X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=vendor%2Frails%2Factiverecord%2Flib%2Factive_record%2Fassociations.rb;fp=vendor%2Frails%2Factiverecord%2Flib%2Factive_record%2Fassociations.rb;h=7f7819115cddbe8a7353539d1b0e6dc3c76b72aa;hb=d115f2e23823271635bad69229a42cd8ac68debe;hp=0000000000000000000000000000000000000000;hpb=37cb670bf3ddde90b214e591f100ed4446469484;p=depot.git diff --git a/vendor/rails/activerecord/lib/active_record/associations.rb b/vendor/rails/activerecord/lib/active_record/associations.rb new file mode 100755 index 0000000..7f78191 --- /dev/null +++ b/vendor/rails/activerecord/lib/active_record/associations.rb @@ -0,0 +1,2227 @@ +require 'active_record/associations/association_proxy' +require 'active_record/associations/association_collection' +require 'active_record/associations/belongs_to_association' +require 'active_record/associations/belongs_to_polymorphic_association' +require 'active_record/associations/has_one_association' +require 'active_record/associations/has_many_association' +require 'active_record/associations/has_many_through_association' +require 'active_record/associations/has_and_belongs_to_many_association' +require 'active_record/associations/has_one_through_association' + +module ActiveRecord + class HasManyThroughAssociationNotFoundError < ActiveRecordError #:nodoc: + def initialize(owner_class_name, reflection) + super("Could not find the association #{reflection.options[:through].inspect} in model #{owner_class_name}") + end + end + + class HasManyThroughAssociationPolymorphicError < 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 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 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 :connector => 'or'} in model #{through_reflection.klass}. Try 'has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}, :source => '. Is it one of #{source_associations.to_sentence :connector => 'or'}?") + 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.") + end + end + + class HasManyThroughCantAssociateThroughHasManyReflection < ActiveRecordError #:nodoc: + def initialize(owner, reflection) + super("Cannot modify association '#{owner.class.name}##{reflection.name}' because the source reflection class '#{reflection.source_reflection.class_name}' is associated to '#{reflection.through_reflection.class_name}' via :#{reflection.source_reflection.macro}.") + end + end + class HasManyThroughCantAssociateNewRecords < ActiveRecordError #:nodoc: + def initialize(owner, reflection) + super("Cannot associate new records through '#{owner.class.name}##{reflection.name}' on '#{reflection.source_reflection.class_name rescue nil}##{reflection.source_reflection.name rescue nil}'. Both records must have an id in order to create the has_many :through record associating them.") + end + end + + class HasManyThroughCantDissociateNewRecords < ActiveRecordError #:nodoc: + def initialize(owner, reflection) + super("Cannot dissociate new records through '#{owner.class.name}##{reflection.name}' on '#{reflection.source_reflection.class_name rescue nil}##{reflection.source_reflection.name rescue nil}'. Both records must have an id in order to delete the has_many :through record associating them.") + end + end + + class EagerLoadPolymorphicError < ActiveRecordError #:nodoc: + def initialize(reflection) + super("Can not eagerly load the polymorphic association #{reflection.name.inspect}") + end + end + + class ReadOnlyAssociation < ActiveRecordError #:nodoc: + def initialize(reflection) + super("Can not add to a has_many :through association. Try adding to #{reflection.through_reflection.name.inspect}.") + end + end + + # See ActiveRecord::Associations::ClassMethods for documentation. + module Associations # :nodoc: + def self.included(base) + base.extend(ClassMethods) + end + + # 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? + 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 options hash. It works much the same way as Ruby's own attr* + # methods. Example: + # + # class Project < ActiveRecord::Base + # belongs_to :portfolio + # has_one :project_manager + # has_many :milestones + # has_and_belongs_to_many :categories + # end + # + # The project class now has the following methods (and more) to ease the traversal and manipulation of its relationships: + # * Project#portfolio, Project#portfolio=(portfolio), Project#portfolio.nil? + # * Project#project_manager, Project#project_manager=(project_manager), Project#project_manager.nil?, + # * Project#milestones.empty?, Project#milestones.size, Project#milestones, Project#milestones<<(milestone), + # Project#milestones.delete(milestone), Project#milestones.find(milestone_id), Project#milestones.find(:all, options), + # Project#milestones.build, Project#milestones.create + # * Project#categories.empty?, Project#categories.size, Project#categories, Project#categories<<(category1), + # Project#categories.delete(category1) + # + # === A word of warning + # + # Don't create associations that have the same name as instance methods of ActiveRecord::Base. 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. + # + # == Auto-generated methods + # + # === Singular associations (one-to-one) + # | | belongs_to | + # generated methods | belongs_to | :polymorphic | has_one + # ----------------------------------+------------+--------------+--------- + # #other | X | X | X + # #other=(other) | X | X | X + # #build_other(attributes={}) | X | | X + # #create_other(attributes={}) | X | | X + # #other.create!