a simple caching principle that will keep the result + # of the last query around unless specifically instructed not to. The cache is even # shared across methods to make it even cheaper to use the macro-added methods without # worrying too much about performance at the first go. # @@ -547,9 +653,9 @@ module ActiveRecord # # == Eager loading of associations # - # Eager loading is a way to find objects of a certain class and a number of named associations. - # This is one of the easiest ways of to prevent the dreaded 1+N problem in which fetching 100 - # posts that each need to display their author triggers 101 database queries. Through the + # Eager loading is a way to find objects of a certain class and a number of named associations. + # This is one of the easiest ways of to prevent the dreaded 1+N problem in which fetching 100 + # posts that each need to display their author triggers 101 database queries. Through the # use of eager loading, the 101 queries can be reduced to 2. # # class Post < ActiveRecord::Base @@ -565,54 +671,54 @@ module ActiveRecord # puts "Last comment on: " + post.comments.first.created_on # end # - # To iterate over these one hundred posts, we'll generate 201 database queries. Let's + # To iterate over these one hundred posts, we'll generate 201 database queries. Let's # first just optimize it for retrieving the author: # # for post in Post.find(:all, :include => :author) # - # This references the name of the +belongs_to+ association that also used the <tt>:author</tt> - # symbol. After loading the posts, find will collect the +author_id+ from each one and load - # all the referenced authors with one query. Doing so will cut down the number of queries + # This references the name of the +belongs_to+ association that also used the <tt>:author</tt> + # symbol. After loading the posts, find will collect the +author_id+ from each one and load + # all the referenced authors with one query. Doing so will cut down the number of queries # from 201 to 102. # # We can improve upon the situation further by referencing both associations in the finder with: # # for post in Post.find(:all, :include => [ :author, :comments ]) # - # This will load all comments with a single query. This reduces the total number of queries - # to 3. More generally the number of queries will be 1 plus the number of associations + # This will load all comments with a single query. This reduces the total number of queries + # to 3. More generally the number of queries will be 1 plus the number of associations # named (except if some of the associations are polymorphic +belongs_to+ - see below). # # To include a deep hierarchy of associations, use a hash: # # for post in Post.find(:all, :include => [ :author, { :comments => { :author => :gravatar } } ]) # - # That'll grab not only all the comments but all their authors and gravatar pictures. - # You can mix and match symbols, arrays and hashes in any combination to describe the + # That'll grab not only all the comments but all their authors and gravatar pictures. + # You can mix and match symbols, arrays and hashes in any combination to describe the # associations you want to load. # - # All of this power shouldn't fool you into thinking that you can pull out huge amounts - # of data with no performance penalty just because you've reduced the number of queries. - # The database still needs to send all the data to Active Record and it still needs to - # be processed. So it's no catch-all for performance problems, but it's a great way to + # All of this power shouldn't fool you into thinking that you can pull out huge amounts + # of data with no performance penalty just because you've reduced the number of queries. + # The database still needs to send all the data to Active Record and it still needs to + # be processed. So it's no catch-all for performance problems, but it's a great way to # cut down on the number of queries in a situation as the one described above. # - # Since only one table is loaded at a time, conditions or orders cannot reference tables - # other than the main one. If this is the case Active Record falls back to the previously + # Since only one table is loaded at a time, conditions or orders cannot reference tables + # other than the main one. If this is the case Active Record falls back to the previously # used LEFT OUTER JOIN based strategy. For example # - # Post.find(:all, :include => [ :author, :comments ], :conditions => ['comments.approved = ?', true]) + # Post.includes([:author, :comments]).where(['comments.approved = ?', true]).all # - # This will result in a single SQL query with joins along the lines of: + # This will result in a single SQL query with joins along the lines of: # <tt>LEFT OUTER JOIN comments ON comments.post_id = posts.id</tt> and - # <tt>LEFT OUTER JOIN authors ON authors.id = posts.author_id</tt>. Note that using conditions + # <tt>LEFT OUTER JOIN authors ON authors.id = posts.author_id</tt>. Note that using conditions # like this can have unintended consequences. - # In the above example posts with no approved comments are not returned at all, because - # the conditions apply to the SQL statement as a whole and not just to the association. + # In the above example posts with no approved comments are not returned at all, because + # the conditions apply to the SQL statement as a whole and not just to the association. # You must disambiguate column references for this fallback to happen, for example # <tt>:order => "author.name DESC"</tt> will work but <tt>:order => "name DESC"</tt> will not. # - # If you do want eager load only some members of an association it is usually more natural + # If you do want eager load only some members of an association it is usually more natural # to <tt>:include</tt> an association which has conditions defined on it: # # class Post < ActiveRecord::Base @@ -621,10 +727,10 @@ module ActiveRecord # # Post.find(:all, :include => :approved_comments) # - # This will load posts and eager load the +approved_comments+ association, which contains + # This will load posts and eager load the +approved_comments+ association, which contains # only those comments that have been approved. # - # If you eager load an association with a specified <tt>:limit</tt> option, it will be ignored, + # If you eager load an association with a specified <tt>:limit</tt> option, it will be ignored, # returning all the associated objects: # # class Picture < ActiveRecord::Base @@ -633,7 +739,7 @@ module ActiveRecord # # Picture.find(:first, :include => :most_recent_comments).most_recent_comments # => returns all associated comments. # - # When eager loaded, conditions are interpolated in the context of the model class, not + # When eager loaded, conditions are interpolated in the context of the model class, not # the model instance. Conditions are lazily interpolated before the actual model exists. # # Eager loading is supported with polymorphic associations. @@ -646,20 +752,20 @@ module ActiveRecord # # Address.find(:all, :include => :addressable) # - # This will execute one query to load the addresses and load the addressables with one + # This will execute one query to load the addresses and load the addressables with one # query per addressable type. - # 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 + # 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. - # The reason is that the parent model's type is a column value so its corresponding table + # to the previous implementation of eager loading and will raise ActiveRecord::EagerLoadPolymorphicError. + # 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. # # == Table Aliasing # - # Active Record uses table aliasing in the case that a table is referenced multiple times - # in a join. If a table is referenced only once, the standard table name is used. The - # second time, the table is aliased as <tt>#{reflection_name}_#{parent_table_name}</tt>. + # Active Record uses table aliasing in the case that a table is referenced multiple times + # in a join. If a table is referenced only once, the standard table name is used. The + # second time, the table is aliased as <tt>#{reflection_name}_#{parent_table_name}</tt>. # Indexes are appended for any more successive uses of the table name. # # Post.find :all, :joins => :comments @@ -693,7 +799,7 @@ module ActiveRecord # INNER JOIN categories_posts posts_categories_join INNER JOIN posts posts_categories # INNER JOIN categories_posts categories_posts_join INNER JOIN categories categories_posts_2 # - # If you wish to specify your own custom joins using a <tt>:joins</tt> option, those table + # If you wish to specify your own custom joins using a <tt>:joins</tt> option, those table # names will take precedence over the eager associations: # # Post.find :all, :joins => :comments, :joins => "inner join comments ..." @@ -703,7 +809,7 @@ module ActiveRecord # INNER JOIN comments special_comments_posts ... # INNER JOIN comments ... # - # Table aliases are automatically truncated according to the maximum length of table identifiers + # Table aliases are automatically truncated according to the maximum length of table identifiers # according to the specific database. # # == Modules @@ -720,9 +826,9 @@ module ActiveRecord # end # end # - # When <tt>Firm#clients</tt> is called, it will in turn call + # When <tt>Firm#clients</tt> is called, it will in turn call # <tt>MyApplication::Business::Client.find_all_by_firm_id(firm.id)</tt>. - # If you want to associate with a class in another module scope, this can be done by + # If you want to associate with a class in another module scope, this can be done by # specifying the complete class name. # # module MyApplication @@ -739,7 +845,7 @@ module ActiveRecord # # == Bi-directional associations # - # When you specify an association there is usually an association on the associated model + # When you specify an association there is usually an association on the associated model # that specifies the same relationship in reverse. For example, with the following models: # # class Dungeon < ActiveRecord::Base @@ -755,10 +861,10 @@ module ActiveRecord # belongs_to :dungeon # end # - # The +traps+ association on +Dungeon+ and the the +dungeon+ association on +Trap+ are - # the inverse of each other and the inverse of the +dungeon+ association on +EvilWizard+ + # The +traps+ association on +Dungeon+ and the +dungeon+ association on +Trap+ are + # the inverse of each other and the inverse of the +dungeon+ association on +EvilWizard+ # is the +evil_wizard+ association on +Dungeon+ (and vice-versa). By default, - # Active Record doesn't know anything about these inverse relationships and so no object + # Active Record doesn't know anything about these inverse relationships and so no object # loading optimisation is possible. For example: # # d = Dungeon.first @@ -767,10 +873,10 @@ module ActiveRecord # d.level = 10 # d.level == t.dungeon.level # => false # - # The +Dungeon+ instances +d+ and <tt>t.dungeon</tt> in the above example refer to - # the same object data from the database, but are actually different in-memory copies + # The +Dungeon+ instances +d+ and <tt>t.dungeon</tt> in the above example refer to + # the same object data from the database, but are actually different in-memory copies # of that data. Specifying the <tt>:inverse_of</tt> option on associations lets you tell - # Active Record about inverse relationships and it will optimise object loading. For + # Active Record about inverse relationships and it will optimise object loading. For # example, if we changed our model definitions to: # # class Dungeon < ActiveRecord::Base @@ -786,7 +892,7 @@ module ActiveRecord # belongs_to :dungeon, :inverse_of => :evil_wizard # end # - # Then, from our code snippet above, +d+ and <tt>t.dungeon</tt> are actually the same + # Then, from our code snippet above, +d+ and <tt>t.dungeon</tt> are actually the same # in-memory instance and our final <tt>d.level == t.dungeon.level</tt> will return +true+. # # There are limitations to <tt>:inverse_of</tt> support: @@ -795,14 +901,81 @@ module ActiveRecord # * does not work with <tt>:polymorphic</tt> associations. # * for +belongs_to+ associations +has_many+ inverse associations are ignored. # + # == Deleting from associations + # + # === Dependent associations + # + # +has_many+, +has_one+ and +belongs_to+ associations support the <tt>:dependent</tt> option. + # This allows you to specify that associated records should be deleted when the owner is + # deleted. + # + # For example: + # + # class Author + # has_many :posts, :dependent => :destroy + # end + # Author.find(1).destroy # => Will destroy all of the author's posts, too + # + # The <tt>:dependent</tt> option can have different values which specify how the deletion + # is done. For more information, see the documentation for this option on the different + # specific association types. + # + # === Delete or destroy? + # + # +has_many+ and +has_and_belongs_to_many+ associations have the methods <tt>destroy</tt>, + # <tt>delete</tt>, <tt>destroy_all</tt> and <tt>delete_all</tt>. + # + # For +has_and_belongs_to_many+, <tt>delete</tt> and <tt>destroy</tt> are the same: they + # cause the records in the join table to be removed. + # + # For +has_many+, <tt>destroy</tt> will always call the <tt>destroy</tt> method of the + # record(s) being removed so that callbacks are run. However <tt>delete</tt> will either + # do the deletion according to the strategy specified by the <tt>:dependent</tt> option, or + # if no <tt>:dependent</tt> option is given, then it will follow the default strategy. + # The default strategy is <tt>:nullify</tt> (set the foreign keys to <tt>nil</tt>), except for + # +has_many+ <tt>:through</tt>, where the default strategy is <tt>delete_all</tt> (delete + # the join records, without running their callbacks). + # + # There is also a <tt>clear</tt> method which is the same as <tt>delete_all</tt>, except that + # it returns the association rather than the records which have been deleted. + # + # === What gets deleted? + # + # There is a potential pitfall here: +has_and_belongs_to_many+ and +has_many+ <tt>:through</tt> + # associations have records in join tables, as well as the associated records. So when we + # call one of these deletion methods, what exactly should be deleted? + # + # The answer is that it is assumed that deletion on an association is about removing the + # <i>link</i> between the owner and the associated object(s), rather than necessarily the + # associated objects themselves. So with +has_and_belongs_to_many+ and +has_many+ + # <tt>:through</tt>, the join records will be deleted, but the associated records won't. + # + # This makes sense if you think about it: if you were to call <tt>post.tags.delete(Tag.find_by_name('food'))</tt> + # you would want the 'food' tag to be unlinked from the post, rather than for the tag itself + # to be removed from the database. + # + # However, there are examples where this strategy doesn't make sense. For example, suppose + # a person has many projects, and each project has many tasks. If we deleted one of a person's + # tasks, we would probably not want the project to be deleted. In this scenario, the delete method + # won't actually work: it can only be used if the association on the join model is a + # +belongs_to+. In other situations you are expected to perform operations directly on + # either the associated records or the <tt>:through</tt> association. + # + # With a regular +has_many+ there is no distinction between the "associated records" + # and the "link", so there is only one choice for what gets deleted. + # + # With +has_and_belongs_to_many+ and +has_many+ <tt>:through</tt>, if you want to delete the + # associated records themselves, you can always do something along the lines of + # <tt>person.tasks.each(&:destroy)</tt>. + # # == Type safety with <tt>ActiveRecord::AssociationTypeMismatch</tt> # - # If you attempt to assign an object to an association that doesn't match the inferred + # If you attempt to assign an object to an association that doesn't match the inferred # or specified <tt>:class_name</tt>, you'll get an <tt>ActiveRecord::AssociationTypeMismatch</tt>. # # == Options # - # All of the association macros can be specialized through options. This makes cases + # All of the association macros can be specialized through options. This makes cases # more complex than the simple and guessable ones possible. module ClassMethods # Specifies a one-to-many association. The following methods for retrieval and query of @@ -813,12 +986,16 @@ 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. # [collection.delete(object, ...)] # Removes one or more objects from the collection by setting their foreign keys to +NULL+. # Objects will be in addition destroyed if they're associated with <tt>:dependent => :destroy</tt>, # and deleted if they're associated with <tt>:dependent => :delete_all</tt>. + # + # If the <tt>:through</tt> option is used, then the join records are deleted (rather than + # nullified) by default, but you can specify <tt>:dependent => :destroy</tt> or + # <tt>:dependent => :nullify</tt> to override this. # [collection=objects] # Replaces the collections content by deleting and adding objects as appropriate. If the <tt>:through</tt> # option is true callbacks in the join models are triggered except destroy callbacks, since deletion is @@ -874,24 +1051,24 @@ module ActiveRecord # * <tt>Firm#clients.create</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save; c</tt>) # The declaration can also include an options hash to specialize the behavior of the association. # - # === Supported options + # === Options # [:class_name] # Specify the class name of the association. Use it only if that name can't be inferred - # from the association name. So <tt>has_many :products</tt> will by default be linked - # to the Product class, but if the real class name is SpecialProduct, you'll have to + # from the association name. So <tt>has_many :products</tt> will by default be linked + # to the Product class, but if the real class name is SpecialProduct, you'll have to # specify it with this option. # [:conditions] # Specify the conditions that the associated objects must meet in order to be included as a +WHERE+ - # SQL fragment, such as <tt>price > 5 AND name LIKE 'B%'</tt>. Record creations from - # the association are scoped if a hash is used. - # <tt>has_many :posts, :conditions => {:published => true}</tt> will create published + # SQL fragment, such as <tt>price > 5 AND name LIKE 'B%'</tt>. Record creations from + # the association are scoped if a hash is used. + # <tt>has_many :posts, :conditions => {:published => true}</tt> will create published # posts with <tt>@blog.posts.create</tt> or <tt>@blog.posts.build</tt>. # [:order] # Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment, # such as <tt>last_name, first_name DESC</tt>. # [:foreign_key] # Specify the foreign key