(attributes={}) | | | X + # #other.nil? | X | X | + # + # ===Collection associations (one-to-many / many-to-many) + # | | | has_many + # generated methods | habtm | has_many | :through + # ----------------------------------+-------+----------+---------- + # #others | X | X | X + # #others=(other,other,...) | X | X | X + # #other_ids | X | X | X + # #other_ids=(id,id,...) | X | X | X + # #others<< | X | X | X + # #others.push | X | X | X + # #others.concat | X | X | X + # #others.build(attributes={}) | X | X | X + # #others.create(attributes={}) | X | X | X + # #others.create!(attributes={}) | X | X | X + # #others.size | X | X | X + # #others.length | X | X | X + # #others.count | X | X | X + # #others.sum(args*,&block) | X | X | X + # #others.empty? | X | X | X + # #others.clear | X | X | X + # #others.delete(other,other,...) | X | X | X + # #others.delete_all | X | X | + # #others.destroy_all | X | X | X + # #others.find(*args) | X | X | X + # #others.find_first | X | | + # #others.exist? | X | X | X + # #others.uniq | X | X | X + # #others.reset | X | X | X + # + # == Cardinality and associations + # + # Active Record associations can be used to describe one-to-one, one-to-many and many-to-many + # relationships between models. Each model uses an association to describe its role in + # the relation. The +belongs_to+ association is always used in the model that has + # the foreign key. + # + # === One-to-one + # + # Use +has_one+ in the base, and +belongs_to+ in the associated model. + # + # class Employee < ActiveRecord::Base + # has_one :office + # end + # class Office < ActiveRecord::Base + # belongs_to :employee # foreign key - employee_id + # end + # + # === One-to-many + # + # Use +has_many+ in the base, and +belongs_to+ in the associated model. + # + # class Manager < ActiveRecord::Base + # has_many :employees + # end + # class Employee < ActiveRecord::Base + # belongs_to :manager # foreign key - manager_id + # end + # + # === Many-to-many + # + # There are two ways to build a many-to-many relationship. + # + # The first way uses a +has_many+ association with the :through option and a join model, so + # there are two stages of associations. + # + # class Assignment < ActiveRecord::Base + # belongs_to :programmer # foreign key - programmer_id + # belongs_to :project # foreign key - project_id + # end + # class Programmer < ActiveRecord::Base + # has_many :assignments + # has_many :projects, :through => :assignments + # end + # class Project < ActiveRecord::Base + # has_many :assignments + # has_many :programmers, :through => :assignments + # end + # + # For the second way, use +has_and_belongs_to_many+ in both models. This requires a join table + # that has no corresponding model or primary key. + # + # class Programmer < ActiveRecord::Base + # has_and_belongs_to_many :projects # foreign keys in the join table + # end + # class Project < ActiveRecord::Base + # has_and_belongs_to_many :programmers # foreign keys in the join table + # end + # + # Choosing which way to build a many-to-many relationship is not always simple. + # If you need to work with the relationship model as its own entity, + # use has_many :through. Use +has_and_belongs_to_many+ when working with legacy schemas or when + # you never work directly with the relationship itself. + # + # == Is it a +belongs_to+ or +has_one+ association? + # + # 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. Example: + # + # class User < ActiveRecord::Base + # # I reference an account. + # belongs_to :account + # end + # + # class Account < ActiveRecord::Base + # # One user references me. + # has_one :user + # end + # + # The tables for these classes could look something like: + # + # CREATE TABLE users ( + # id int(11) NOT NULL auto_increment, + # account_id int(11) default NULL, + # name varchar default NULL, + # PRIMARY KEY (id) + # ) + # + # CREATE TABLE accounts ( + # id int(11) NOT NULL auto_increment, + # name varchar default NULL, + # PRIMARY KEY (id) + # ) + # + # == 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 associated objects. + # + # === 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 (new_record? == true). + # * 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 association.build 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. + # + # === 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 push or similar) fails, then push returns +false+. + # * You can add an object to a collection without automatically saving it by using the collection.build method (documented below). + # * All unsaved (new_record? == true) 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 object from an association collection. Example: + # + # class Project + # has_and_belongs_to_many :developers, :after_add => :evaluate_velocity + # + # def evaluate_velocity(developer) + # ... + # end + # end + # + # It's possible to stack callbacks by passing them as an array. Example: + # + # class Project + # 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 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 factory-type methods that are only used as part of this association. + # Example: + # + # class Account < ActiveRecord::Base + # has_many :people do + # def find_or_create_by_name(name) + # first_name, last_name = name.split(" ", 2) + # find_or_create_by_first_name_and_last_name(first_name, last_name) + # end + # end + # end + # + # person = Account.find(:first).people.find_or_create_by_name("David Heinemeier Hansson") + # 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. Example: + # + # module FindOrCreateByNameExtension + # def find_or_create_by_name(name) + # first_name, last_name = name.split(" ", 2) + # find_or_create_by_first_name_and_last_name(first_name, last_name) + # end + # end + # + # class Account < ActiveRecord::Base + # has_many :people, :extend => FindOrCreateByNameExtension + # end + # + # class Company < ActiveRecord::Base + # has_many :people, :extend => FindOrCreateByNameExtension + # end + # + # If you need to use multiple named extension modules, you can specify an array of modules with the :extend 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. Example: + # + # class Account < ActiveRecord::Base + # has_many :people, :extend => [FindOrCreateByNameExtension, FindRecentExtension] + # end + # + # Some extensions can only be made to work with knowledge of the association proxy's internals. + # Extensions can access relevant state using accessors on the association proxy: + # + # * +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 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 :through 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: + # + # class Author < ActiveRecord::Base + # has_many :authorships + # has_many :books, :through => :authorships + # end + # + # class Authorship < ActiveRecord::Base + # belongs_to :author + # belongs_to :book + # end + # + # @author = Author.find :first + # @author.authorships.collect { |a| a.book } # selects all books that the author's authorships belong to. + # @author.books # selects all books by using the Authorship join model + # + # You can also go through a +has_many+ association on the join model: + # + # class Firm < ActiveRecord::Base + # has_many :clients + # has_many :invoices, :through => :clients + # end + # + # class Client < ActiveRecord::Base + # belongs_to :firm + # has_many :invoices + # end + # + # class Invoice < ActiveRecord::Base + # belongs_to :client + # end + # + # @firm = Firm.find :first + # @firm.clients.collect { |c| c.invoices }.flatten # select all invoices for all clients of the firm + # @firm.invoices # selects all invoices by going through the Client join model. + # + # === 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 must adhere to. + # + # class Asset < ActiveRecord::Base + # belongs_to :attachable, :polymorphic => true + # end + # + # class Post < ActiveRecord::Base + # has_many :assets, :as => :attachable # The :as option specifies the polymorphic interface to use. + # end + # + # @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 +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 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+ column in the posts table. + # + # class Asset < ActiveRecord::Base + # belongs_to :attachable, :polymorphic => true + # + # def attachable_type=(sType) + # super(sType.to_s.classify.constantize.base_class.to_s) + # end + # end + # + # class Post < ActiveRecord::Base + # # because we store "Post" in attachable_type now :dependent => :destroy will work + # has_many :assets, :as => :attachable, :dependent => :destroy + # end + # + # class GuestPost < Post + # end + # + # class MemberPost < Post + # end + # + # == 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 shared across methods to make it even cheaper to use the macro-added methods without + # worrying too much about performance at the first go. Example: + # + # project.milestones # fetches milestones from the database + # project.milestones.size # uses the milestone cache + # project.milestones.empty? # uses the milestone cache + # project.milestones(true).size # fetches milestones from the database + # project.milestones # uses the milestone cache + # + # == 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 use of eager loading, the 101 queries can be reduced to 2. Example: + # + # class Post < ActiveRecord::Base + # belongs_to :author + # has_many :comments + # end + # + # Consider the following loop using the class above: + # + # for post in Post.all + # puts "Post: " + post.title + # puts "Written by: " + post.author.name + # 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 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 :author 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 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 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 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 used LEFT OUTER JOIN based strategy. For example + # + # Post.find(:all, :include => [ :author, :comments ], :conditions => ['comments.approved = ?', true]) + # + # will result in a single SQL query with joins along the lines of: LEFT OUTER JOIN comments ON comments.post_id = posts.id and + # LEFT OUTER JOIN authors ON authors.id = posts.author_id. 