used for the association. By default this is guessed to be the name - # of this class in lower-case and "_id" suffixed. So a Person class that makes a +has_many+ + # of this class in lower-case and "_id" suffixed. So a Person class that makes a +has_many+ # association will use "person_id" as the default <tt>:foreign_key</tt>. # [:primary_key] # Specify the method that returns the primary key used for the association. By default this is +id+. @@ -902,15 +1079,17 @@ module ActiveRecord # objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. If set to # <tt>:restrict</tt> this object cannot be deleted if it has any associated object. # - # *Warning:* This option is ignored when used with <tt>:through</tt> option. + # If using with the <tt>:through</tt> option, the association on the join model must be + # a +belongs_to+, and the records which get deleted are the join records, rather than + # the associated records. # # [:finder_sql] # Specify a complete SQL statement to fetch the association. This is a good way to go for complex - # associations that depend on multiple tables. Note: When this option is used, +find_in_collection+ + # associations that depend on multiple tables. Note: When this option is used, +find_in_collection+ # is _not_ added. # [:counter_sql] # Specify a complete SQL statement to fetch the size of the association. If <tt>:finder_sql</tt> is - # specified but not <tt>:counter_sql</tt>, <tt>:counter_sql</tt> will be generated by + # specified but not <tt>:counter_sql</tt>, <tt>:counter_sql</tt> will be generated by # replacing <tt>SELECT ... FROM</tt> with <tt>SELECT COUNT(*) FROM</tt>. # [:extend] # Specify a named module for extending the proxy. See "Association extensions". @@ -919,30 +1098,38 @@ module ActiveRecord # [:group] # An attribute name by which the result should be grouped. Uses the <tt>GROUP BY</tt> SQL-clause. # [:having] - # Combined with +:group+ this can be used to filter the records that a <tt>GROUP BY</tt> + # Combined with +:group+ this can be used to filter the records that a <tt>GROUP BY</tt> # returns. Uses the <tt>HAVING</tt> SQL-clause. # [:limit] # An integer determining the limit on the number of rows that should be returned. # [:offset] - # An integer determining the offset from where the rows should be fetched. So at 5, + # An integer determining the offset from where the rows should be fetched. So at 5, # it would skip the first 4 rows. # [:select] - # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if - # you, for example, want to do a join but not include the joined columns. Do not forget + # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if + # you, for example, want to do a join but not include the joined columns. Do not forget # to include the primary and foreign keys, otherwise it will raise an error. # [:as] # Specifies a polymorphic interface (See <tt>belongs_to</tt>). # [:through] - # Specifies a join model through which to perform the query. Options for <tt>:class_name</tt> - # and <tt>:foreign_key</tt> are ignored, as the association uses the source reflection. You - # can only use a <tt>:through</tt> query through a <tt>belongs_to</tt>, <tt>has_one</tt> - # or <tt>has_many</tt> association on the join model. The collection of join models - # can be managed via the collection API. For example, new join models are created for - # newly associated objects, and if some are gone their rows are deleted (directly, - # no destroy callbacks are triggered). + # Specifies an association through which to perform the query. This can be any other type + # of association, including other <tt>:through</tt> associations. Options for <tt>:class_name</tt>, + # <tt>:primary_key</tt> and <tt>:foreign_key</tt> are ignored, as the association uses the + # source reflection. + # + # If the association on the join model is a +belongs_to+, the collection can be modified + # and the records on the <tt>:through</tt> model will be automatically created and removed + # as appropriate. Otherwise, the collection is read-only, so you should manipulate the + # <tt>:through</tt> association directly. + # + # If you are going to modify the association (rather than just read from it), then it is + # a good idea to set the <tt>:inverse_of</tt> option on the source association on the + # join model. This allows associated records to be built which will automatically create + # the appropriate join model records when they are saved. (See the 'Association Join Models' + # section above.) # [:source] - # Specifies the source association name used by <tt>has_many :through</tt> queries. - # Only use it if the name cannot be inferred from the association. + # Specifies the source association name used by <tt>has_many :through</tt> queries. + # Only use it if the name cannot be inferred from the association. # <tt>has_many :subscribers, :through => :subscriptions</tt> will look for either <tt>:subscribers</tt> or # <tt>:subscriber</tt> on Subscription, unless a <tt>:source</tt> is given. # [:source_type] @@ -953,15 +1140,14 @@ module ActiveRecord # [:readonly] # If true, all the associated objects are readonly through the association. # [:validate] - # If false, don't validate the associated objects when saving the parent object. true by default. + # If +false+, don't validate the associated objects when saving the parent object. true by default. # [:autosave] - # 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. + # 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. # [:inverse_of] - # Specifies the name of the <tt>belongs_to</tt> association on the associated object - # that is the inverse of this <tt>has_many</tt> association. Does not work in combination + # Specifies the name of the <tt>belongs_to</tt> association on the associated object + # that is the inverse of this <tt>has_many</tt> association. Does not work in combination # with <tt>:through</tt> or <tt>:as</tt> options. # See ActiveRecord::Associations::ClassMethods's overview on Bi-directional associations for more detail. # @@ -979,16 +1165,8 @@ module ActiveRecord # 'FROM people p, post_subscriptions ps ' + # 'WHERE ps.post_id = #{id} AND ps.person_id = p.id ' + # 'ORDER BY p.first_name' - def has_many(association_id, options = {}, &extension) - reflection = create_has_many_reflection(association_id, options, &extension) - configure_dependency_for_has_many(reflection) - add_association_callbacks(reflection.name, reflection.options) - - if options[:through] - collection_accessor_methods(reflection, HasManyThroughAssociation) - else - collection_accessor_methods(reflection, HasManyAssociation) - end + def has_many(name, options = {}, &extension) + Builder::HasMany.build(self, name, options, &extension) end # Specifies a one-to-one association with another class. This method should only be used @@ -1006,12 +1184,14 @@ module ActiveRecord # [build_association(attributes = {})] # Returns a new object of the associated type that has been instantiated # with +attributes+ and linked to this object through a foreign key, but has not - # yet been saved. <b>Note:</b> This ONLY works if an association already exists. - # It will NOT work if the association is +nil+. + # yet been saved. # [create_association(attributes = {})] # Returns a new object of the associated type that has been instantiated # with +attributes+, linked to this object through a foreign key, and that # has already been saved (if it passed the validation). + # [create_association!(attributes = {})] + # Does the same as <tt>create_association</tt>, but raises <tt>ActiveRecord::RecordInvalid</tt> + # if the record is invalid. # # (+association+ is replaced with the symbol passed as the first argument, so # <tt>has_one :manager</tt> would add among others <tt>manager.nil?</tt>.) @@ -1023,6 +1203,7 @@ module ActiveRecord # * <tt>Account#beneficiary=(beneficiary)</tt> (similar to <tt>beneficiary.account_id = account.id; beneficiary.save</tt>) # * <tt>Account#build_beneficiary</tt> (similar to <tt>Beneficiary.new("account_id" => id)</tt>) # * <tt>Account#create_beneficiary</tt> (similar to <tt>b = Beneficiary.new("account_id" => id); b.save; b</tt>) + # * <tt>Account#create_beneficiary!</tt> (similar to <tt>b = Beneficiary.new("account_id" => id); b.save!; b</tt>) # # === Options # @@ -1036,19 +1217,19 @@ module ActiveRecord # [:conditions] # Specify the conditions that the associated object must meet in order to be included as a +WHERE+ # SQL fragment, such as <tt>rank = 5</tt>. Record creation from the association is scoped if a hash - # is used. <tt>has_one :account, :conditions => {:enabled => true}</tt> will create + # is used. <tt>has_one :account, :conditions => {:enabled => true}</tt> will create # an enabled account with <tt>@company.create_account</tt> or <tt>@company.build_account</tt>. # [:order] # Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment, # such as <tt>last_name, first_name DESC</tt>. # [:dependent] # If set to <tt>:destroy</tt>, the associated object is destroyed when this object is. If set to - # <tt>:delete</tt>, the associated object is deleted *without* calling its destroy method. - # If set to <tt>:nullify</tt>, the associated object's foreign key is set to +NULL+. + # <tt>:delete</tt>, the associated object is deleted *without* calling its destroy method. + # If set to <tt>:nullify</tt>, the associated object's foreign key is set to +NULL+. # Also, association is assigned. # [:foreign_key] # Specify the foreign key used for the association. By default this is guessed to be the name - # of this class in lower-case and "_id" suffixed. So a Person class that makes a +has_one+ association + # of this class in lower-case and "_id" suffixed. So a Person class that makes a +has_one+ association # will use "person_id" as the default <tt>:foreign_key</tt>. # [:primary_key] # Specify the method that returns the primary key used for the association. By default this is +id+. @@ -1057,17 +1238,17 @@ module ActiveRecord # [:as] # Specifies a polymorphic interface (See <tt>belongs_to</tt>). # [:select] - # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, - # you want to do a join but not include the joined columns. Do not forget to include the + # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, + # you want to do a join but not include the joined columns. Do not forget to include the # primary and foreign keys, otherwise it will raise an error. # [:through] - # Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt> - # and <tt>:foreign_key</tt> are ignored, as the association uses the source reflection. You - # can only use a <tt>:through</tt> query through a <tt>has_one</tt> or <tt>belongs_to</tt> - # association on the join model. + # Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt>, + # <tt>:primary_key</tt>, and <tt>:foreign_key</tt> are ignored, as the association uses the + # source reflection. You can only use a <tt>:through</tt> query through a <tt>has_one</tt> + # or <tt>belongs_to</tt> association on the join model. # [:source] - # Specifies the source association name used by <tt>has_one :through</tt> queries. - # Only use it if the name cannot be inferred from the association. + # Specifies the source association name used by <tt>has_one :through</tt> queries. + # Only use it if the name cannot be inferred from the association. # <tt>has_one :favorite, :through => :favorites</tt> will look for a # <tt>:favorite</tt> on Favorite, unless a <tt>:source</tt> is given. # [:source_type] @@ -1076,20 +1257,20 @@ module ActiveRecord # [:readonly] # If true, the associated object is readonly through the association. # [:validate] - # If false, don't validate the associated object when saving the parent object. +false+ by default. + # If +false+, don't validate the associated object when saving the parent object. +false+ by default. # [:autosave] - # If true, always save the associated object or destroy it if marked for destruction, + # If true, always save the associated object or destroy it if marked for destruction, # when saving the parent object. If false, never save or destroy the associated object. # By default, only save the associated object if it's a new record. # [:inverse_of] - # Specifies the name of the <tt>belongs_to</tt> association on the associated object - # that is the inverse of this <tt>has_one</tt> association. Does not work in combination + # Specifies the name of the <tt>belongs_to</tt> association on the associated object + # that is the inverse of this <tt>has_one</tt> association. Does not work in combination # with <tt>:through</tt> or <tt>:as</tt> options. # See ActiveRecord::Associations::ClassMethods's overview on Bi-directional associations for more detail. # # Option examples: # has_one :credit_card, :dependent => :destroy # destroys the associated credit card - # has_one :credit_card, :dependent => :nullify # updates the associated records foreign + # has_one :credit_card, :dependent => :nullify # updates the associated records foreign # # key value to NULL rather than destroying it # has_one :last_comment, :class_name => "Comment", :order => "posted_on" # has_one :project_manager, :class_name => "Person", :conditions => "role = 'project_manager'" @@ -1097,17 +1278,8 @@ module ActiveRecord # has_one :boss, :readonly => :true # has_one :club, :through => :membership # has_one :primary_address, :through => :addressables, :conditions => ["addressable.primary = ?", true], :source => :addressable - def has_one(association_id, options = {}) - if options[:through] - reflection = create_has_one_through_reflection(association_id, options) - association_accessor_methods(reflection, ActiveRecord::Associations::HasOneThroughAssociation) - else - reflection = create_has_one_reflection(association_id, options) - association_accessor_methods(reflection, HasOneAssociation) - association_constructor_method(:build, reflection, HasOneAssociation) - association_constructor_method(:create, reflection, HasOneAssociation) - configure_dependency_for_has_one(reflection) - end + def has_one(name, options = {}) + Builder::HasOne.build(self, name, options) end # Specifies a one-to-one association with another class. This method should only be used @@ -1129,6 +1301,9 @@ module ActiveRecord # Returns a new object of the associated type that has been instantiated # with +attributes+, linked to this object through a foreign key, and that # has already been saved (if it passed the validation). + # [create_association!(attributes = {})] + # Does the same as <tt>create_association</tt>, but raises <tt>ActiveRecord::RecordInvalid</tt> + # if the record is invalid. # # (+association+ is replaced with the symbol passed as the first argument, so # <tt>belongs_to :author</tt> would add among others <tt>author.nil?</tt>.) @@ -1140,6 +1315,7 @@ module ActiveRecord # * <tt>Post#author=(author)</tt> (similar to <tt>post.author_id = author.id</tt>) # * <tt>Post#build_author</tt> (similar to <tt>post.author = Author.new</tt>) # * <tt>Post#create_author</tt> (similar to <tt>post.author = Author.new; post.author.save; post.author</tt>) + # * <tt>Post#create_author!</tt> (similar to <tt>post.author = Author.new; post.author.save!; post.author</tt>) # The declaration can also include an options hash to specialize the behavior of the association. # # === Options @@ -1152,33 +1328,38 @@ module ActiveRecord # Specify the conditions that the associated object must meet in order to be included as a +WHERE+ # SQL fragment, such as <tt>authorized = 1</tt>. # [:select] - # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed - # if, for example, you want to do a join but not include the joined columns. Do not + # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed + # if, for example, you want to do a join but not include the joined columns. Do not # forget to include the primary and foreign keys, otherwise it will raise an error. # [:foreign_key] # Specify the foreign key used for the association. By default this is guessed to be the name - # of the association with an "_id" suffix. So a class that defines a <tt>belongs_to :person</tt> - # association will use "person_id" as the default <tt>:foreign_key</tt>. Similarly, - # <tt>belongs_to :favorite_person, :class_name => "Person"</tt> will use a foreign key + # of the association with an "_id" suffix. So a class that defines a <tt>belongs_to :person</tt> + # association will use "person_id" as the default <tt>:foreign_key</tt>. Similarly, + # <tt>belongs_to :favorite_person, :class_name => "Person"</tt> will use a foreign key # of "favorite_person_id". + # [:foreign_type] + # Specify the column used to store the associated object's type, if this is a polymorphic + # association. By default this is guessed to be the name of the association with a "_type" + # suffix. So a class that defines a <tt>belongs_to :taggable, :polymorphic => true</tt> + # association will use "taggable_type" as the default <tt>:foreign_type</tt>. # [:primary_key] - # Specify the method that returns the primary key of associated object used for the association. + # Specify the method that returns the primary key of associated object used for the association. # By default this is id. # [:dependent] # If set to <tt>:destroy</tt>, the associated object is destroyed when this object is. If set to - # <tt>:delete</tt>, the associated object is deleted *without* calling its destroy method. - # This option should not be specified when <tt>belongs_to</tt> is used in conjunction with + # <tt>:delete</tt>, the associated object is deleted *without* calling its destroy method. + # This option should not be specified when <tt>belongs_to</tt> is used in conjunction with # a <tt>has_many</tt> relationship on another class because of the potential to leave # orphaned records behind. # [:counter_cache] # Caches the number of belonging objects on the associate class through the use of +increment_counter+ - # and +decrement_counter+. The counter cache is incremented when an object of this - # class is created and decremented when it's destroyed. This requires that a column + # and +decrement_counter+. The counter cache is incremented when an object of this + # 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). You can also specify a custom counter - # cache column by providing a column name instead of a +true+/+false+ value to this + # is used on the associate class (such as a Post class). 