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. You must disambiguate column references for this fallback to happen, for example + # :order => "author.name DESC" will work but :order => "name DESC" will not. + # + # If you do want eagerload only some members of an association it is usually more natural to :include an association + # which has conditions defined on it: + # + # class Post < ActiveRecord::Base + # has_many :approved_comments, :class_name => 'Comment', :conditions => ['approved = ?', true] + # end + # + # Post.find(:all, :include => :approved_comments) + # + # 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 :limit option, it will be ignored, returning all the associated objects: + # + # class Picture < ActiveRecord::Base + # has_many :most_recent_comments, :class_name => 'Comment', :order => 'id DESC', :limit => 10 + # end + # + # 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 the model instance. Conditions are lazily interpolated + # before the actual model exists. + # + # Eager loading is supported with polymorphic associations. + # + # class Address < ActiveRecord::Base + # belongs_to :addressable, :polymorphic => true + # end + # + # A call that tries to eager load the addressable model + # + # Address.find(:all, :include => :addressable) + # + # 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 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 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 #{reflection_name}_#{parent_table_name}. Indexes are appended + # for any more successive uses of the table name. + # + # Post.find :all, :joins => :comments + # # => SELECT ... FROM posts INNER JOIN comments ON ... + # Post.find :all, :joins => :special_comments # STI + # # => SELECT ... FROM posts INNER JOIN comments ON ... AND comments.type = 'SpecialComment' + # Post.find :all, :joins => [:comments, :special_comments] # special_comments is the reflection name, posts is the parent table name + # # => SELECT ... FROM posts INNER JOIN comments ON ... INNER JOIN comments special_comments_posts + # + # Acts as tree example: + # + # TreeMixin.find :all, :joins => :children + # # => SELECT ... FROM mixins INNER JOIN mixins childrens_mixins ... + # TreeMixin.find :all, :joins => {:children => :parent} + # # => SELECT ... FROM mixins INNER JOIN mixins childrens_mixins ... + # INNER JOIN parents_mixins ... + # TreeMixin.find :all, :joins => {:children => {:parent => :children}} + # # => SELECT ... FROM mixins INNER JOIN mixins childrens_mixins ... + # INNER JOIN parents_mixins ... + # INNER JOIN mixins childrens_mixins_2 + # + # Has and Belongs to Many join tables use the same idea, but add a _join suffix: + # + # Post.find :all, :joins => :categories + # # => SELECT ... FROM posts INNER JOIN categories_posts ... INNER JOIN categories ... + # Post.find :all, :joins => {:categories => :posts} + # # => SELECT ... FROM posts INNER JOIN categories_posts ... INNER JOIN categories ... + # INNER JOIN categories_posts posts_categories_join INNER JOIN posts posts_categories + # Post.find :all, :joins => {:categories => {:posts => :categories}} + # # => SELECT ... FROM posts INNER JOIN categories_posts ... INNER JOIN categories ... + # 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 :joins option, those table names will take precedence over the eager associations: + # + # Post.find :all, :joins => :comments, :joins => "inner join comments ..." + # # => SELECT ... FROM posts INNER JOIN comments_posts ON ... INNER JOIN comments ... + # Post.find :all, :joins => [:comments, :special_comments], :joins => "inner join comments ..." + # # => SELECT ... FROM posts INNER JOIN comments comments_posts ON ... + # INNER JOIN comments special_comments_posts ... + # INNER JOIN comments ... + # + # Table aliases are automatically truncated according to the maximum length of table identifiers according to the specific database. + # + # == Modules + # + # By default, associations will look for objects within the current module scope. Consider: + # + # module MyApplication + # module Business + # class Firm < ActiveRecord::Base + # has_many :clients + # end + # + # class Client < ActiveRecord::Base; end + # end + # end + # + # When Firm#clients is called, it will in turn call MyApplication::Business::Client.find_all_by_firm_id(firm.id). + # If you want to associate with a class in another module scope, this can be done by specifying the complete class name. + # Example: + # + # module MyApplication + # module Business + # class Firm < ActiveRecord::Base; end + # end + # + # module Billing + # class Account < ActiveRecord::Base + # belongs_to :firm, :class_name => "MyApplication::Business::Firm" + # end + # end + # end + # + # == Type safety with ActiveRecord::AssociationTypeMismatch + # + # If you attempt to assign an object to an association that doesn't match the inferred or specified :class_name, you'll + # get an ActiveRecord::AssociationTypeMismatch. + # + # == Options + # + # 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 + # collections of associated objects will be added: + # + # [collection(force_reload = false)] + # Returns an array of all the associated objects. + # 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. + # [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 :dependent => :destroy, + # and deleted if they're associated with :dependent => :delete_all. + # [collection=objects] + # Replaces the collections