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>.) - # Note: Specifying a counter cache will add it to that model's list of readonly attributes + # Note: Specifying a counter cache will add it to that model's list of readonly attributes # using +attr_readonly+. # [:include] # Specify second-order associations that should be eager loaded when this object is loaded. @@ -1189,19 +1370,19 @@ module ActiveRecord # [:readonly] # If true, the associated object is readonly through the association. # [:validate] - # If false, don't validate the associated objects when saving the parent object. +false+ by default. + # If +false+, don't validate the associated objects when saving the parent object. +false+ by default. # [:autosave] - # If true, always save the associated object or destroy it if marked for destruction, when + # If true, always save the associated object or destroy it if marked for destruction, when # saving the parent object. # If false, never save or destroy the associated object. # By default, only save the associated object if it's a new record. # [:touch] - # If true, the associated object will be touched (the updated_at/on attributes set to now) - # when this record is either saved or destroyed. If you specify a symbol, that attribute + # If true, the associated object will be touched (the updated_at/on attributes set to now) + # when this record is either saved or destroyed. If you specify a symbol, that attribute # will be updated with the current time instead of the updated_at/on attribute. # [:inverse_of] - # Specifies the name of the <tt>has_one</tt> or <tt>has_many</tt> association on the associated - # object that is the inverse of this <tt>belongs_to</tt> association. Does not work in + # Specifies the name of the <tt>has_one</tt> or <tt>has_many</tt> association on the associated + # object that is the inverse of this <tt>belongs_to</tt> association. Does not work in # combination with the <tt>:polymorphic</tt> options. # See ActiveRecord::Associations::ClassMethods's overview on Bi-directional associations for more detail. # @@ -1216,29 +1397,16 @@ module ActiveRecord # belongs_to :post, :counter_cache => true # belongs_to :company, :touch => true # belongs_to :company, :touch => :employees_last_updated_at - def belongs_to(association_id, options = {}) - reflection = create_belongs_to_reflection(association_id, options) - - if reflection.options[:polymorphic] - association_accessor_methods(reflection, BelongsToPolymorphicAssociation) - else - association_accessor_methods(reflection, BelongsToAssociation) - association_constructor_method(:build, reflection, BelongsToAssociation) - association_constructor_method(:create, reflection, BelongsToAssociation) - end - - add_counter_cache_callbacks(reflection) if options[:counter_cache] - add_touch_callbacks(reflection, options[:touch]) if options[:touch] - - configure_dependency_for_belongs_to(reflection) + def belongs_to(name, options = {}) + Builder::BelongsTo.build(self, name, options) end # Specifies a many-to-many relationship with another class. This associates two classes via an # intermediate join table. Unless the join table is explicitly specified as an option, it is # guessed using the lexical order of the class names. So a join between Developer and Project - # will give the default join table name of "developers_projects" because "D" outranks "P". - # Note that this precedence is calculated using the <tt><</tt> operator for String. This - # means that if the strings are of different lengths, and the strings are equal when compared + # will give the default join table name of "developers_projects" because "D" outranks "P". + # Note that this precedence is calculated using the <tt><</tt> operator for String. This + # means that if the strings are of different lengths, and the strings are equal when compared # up to the shortest length, then the longer string is considered of higher # lexical precedence than the shorter one. For example, one would expect the tables "paper_boxes" and "papers" # to generate a join table name of "papers_paper_boxes" because of the length of the name "paper_boxes", @@ -1261,12 +1429,6 @@ module ActiveRecord # end # end # - # Deprecated: Any additional fields added to the join table will be placed as attributes when - # pulling records out through +has_and_belongs_to_many+ associations. Records returned from join - # tables with additional attributes will be marked as readonly (because we can't save changes - # to the additional attributes). It's strongly recommended that you upgrade any - # associations with attributes to a real join model (see introduction). - # # Adds the following methods for retrieval and query: # # [collection(force_reload = false)] @@ -1275,7 +1437,7 @@ 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. # [collection.delete(object, ...)] # Removes one or more objects from the collection by removing their associations from the join table. @@ -1304,7 +1466,7 @@ module ActiveRecord # with +attributes+ and linked to this object through the join table, but has not yet been saved. # [collection.create(attributes = {})] # Returns a new object of the collection type that has been instantiated - # with +attributes+, linked to this object through the join table, and that has already been + # with +attributes+, linked to this object through the join table, and that has already been # saved (if it passed the validation). # # (+collection+ is replaced with the symbol passed as the first argument, so @@ -1340,8 +1502,8 @@ module ActiveRecord # MUST be declared underneath any +has_and_belongs_to_many+ declaration in order to work. # [:foreign_key] # Specify the foreign key used for the association. By default this is guessed to be the name - # of this class in lower-case and "_id" suffixed. So a Person class that makes - # a +has_and_belongs_to_many+ association to Project will use "person_id" as the + # of this class in lower-case and "_id" suffixed. So a Person class that makes + # a +has_and_belongs_to_many+ association to Project will use "person_id" as the # default <tt>:foreign_key</tt>. # [:association_foreign_key] # Specify the foreign key used for the association on the receiving side of the association. @@ -1350,7 +1512,7 @@ module ActiveRecord # the association will use "project_id" as the default <tt>:association_foreign_key</tt>. # [:conditions] # Specify the conditions that the associated object must meet in order to be included as a +WHERE+ - # SQL fragment, such as <tt>authorized = 1</tt>. Record creations from the association are + # SQL fragment, such as <tt>authorized = 1</tt>. Record creations from the association are # scoped if a hash is used. # <tt>has_many :posts, :conditions => {:published => true}</tt> will create published posts with <tt>@blog.posts.create</tt> # or <tt>@blog.posts.build</tt>. @@ -1363,7 +1525,7 @@ module ActiveRecord # Overwrite the default generated SQL statement used to fetch the association with a manual statement # [:counter_sql] # Specify a complete SQL statement to fetch the size of the association. If <tt>:finder_sql</tt> is - # specified but not <tt>:counter_sql</tt>, <tt>:counter_sql</tt> will be generated by + # specified but not <tt>:counter_sql</tt>, <tt>:counter_sql</tt> will be generated by # replacing <tt>SELECT ... FROM</tt> with <tt>SELECT COUNT(*) FROM</tt>. # [:delete_sql] # Overwrite the default generated SQL statement used to remove links between the associated @@ -1378,23 +1540,23 @@ module ActiveRecord # [:group] # An attribute name by which the result should be grouped. Uses the <tt>GROUP BY</tt> SQL-clause. # [:having] - # Combined with +:group+ this can be used to filter the records that a <tt>GROUP BY</tt> returns. + # Combined with +:group+ this can be used to filter the records that a <tt>GROUP BY</tt> returns. # Uses the <tt>HAVING</tt> SQL-clause. # [:limit] # An integer determining the limit on the number of rows that should be returned. # [:offset] - # An integer determining the offset from where the rows should be fetched. So at 5, + # An integer determining the offset from where the rows should be fetched. So at 5, # it would skip the first 4 rows. # [:select] - # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, - # you want to do a join but not include the joined columns. Do not forget to include the primary + # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, + # you want to do a join but not include the joined columns. Do not forget to include the primary # and foreign keys, otherwise it will raise an error. # [:readonly] # If true, all the associated objects are readonly through the association. # [:validate] - # If false, don't validate the associated objects when saving the parent object. +true+ by default. + # If +false+, don't validate the associated objects when saving the parent object. +true+ by default. # [:autosave] - # If true, always save the associated objects or destroy them if marked for destruction, when + # 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. @@ -1407,845 +1569,9 @@ module ActiveRecord # has_and_belongs_to_many :categories, :readonly => true # has_and_belongs_to_many :active_projects, :join_table => 'developers_projects', :delete_sql => # 'DELETE FROM developers_projects WHERE active=1 AND developer_id = #{id} AND project_id = #{record.id}' - def has_and_belongs_to_many(association_id, options = {}, &extension) - reflection = create_has_and_belongs_to_many_reflection(association_id, options, &extension) - collection_accessor_methods(reflection, HasAndBelongsToManyAssociation) - - # Don't use a before_destroy callback since users' before_destroy - # callbacks will be executed after the association is wiped out. - include Module.new { - class_eval <<-RUBY, __FILE__, __LINE__ + 1 - def destroy # def destroy - super # super - #{reflection.name}.clear # posts.clear - end # end - RUBY - } - - add_association_callbacks(reflection.name, options) + def has_and_belongs_to_many(name, options = {}, &extension) + Builder::HasAndBelongsToMany.build(self, name, options, &extension) end - - private - # Generates a join table name from two provided table names. - # The names in the join table names end up in lexicographic order. - # - # join_table_name("members", "clubs") # => "clubs_members" - # join_table_name("members", "special_clubs") # => "members_special_clubs" - def join_table_name(first_table_name, second_table_name) - if first_table_name < second_table_name - join_table = "#{first_table_name}_#{second_table_name}" - else - join_table = "#{second_table_name}_#{first_table_name}" - end - - table_name_prefix + join_table + table_name_suffix - end - - def association_accessor_methods(reflection, association_proxy_class) - redefine_method(reflection.name) do |*params| - force_reload = params.first unless params.empty? - association = association_instance_get(reflection.name) - - if association.nil? || force_reload - association = association_proxy_class.new(self, reflection) - retval = force_reload ? reflection.klass.uncached { association.reload } : association.reload - if retval.nil? and association_proxy_class == BelongsToAssociation - association_instance_set(reflection.name, nil) - return nil - end - association_instance_set(reflection.name, association) - end - - association.target.nil? ? nil : association - end - - redefine_method("loaded_#{reflection.name}?") do - association = association_instance_get(reflection.name) - association && association.loaded? - end - - redefine_method("#{reflection.name}=") do |new_value| - association = association_instance_get(reflection.name) - - if association.nil? || association.target != new_value - association = association_proxy_class.new(self, reflection) - end - - association.replace(new_value) - association_instance_set(reflection.name, new_value.nil? ? nil : association) - end - - redefine_method("set_#{reflection.name}_target") do |target| - return if target.nil? and association_proxy_class == BelongsToAssociation - association = association_proxy_class.new(self, reflection) - association.target = target - association_instance_set(reflection.name, association) - end - end - - def collection_reader_method(reflection, association_proxy_class) - redefine_method(reflection.name) do |*params| - force_reload = params.first unless params.empty? - association = association_instance_get(reflection.name) - - unless association - association = association_proxy_class.new(self, reflection) - association_instance_set(reflection.name, association) - end - - reflection.klass.uncached { association.reload } if force_reload - - association - end - - redefine_method("#{reflection.name.to_s.singularize}_ids") do - if send(reflection.name).loaded? || reflection.options[:finder_sql] - send(reflection.name).map(&:id) - else - if reflection.through_reflection && reflection.source_reflection.belongs_to? - through = reflection.through_reflection - primary_key = reflection.source_reflection.primary_key_name - send(through.name).select("DISTINCT #{through.quoted_table_name}.#{primary_key}").map!(&:"#{primary_key}") - else - send(reflection.name).select("#{reflection.quoted_table_name}.#{reflection.klass.primary_key}").except(:includes).map!(&:id) - end - end - end - - end - - def collection_accessor_methods(reflection, association_proxy_class, writer = true) - collection_reader_method(reflection, association_proxy_class) - - if writer - redefine_method("#{reflection.name}=") do |new_value| - # Loads proxy class instance (defined in collection_reader_method) if not already loaded - association = send(reflection.name) - association.replace(new_value) - association - end - - redefine_method("#{reflection.name.to_s.singularize}_ids=") do |new_value| - pk_column = reflection.primary_key_column - ids = (new_value || []).reject { |nid| nid.blank? } - ids.map!{ |i| pk_column.type_cast(i) } - send("#{reflection.name}=", reflection.klass.find(ids).index_by(&:id).values_at(*ids)) - end - end - end - - def association_constructor_method(constructor, reflection, association_proxy_class) - redefine_method("#{constructor}_#{reflection.name}") do |*params| - attributees = params.first unless params.empty? - replace_existing = params[1].nil? ? true : params[1] - association = association_instance_get(reflection.name) - - unless association - association = association_proxy_class.new(self, reflection) - association_instance_set(reflection.name, association) - end - - if association_proxy_class == HasOneAssociation - association.send(constructor, attributees, replace_existing) - else - association.send(constructor, attributees) - end - end - end - - def add_counter_cache_callbacks(reflection) - cache_column = reflection.counter_cache_column - - method_name = "belongs_to_counter_cache_after_create_for_#{reflection.name}".to_sym - define_method(method_name) do - association = send(reflection.name) - association.class.increment_counter(cache_column, association.id) unless association.nil? - end - after_create(method_name) - - method_name = "belongs_to_counter_cache_before_destroy_for_#{reflection.name}".to_sym - define_method(method_name) do - association = send(reflection.name) - association.class.decrement_counter(cache_column, association.id) unless association.nil? - end - before_destroy(method_name) - - module_eval( - "#{reflection.class_name}.send(:attr_readonly,\"#{cache_column}\".intern) if defined?(#{reflection.class_name}) && #{reflection.class_name}.respond_to?(:attr_readonly)", __FILE__, __LINE__ - ) - end - - def add_touch_callbacks(reflection, touch_attribute) - method_name = :"belongs_to_touch_after_save_or_destroy_for_#{reflection.name}" - redefine_method(method_name) do - association = send(reflection.name) - - if touch_attribute == true - association.touch unless association.nil? - else - association.touch(touch_attribute) unless association.nil? - end - end - after_save(method_name) - after_touch(method_name) - after_destroy(method_name) - end - - # Creates before_destroy callback methods that nullify, delete or destroy - # has_many associated objects, according to the defined :dependent rule. - # - # See HasManyAssociation#delete_records for more information. In general - # - delete children if the option is set to :destroy or :delete_all - # - set the foreign key to NULL if the option is set to :nullify - # - do not delete the parent record if there is any child record if the - # option is set to :restrict - # - # The +extra_conditions+ parameter, which is not used within the main - # Active Record codebase, is meant to allow plugins to define extra - # finder conditions. - def configure_dependency_for_has_many(reflection, extra_conditions = nil) - if reflection.options.include?(:dependent) - case reflection.options[:dependent] - when :destroy - method_name = "has_many_dependent_destroy_for_#{reflection.name}".to_sym - define_method(method_name) do - send(reflection.name).each do |o| - # No point in executing the counter update since we're going to destroy the parent anyway - counter_method = ('belongs_to_counter_cache_before_destroy_for_' + self.class.name.downcase).to_sym - if(o.respond_to? counter_method) then - class << o - self - end.send(:define_method, counter_method, Proc.new {}) - end - o.destroy - end - end - before_destroy method_name - when :delete_all - before_destroy do |record| - self.class.send(:delete_all_has_many_dependencies, - record, - reflection.name, - reflection.klass, - reflection.dependent_conditions(record, self.class, extra_conditions)) - end - when :nullify - before_destroy do |record| - self.class.send(:nullify_has_many_dependencies, - record, - reflection.name, - reflection.klass, - reflection.primary_key_name, - reflection.dependent_conditions(record, self.class, extra_conditions)) - end - when :restrict - method_name = "has_many_dependent_restrict_for_#{reflection.name}".to_sym - define_method(method_name) do - unless send(reflection.name).empty? - raise DeleteRestrictionError.new(reflection) - end - end - before_destroy method_name - else - raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, :nullify or :restrict (#{reflection.options[:dependent].inspect})" - end - end - end - - # Creates before_destroy callback methods that nullify, delete or destroy - # has_one associated objects, according to the defined :dependent rule. - # If the association is marked as :dependent => :restrict, create a callback - # that prevents deleting entirely. - def configure_dependency_for_has_one(reflection) - if reflection.options.include?(:dependent) - name = reflection.options[:dependent] - method_name = :"has_one_dependent_#{name}_for_#{reflection.name}" - - case name - when :destroy, :delete - class_eval <<-eoruby, __FILE__, __LINE__ + 1 - def #{method_name} - association = #{reflection.name} - association.#{name} if association - end - eoruby - when :nullify - class_eval <<-eoruby, __FILE__, __LINE__ + 1 - def #{method_name} - association = #{reflection.name} - association.update_attribute(#{reflection.primary_key_name.inspect}, nil) if association - end - eoruby - when :restrict - method_name = "has_one_dependent_restrict_for_#{reflection.name}".to_sym - define_method(method_name) do - unless send(reflection.name).nil? - raise DeleteRestrictionError.new(reflection) - end - end - before_destroy method_name - else - raise ArgumentError, "The :dependent option expects either :destroy, :delete, :nullify or :restrict (#{reflection.options[:dependent].inspect})" - end - - before_destroy method_name - end - end - - def configure_dependency_for_belongs_to(reflection) - if reflection.options.include?