content by deleting and adding objects as appropriate. + # [collection_singular_ids] + # Returns an array of the associated objects' ids + # [collection_singular_ids=ids] + # Replace the collection with the objects identified by the primary keys in +ids+ + # [collection.clear] + # Removes every object from the collection. This destroys the associated objects if they + # are associated with :dependent => :destroy, deletes them directly from the + # database if :dependent => :delete_all, otherwise sets their foreign keys to +NULL+. + # [collection.empty?] + # Returns +true+ if there are no associated objects. + # [collection.size] + # Returns the number of associated objects. + # [collection.find(...)] + # Finds an associated object according to the same rules as ActiveRecord::Base.find. + # [collection.exist?(...)] + # Checks whether an associated object with the given conditions exists. + # Uses the same rules as ActiveRecord::Base.exists?. + # [collection.build(attributes = {}, ...)] + # Returns one or more new objects of the collection type that have been instantiated + # with +attributes+ and linked to this object through a foreign key, but have not yet + # been saved. Note: This only works if an associated object already exists, not if + # it's +nil+! + # [collection.create(attributes = {})] + # Returns a new object of the collection 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). Note: This only works if an associated + # object already exists, not if it's +nil+! + # + # (*Note*: +collection+ is replaced with the symbol passed as the first argument, so + # has_many :clients would add among others clients.empty?.) + # + # === Example + # + # Example: A Firm class declares has_many :clients, which will add: + # * Firm#clients (similar to Clients.find :all, :conditions => ["firm_id = ?", id]) + # * Firm#clients<< + # * Firm#clients.delete + # * Firm#clients= + # * Firm#client_ids + # * Firm#client_ids= + # * Firm#clients.clear + # * Firm#clients.empty? (similar to firm.clients.size == 0) + # * Firm#clients.size (similar to Client.count "firm_id = #{id}") + # * Firm#clients.find (similar to Client.find(id, :conditions => "firm_id = #{id}")) + # * Firm#clients.exist?(:name => 'ACME') (similar to Client.exist?(:name => 'ACME', :firm_id => firm.id)) + # * Firm#clients.build (similar to Client.new("firm_id" => id)) + # * Firm#clients.create (similar to c = Client.new("firm_id" => id); c.save; c) + # The declaration can also include an options hash to specialize the behavior of the association. + # + # === Supported 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 has_many :products 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 price > 5 AND name LIKE 'B%'. Record creations from the association are scoped if a hash + # is used. has_many :posts, :conditions => {:published => true} will create published posts with @blog.posts.create + # or @blog.posts.build. + # [:order] + # Specify the order in which the associated objects are returned as an ORDER BY SQL fragment, + # such as last_name, first_name DESC. + # [: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+ association will use "person_id" + # as the default :foreign_key. + # [:primary_key] + # Specify the method that returns the primary key used for the association. By default this is +id+. + # [:dependent] + # If set to :destroy all the associated objects are destroyed + # alongside this object by calling their +destroy+ method. If set to :delete_all all associated + # objects are deleted *without* calling their +destroy+ method. If set to :nullify all associated + # objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. *Warning:* This option is ignored when also using + # the :through option. + # [: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+ is _not_ added. + # [:counter_sql] + # Specify a complete SQL statement to fetch the size of the association. If :finder_sql is + # specified but not :counter_sql, :counter_sql will be generated by replacing SELECT ... FROM with SELECT COUNT(*) FROM. + # [:extend] + # Specify a named module for extending the proxy. See "Association extensions". + # [:include] + # Specify second-order associations that should be eager loaded when the collection is loaded. + # [:group] + # An attribute name by which the result should be grouped. Uses the GROUP BY 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, it would skip the first 4 rows. + # [:select] + # By default, this is * as in SELECT * FROM, 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 belongs_to). + # [:through] + # Specifies a Join Model through which to perform the query. Options for :class_name and :foreign_key + # are ignored, as the association uses the source reflection. You can only use a :through query through a belongs_to + # or has_many association on the join model. + # [:source] + # Specifies the source association name used by has_many :through queries. Only use it if the name cannot be + # inferred from the association. has_many :subscribers, :through => :subscriptions will look for either :subscribers or + # :subscriber on Subscription, unless a :source is given. + # [:source_type] + # Specifies type of the source association used by has_many :through queries where the source + # association is a polymorphic +belongs_to+. + # [:uniq] + # If true, duplicates will be omitted from the collection. Useful in conjunction with :through. + # [: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. + # Option examples: + # has_many :comments, :order => "posted_on" + # has_many :comments, :include => :author + # has_many :people, :class_name => "Person", :conditions => "deleted = 0", :order => "name" + # has_many :tracks, :order => "position", :dependent => :destroy + # has_many :comments, :dependent => :nullify + # has_many :tags, :as => :taggable + # has_many :reports, :readonly => true + # has_many :subscribers, :through => :subscriptions, :source => :user + # has_many :subscribers, :class_name => "Person", :finder_sql => + # 'SELECT DISTINCT people.