(:dependent) - name = reflection.options[:dependent] - - unless [:destroy, :delete].include?(name) - raise ArgumentError, "The :dependent option expects either :destroy or :delete (#{reflection.options[:dependent].inspect})" - end - - method_name = :"belongs_to_dependent_#{name}_for_#{reflection.name}" - class_eval <<-eoruby, __FILE__, __LINE__ + 1 - def #{method_name} - association = #{reflection.name} - association.#{name} if association - end - eoruby - after_destroy method_name - end - end - - def delete_all_has_many_dependencies(record, reflection_name, association_class, dependent_conditions) - association_class.delete_all(dependent_conditions) - end - - def nullify_has_many_dependencies(record, reflection_name, association_class, primary_key_name, dependent_conditions) - association_class.update_all("#{primary_key_name} = NULL", dependent_conditions) - end - - mattr_accessor :valid_keys_for_has_many_association - @@valid_keys_for_has_many_association = [ - :class_name, :table_name, :foreign_key, :primary_key, - :dependent, - :select, :conditions, :include, :order, :group, :having, :limit, :offset, - :as, :through, :source, :source_type, - :uniq, - :finder_sql, :counter_sql, - :before_add, :after_add, :before_remove, :after_remove, - :extend, :readonly, - :validate, :inverse_of - ] - - def create_has_many_reflection(association_id, options, &extension) - options.assert_valid_keys(valid_keys_for_has_many_association) - options[:extend] = create_extension_modules(association_id, extension, options[:extend]) - - create_reflection(:has_many, association_id, options, self) - end - - mattr_accessor :valid_keys_for_has_one_association - @@valid_keys_for_has_one_association = [ - :class_name, :foreign_key, :remote, :select, :conditions, :order, - :include, :dependent, :counter_cache, :extend, :as, :readonly, - :validate, :primary_key, :inverse_of - ] - - def create_has_one_reflection(association_id, options) - options.assert_valid_keys(valid_keys_for_has_one_association) - create_reflection(:has_one, association_id, options, self) - end - - def create_has_one_through_reflection(association_id, options) - options.assert_valid_keys( - :class_name, :foreign_key, :remote, :select, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :through, :source, :source_type, :validate - ) - create_reflection(:has_one, association_id, options, self) - end - - mattr_accessor :valid_keys_for_belongs_to_association - @@valid_keys_for_belongs_to_association = [ - :class_name, :primary_key, :foreign_key, :foreign_type, :remote, :select, :conditions, - :include, :dependent, :counter_cache, :extend, :polymorphic, :readonly, - :validate, :touch, :inverse_of - ] - - def create_belongs_to_reflection(association_id, options) - options.assert_valid_keys(valid_keys_for_belongs_to_association) - reflection = create_reflection(:belongs_to, association_id, options, self) - - if options[:polymorphic] - reflection.options[:foreign_type] ||= reflection.class_name.underscore + "_type" - end - - reflection - end - - mattr_accessor :valid_keys_for_has_and_belongs_to_many_association - @@valid_keys_for_has_and_belongs_to_many_association = [ - :class_name, :table_name, :join_table, :foreign_key, :association_foreign_key, - :select, :conditions, :include, :order, :group, :having, :limit, :offset, - :uniq, - :finder_sql, :counter_sql, :delete_sql, :insert_sql, - :before_add, :after_add, :before_remove, :after_remove, - :extend, :readonly, - :validate - ] - - def create_has_and_belongs_to_many_reflection(association_id, options, &extension) - options.assert_valid_keys(valid_keys_for_has_and_belongs_to_many_association) - options[:extend] = create_extension_modules(association_id, extension, options[:extend]) - - reflection = create_reflection(:has_and_belongs_to_many, association_id, options, self) - - if reflection.association_foreign_key == reflection.primary_key_name - raise HasAndBelongsToManyAssociationForeignKeyNeeded.new(reflection) - end - - reflection.options[:join_table] ||= join_table_name(undecorated_table_name(self.to_s), undecorated_table_name(reflection.class_name)) - if connection.supports_primary_key? && (connection.primary_key(reflection.options[:join_table]) rescue false) - raise HasAndBelongsToManyAssociationWithPrimaryKeyError.new(reflection) - end - - reflection - end - - def add_association_callbacks(association_name, options) - callbacks = %w(before_add after_add before_remove after_remove) - callbacks.each do |callback_name| - full_callback_name = "#{callback_name}_for_#{association_name}" - defined_callbacks = options[callback_name.to_sym] - if options.has_key?(callback_name.to_sym) - class_inheritable_reader full_callback_name.to_sym - write_inheritable_attribute(full_callback_name.to_sym, [defined_callbacks].flatten) - else - write_inheritable_attribute(full_callback_name.to_sym, []) - end - end - end - - def create_extension_modules(association_id, block_extension, extensions) - if block_extension - extension_module_name = "#{self.to_s.demodulize}#{association_id.to_s.camelize}AssociationExtension" - - silence_warnings do - self.parent.const_set(extension_module_name, Module.new(&block_extension)) - end - Array.wrap(extensions).push("#{self.parent}::#{extension_module_name}".constantize) - else - Array.wrap(extensions) - end - end - - class JoinDependency # :nodoc: - attr_reader :joins, :reflections, :table_aliases - - def initialize(base, associations, joins) - @joins = [JoinBase.new(base, joins)] - @associations = associations - @reflections = [] - @base_records_hash = {} - @base_records_in_order = [] - @table_aliases = Hash.new { |aliases, table| aliases[table] = 0 } - @table_aliases[base.table_name] = 1 - build(associations) - end - - def graft(*associations) - associations.each do |association| - join_associations.detect {|a| association == a} || - build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_class) - end - self - end - - def join_associations - @joins[1..-1].to_a - end - - def join_base - @joins[0] - end - - def count_aliases_from_table_joins(name) - # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase - quoted_name = join_base.active_record.connection.quote_table_name(name.downcase).downcase - join_sql = join_base.table_joins.to_s.downcase - join_sql.blank? ? 0 : - # Table names - join_sql.scan(/join(?:\s+\w+)?\s+#{quoted_name}\son/).size + - # Table aliases - join_sql.scan(/join(?:\s+\w+)?\s+\S+\s+#{quoted_name}\son/).size - end - - def instantiate(rows) - rows.each_with_index do |row, i| - primary_id = join_base.record_id(row) - unless @base_records_hash[primary_id] - @base_records_in_order << (@base_records_hash[primary_id] = join_base.instantiate(row)) - end - construct(@base_records_hash[primary_id], @associations, join_associations.dup, row) - end - remove_duplicate_results!(join_base.active_record, @base_records_in_order, @associations) - return @base_records_in_order - end - - def remove_duplicate_results!(base, records, associations) - case associations - when Symbol, String - reflection = base.reflections[associations] - remove_uniq_by_reflection(reflection, records) - when Array - associations.each do |association| - remove_duplicate_results!(base, records, association) - end - when Hash - associations.keys.each do |name| - reflection = base.reflections[name] - remove_uniq_by_reflection(reflection, records) - - parent_records = [] - records.each do |record| - if descendant = record.send(reflection.name) - if reflection.collection? - parent_records.concat descendant.target.uniq - else - parent_records << descendant - end - end - end - - remove_duplicate_results!(reflection.klass, parent_records, associations[name]) unless parent_records.empty? - end - end - end - - protected - - def build(associations, parent = nil, join_class = Arel::InnerJoin) - parent ||= @joins.last - case associations - when Symbol, String - reflection = parent.reflections[associations.to_s.intern] or - raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?" - @reflections << reflection - @joins << build_join_association(reflection, parent).with_join_class(join_class) - when Array - associations.each do |association| - build(association, parent, join_class) - end - when Hash - associations.keys.sort{|a,b|a.to_s<=>b.to_s}.each do |name| - build(name, parent, join_class) - build(associations[name], nil, join_class) - end - else - raise ConfigurationError, associations.inspect - end - end - - def remove_uniq_by_reflection(reflection, records) - if reflection && reflection.collection? - records.each { |record| record.send(reflection.name).target.uniq! } - end - end - - def build_join_association(reflection, parent) - JoinAssociation.new(reflection, self, parent) - end - - def construct(parent, associations, joins, row) - case associations - when Symbol, String - join = joins.detect{|j| j.reflection.name.to_s == associations.to_s && j.parent_table_name == parent.class.table_name } - raise(ConfigurationError, "No such association") if join.nil? - - joins.delete(join) - construct_association(parent, join, row) - when Array - associations.each do |association| - construct(parent, association, joins, row) - end - when Hash - associations.keys.sort{|a,b|a.to_s<=>b.to_s}.each do |name| - join = joins.detect{|j| j.reflection.name.to_s == name.to_s && j.parent_table_name == parent.class.table_name } - raise(ConfigurationError, "No such association") if join.nil? - - association = construct_association(parent, join, row) - joins.delete(join) - construct(association, associations[name], joins, row) if association - end - else - raise ConfigurationError, associations.inspect - end - end - - def construct_association(record, join, row) - case join.reflection.macro - when :has_many, :has_and_belongs_to_many - collection = record.send(join.reflection.name) - collection.loaded - - return nil if record.id.to_s != join.parent.record_id(row).to_s or row[join.aliased_primary_key].nil? - association = join.instantiate(row) - collection.target.push(association) - collection.__send__(:set_inverse_instance, association, record) - when :has_one - return if record.id.to_s != join.parent.record_id(row).to_s - return if record.instance_variable_defined?("@#{join.reflection.name}") - association = join.instantiate(row) unless row[join.aliased_primary_key].nil? - set_target_and_inverse(join, association, record) - when :belongs_to - return if record.id.to_s != join.parent.record_id(row).to_s or row[join.aliased_primary_key].nil? - association = join.instantiate(row) - set_target_and_inverse(join, association, record) - else - raise ConfigurationError, "unknown macro: #{join.reflection.macro}" - end - return association - end - - def set_target_and_inverse(join, association, record) - association_proxy = record.send("set_#{join.reflection.name}_target", association) - association_proxy.__send__(:set_inverse_instance, association, record) - end - - class JoinBase # :nodoc: - attr_reader :active_record, :table_joins - delegate :table_name, :column_names, :primary_key, :reflections, :sanitize_sql, :arel_engine, :to => :active_record - - def initialize(active_record, joins = nil) - @active_record = active_record - @cached_record = {} - @table_joins = joins - end - - def ==(other) - other.class == self.class && - other.active_record == active_record && - other.table_joins == table_joins - end - - def aliased_prefix - "t0" - end - - def aliased_primary_key - "#{aliased_prefix}_r0" - end - - def aliased_table_name - active_record.table_name - end - - def column_names_with_alias - unless defined?(@column_names_with_alias) - @column_names_with_alias = [] - - ([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i| - @column_names_with_alias << [column_name, "#{aliased_prefix}_r#{i}"] - end - end - - @column_names_with_alias - end - - def extract_record(row) - column_names_with_alias.inject({}){|record, (cn, an)| record[cn] = row[an]; record} - end - - def record_id(row) - row[aliased_primary_key] - end - - def instantiate(row) - @cached_record[record_id(row)] ||= active_record.send(:instantiate, extract_record(row)) - end - end - - class JoinAssociation < JoinBase # :nodoc: - attr_reader :reflection, :parent, :aliased_table_name, :aliased_prefix, :aliased_join_table_name, :parent_table_name, :join_class - delegate :options, :klass, :through_reflection, :source_reflection, :to => :reflection - - def initialize(reflection, join_dependency, parent = nil) - reflection.check_validity! - if reflection.options[:polymorphic] - raise EagerLoadPolymorphicError.new(reflection) - end - - super(reflection.klass) - @join_dependency = join_dependency - @parent = parent - @reflection = reflection - @aliased_prefix = "t#{ join_dependency.joins.size }" - @parent_table_name = parent.active_record.table_name - @aliased_table_name = aliased_table_name_for(table_name) - @join = nil - @join_class = Arel::InnerJoin - - if reflection.macro == :has_and_belongs_to_many - @aliased_join_table_name = aliased_table_name_for(reflection.options[:join_table], "_join") - end - - if [:has_many, :has_one].include?(reflection.macro) && reflection.options[:through] - @aliased_join_table_name = aliased_table_name_for(reflection.through_reflection.klass.table_name, "_join") - end - end - - def ==(other) - other.class == self.class && - other.reflection == reflection && - other.parent == parent - end - - def find_parent_in(other_join_dependency) - other_join_dependency.joins.detect do |join| - self.parent == join - end - end - - def with_join_class(join_class) - @join_class = join_class - self - end - - def association_join - return @join if @join - - aliased_table = Arel::Table.new(table_name, :as => @aliased_table_name, :engine => arel_engine) - parent_table = Arel::Table.new(parent.table_name, :as => parent.aliased_table_name, :engine => arel_engine) - - @join = case reflection.macro - when :has_and_belongs_to_many - join_table = Arel::Table.new(options[:join_table], :as => aliased_join_table_name, :engine => arel_engine) - fk = options[:foreign_key] || reflection.active_record.to_s.foreign_key - klass_fk = options[:association_foreign_key] || klass.to_s.foreign_key - - [ - join_table[fk].eq(parent_table[reflection.active_record.primary_key]), - aliased_table[klass.primary_key].eq(join_table[klass_fk]) - ] - when :has_many, :has_one - if reflection.options[:through] - join_table = Arel::Table.new(through_reflection.klass.table_name, :as => aliased_join_table_name, :engine => arel_engine) - jt_foreign_key = jt_as_extra = jt_source_extra = jt_sti_extra = nil - first_key = second_key = as_extra = nil - - if through_reflection.options[:as] # has_many :through against a polymorphic join - jt_foreign_key = through_reflection.options[:as].to_s + '_id' - jt_as_extra = join_table[through_reflection.options[:as].to_s + '_type'].eq(parent.active_record.base_class.name) - else - jt_foreign_key = through_reflection.primary_key_name - end - - case source_reflection.macro - when :has_many - if source_reflection.options[:as] - first_key = "#{source_reflection.options[:as]}_id" - second_key = options[:foreign_key] || primary_key - as_extra = aliased_table["#{source_reflection.options[:as]}_type"].eq(source_reflection.active_record.base_class.name) - else - first_key = through_reflection.klass.base_class.to_s.foreign_key - second_key = options[:foreign_key] || primary_key - end - - unless through_reflection.klass.descends_from_active_record? - jt_sti_extra = join_table[through_reflection.active_record.inheritance_column].eq(through_reflection.klass.sti_name) - end - when :belongs_to - first_key = primary_key - if reflection.options[:source_type] - second_key = source_reflection.association_foreign_key - jt_source_extra = join_table[reflection.source_reflection.options[:foreign_type]].eq(reflection.options[:source_type]) - else - second_key = source_reflection.primary_key_name - end - end - - [ - [parent_table[parent.primary_key].eq(join_table[jt_foreign_key]), jt_as_extra, jt_source_extra, jt_sti_extra].reject{|x| x.blank? }, - aliased_table[first_key].eq(join_table[second_key]) - ] - elsif reflection.options[:as] - id_rel = aliased_table["#{reflection.options[:as]}_id"].eq(parent_table[parent.primary_key]) - type_rel = aliased_table["#{reflection.options[:as]}_type"].eq(parent.active_record.base_class.name) - [id_rel, type_rel] - else - foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key - [aliased_table[foreign_key].eq(parent_table[reflection.options[:primary_key] || parent.primary_key])] - end - when :belongs_to - [aliased_table[options[:primary_key] || reflection.klass.primary_key].eq(parent_table[options[:foreign_key] || reflection.primary_key_name])] - end - - unless klass.descends_from_active_record? - sti_column = aliased_table[klass.inheritance_column] - sti_condition = sti_column.eq(klass.sti_name) - klass.descendants.each {|subclass| sti_condition = sti_condition.or(sti_column.eq(subclass.sti_name)) } - - @join << sti_condition - end - - [through_reflection, reflection].each do |ref| - if ref && ref.options[:conditions] - @join << interpolate_sql(sanitize_sql(ref.options[:conditions], aliased_table_name)) - end - end - - @join - end - - def relation - aliased = Arel::Table.new(table_name, :as => @aliased_table_name, :engine => arel_engine) - - if reflection.macro == :has_and_belongs_to_many - [Arel::Table.new(options[:join_table], :as => aliased_join_table_name, :engine => arel_engine), aliased] - elsif reflection.options[:through] - [Arel::Table.new(through_reflection.klass.table_name, :as => aliased_join_table_name, :engine => arel_engine), aliased] - else - aliased - end - end - - def join_relation(joining_relation, join = nil) - joining_relation.joins(self.with_join_class(Arel::OuterJoin)) - end - - protected - - def aliased_table_name_for(name, suffix = nil) - if @join_dependency.table_aliases[name].zero? - @join_dependency.table_aliases[name] = @join_dependency.count_aliases_from_table_joins(name) - end - - if !@join_dependency.table_aliases[name].zero? # We need an alias - name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}" - @join_dependency.table_aliases[name] += 1 - if @join_dependency.table_aliases[name] == 1 # First time we've seen this name - # Also need to count the aliases from the table_aliases to avoid incorrect count - @join_dependency.table_aliases[name] += @join_dependency.count_aliases_from_table_joins(name) - end - table_index = @join_dependency.table_aliases[name] - name = name[0..active_record.connection.table_alias_length-3] + "_#{table_index}" if table_index > 1 - else - @join_dependency.table_aliases[name] += 1 - end - - name - end - - def pluralize(table_name) - ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name - end - - def table_alias_for(table_name, table_alias) - "#{table_name} #{table_alias if table_name != table_alias}".strip - end - - def table_name_and_alias - table_alias_for table_name, @aliased_table_name - end - - def interpolate_sql(sql) - instance_eval("%@#{sql.gsub('@', '\@')}@", __FILE__, __LINE__) - end - end - end end end end |