* ' + + # '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_multiple_associated_validation_callbacks(reflection.name) unless options[:validate] == false + add_multiple_associated_save_callbacks(reflection.name) + add_association_callbacks(reflection.name, reflection.options) + + if options[:through] + collection_accessor_methods(reflection, HasManyThroughAssociation) + else + collection_accessor_methods(reflection, HasManyAssociation) + end + end + + # Specifies a one-to-one association with another class. This method should only be used + # if the other class contains the foreign key. If the current class contains the foreign key, + # then you should use +belongs_to+ instead. See also ActiveRecord::Associations::ClassMethods's overview + # on when to use has_one and when to use belongs_to. + # + # The following methods for retrieval and query of a single associated object will be added: + # + # [association(force_reload = false)] + # Returns the associated object. +nil+ is returned if none is found. + # [association=(associate)] + # Assigns the associate object, extracts the primary key, sets it as the foreign key, + # and saves the associate object. + # [association.nil?] + # Returns +true+ if there is no associated object. + # [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. Note: This ONLY works if an association already exists. + # It will NOT work if the association is +nil+. + # [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). + # + # (+association+ is replaced with the symbol passed as the first argument, so + # has_one :manager would add among others manager.nil?.) + # + # === Example + # + # An Account class declares has_one :beneficiary, which will add: + # * Account#beneficiary (similar to Beneficiary.find(:first, :conditions => "account_id = #{id}")) + # * Account#beneficiary=(beneficiary) (similar to beneficiary.account_id = account.id; beneficiary.save) + # * Account#beneficiary.nil? + # * Account#build_beneficiary (similar to Beneficiary.new("account_id" => id)) + # * Account#create_beneficiary (similar to b = Beneficiary.new("account_id" => id); b.save; b) + # + # === Options + # + # The declaration can also include an options hash to specialize the behavior of the association. + # + # Options are: + # [:class_name] + # Specify the class name of the association. Use it only if that name can't be inferred + # from the association name. So has_one :manager will by default be linked to the Manager class, but + # if the real class name is Person, you'll have to specify it with this option. + # [:conditions] + # Specify the conditions that the associated object must meet in order to be included as a +WHERE+ + # SQL fragment, such as rank = 5. + # [:order] + # Specify the order in which the associated objects are returned as an ORDER BY SQL fragment, + # such as last_name, first_name DESC. + # [:dependent] + # If set to :destroy, the associated object is destroyed when this object is. If set to + # :delete, the associated object is deleted *without* calling its destroy method. If set to :nullify, 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 will use "person_id" + # as the default :foreign_key. + # [:primary_key] + # Specify the method that returns the primary key used for the association. By default this is +id+. + # [:include] + # Specify second-order associations that should be eager loaded when this object is loaded. + # [:as] + # Specifies a polymorphic interface (See belongs_to). + # [:select] + # By default, this is * as in SELECT * FROM, 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 :class_name and :foreign_key + # are ignored, as the association uses the source reflection. You can only use a :through query through a + # has_one or belongs_to association on the join model. + # [:source] + # Specifies the source association name used by has_one :through queries. Only use it if the name cannot be + # inferred from the association. has_one :favorite, :through => :favorites will look for a + # :favorite on Favorite, unless a :source is given. + # [:source_type] + # Specifies type of the source association used by has_one :through queries where the source + # association is a polymorphic +belongs_to+. + # [: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. + # + # Option examples: + # has_one :credit_card, :dependent => :destroy # destroys the associated credit card + # 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'" + # has_one :attachment, :as => :attachable + # 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) + + ivar = "@#{reflection.name}" + + method_name = "has_one_after_save_for_#{reflection.name}".to_sym + define_method(method_name) do + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + if !association.nil? && (new_record? || association.new_record? || association[reflection.primary_key_name] != id) + association[reflection.primary_key_name] = id + association.save(true) + end + end + after_save method_name + + add_single_associated_validation_callbacks(reflection.name) if options[:validate] == true + association_accessor_methods(reflection, HasOneAssociation) + association_constructor_method(:build, reflection, HasOneAssociation) + association_constructor_method(:create, reflection, HasOneAssociation) + + configure_dependency_for_has_one(reflection) + end + end + + # Specifies a one-to-one association with another class. This method should only be used + # if this class contains the foreign key. If the other class contains the foreign key, + # then you should use +has_one+ instead. See also ActiveRecord::Associations::ClassMethods's overview + # on when to use +has_one+ and when to use +belongs_to+. + # + # Methods will be added for retrieval and query for a single associated object, for which + # this object holds an id: + # + # [association(force_reload = false)] + # Returns the associated object. +nil+ is returned if none is found. + # [association=(associate)] + # Assigns the associate object, extracts the primary key, and sets it as the foreign key. + # [association.nil?] + # Returns +true+ if there is no associated object. + # [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. + # [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). + # + # (+association+ is replaced with the symbol passed as the first argument, so + # belongs_to :author would add among others author.nil?.) + # + # === Example + # + # A Post class declares belongs_to :author, which will add: + # * Post#author (similar to Author.find(author_id)) + # * Post#author=(author) (similar to post.author_id = author.id) + # * Post#author? (similar to post.author == some_author) + # * Post#author.nil? + # * Post#build_author (similar to post.author = Author.new) + # * Post#create_author (similar to post.author = Author.new; post.author.save; post.author) + # The declaration can also include an options hash to specialize the behavior of the association. + # + # === 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 has_one :author will by default be linked to the Author class, but + # if the real class name is Person, you'll have to specify it with this option. + # [:conditions] + # Specify the conditions that the associated object must meet in order to be included as a +WHERE+ + # SQL fragment, such as authorized = 1. + # [:select] + # By default, this is * as in SELECT * FROM, 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 belongs_to :person association will use + # "person_id" as the default :foreign_key. Similarly, belongs_to :favorite_person, :class_name => "Person" + # will use a foreign key of "favorite_person_id". + # [:dependent] + # If set to :destroy, the associated object is destroyed when this object is. If set to + # :delete, the associated object is deleted *without* calling its destroy method. This option should not be specified when + # belongs_to is used in conjunction with a has_many 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 named #{table_name}_count (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 option (e.g., :counter_cache => :my_custom_counter.) + # 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. + # [:polymorphic] + # Specify this association is a polymorphic association by passing +true+. + # Note: If you've enabled the counter cache, then you may want to add the counter cache attribute + # to the +attr_readonly+ list in the associated classes (e.g. class Post; attr_readonly :comments_count; end). + # [: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. + # + # Option examples: + # belongs_to :firm, :foreign_key => "client_of" + # belongs_to :author, :class_name => "Person", :foreign_key => "author_id" + # belongs_to :valid_coupon, :class_name => "Coupon", :foreign_key => "coupon_id", + # :conditions => 'discounts > #{payments_count}' + # belongs_to :attachable, :polymorphic => true + # belongs_to :project, :readonly => true + # belongs_to :post, :counter_cache => true + def belongs_to(association_id, options = {}) + reflection = create_belongs_to_reflection(association_id, options) + + ivar = "@#{reflection.name}" + + if reflection.options[:polymorphic] + association_accessor_methods(reflection, BelongsToPolymorphicAssociation) + + method_name = "polymorphic_belongs_to_before_save_for_#{reflection.name}".to_sym + define_method(method_name) do + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + if association && association.target + if association.new_record? + association.save(true) + end + + if association.updated? + self[reflection.primary_key_name] = association.id + self[reflection.options[:foreign_type]] = association.class.base_class.name.to_s + end + end + end + before_save method_name + else + association_accessor_methods(reflection, BelongsToAssociation) + association_constructor_method(:build, reflection, BelongsToAssociation) + association_constructor_method(:create, reflection, BelongsToAssociation) + + method_name = "belongs_to_before_save_for_#{reflection.name}".to_sym + define_method(method_name) do + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + if !association.nil? + if association.new_record? + association.save(true) + end + + if association.updated? + self[reflection.primary_key_name] = association.id + end + end + end + before_save method_name + end + + # Create the callbacks to update counter cache + if options[:counter_cache] + cache_column = options[:counter_cache] == true ? + "#{self.to_s.demodulize.underscore.pluralize}_count" : + options[:counter_cache] + + 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, send(reflection.primary_key_name)) 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, send(reflection.primary_key_name)) 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)" + ) + end + + add_single_associated_validation_callbacks(reflection.name) if options[:validate] == true + + configure_dependency_for_belongs_to(reflection) + 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 < 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", + # but it in fact generates a join table name of "paper_boxes_papers". Be aware of this caveat, and use the + # custom :join_table option if you need to. + # + # 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)] + # Returns an array of all the associated objects. + # An empty array is returned if none are found. + # [collection<<(object, ...)] + # Adds one or more objects to the collection by creating associations in the join table + # (collection.push and collection.concat are aliases to this method). + # [collection.delete(object, ...)] + # Removes one or more objects from the collection by removing their associations from the join table. + # This does not destroy the objects. + # [collection=objects] + # Replaces the collection's content by deleting and adding objects as appropriate. + # [collection_singular_ids] + # Returns an array of the associated objects' ids. + # [collection_singular_ids=ids] + # Replace the collection by the objects identified by the primary keys in +ids+. + # [collection.clear] + # Removes every object from the collection. This does not destroy the objects. + # [collection.empty?] + # Returns +true+ if there are no associated objects. + # [collection.size] + # Returns the number of associated objects. + # [collection.find(id)] + # Finds an associated object responding to the +id+ and that + # meets the condition that it has to be associated with this object. + # Uses the same rules as ActiveRecord::Base.find. + # [collection.exist?(...)] + # Checks whether an associated object with the given conditions exists. + # Uses the same rules as ActiveRecord::Base.exists?. + # [collection.build(attributes = {})] + # Returns a new object of the collection type that has been instantiated + # with +attributes+ and linked to this object through the join table, but has not yet been saved. + # [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 saved (if it passed the validation). + # + # (+collection+ is replaced with the symbol passed as the first argument, so + # has_and_belongs_to_many :categories would add among others categories.empty?.) + # + # === Example + # + # A Developer class declares has_and_belongs_to_many :projects, which will add: + # * Developer#projects + # * Developer#projects<< + # * Developer#projects.delete + # * Developer#projects= + # * Developer#project_ids + # * Developer#project_ids= + # * Developer#projects.clear + # * Developer#projects.empty? + # * Developer#projects.size + # * Developer#projects.find(id) + # * Developer#clients.exist?(...) + # * Developer#projects.build (similar to Project.new("project_id" => id)) + # * Developer#projects.create (similar to c = Project.new("project_id" => id); c.save; c) + # The declaration may include an options hash to specialize the behavior of the association. + # + # === 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 has_and_belongs_to_many :projects will by default be linked to the + # Project class, but if the real class name is SuperProject, you'll have to specify it with this option. + # [:join_table] + # Specify the name of the join table if the default based on lexical order isn't what you want. + # WARNING: If you're overwriting the table name of either class, the +table_name+ method + # 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 + # will use "person_id" as the default :foreign_key. + # [:association_foreign_key] + # Specify the association foreign key used for the association. By default this is + # guessed to be the name of the associated class in lower-case and "_id" suffixed. So if the associated class is Project, + # the +has_and_belongs_to_many+ association will use "project_id" as the default :association_foreign_key. + # [:conditions] + # Specify the conditions that the associated object must meet in order to be included as a +WHERE+ + # SQL fragment, such as authorized = 1. Record creations from the association are scoped if a hash is used. + # has_many :posts, :conditions => {:published => true} will create published posts with @blog.posts.create + # or @blog.posts.build. + # [:order] + # Specify the order in which the associated objects are returned as an ORDER BY SQL fragment, + # such as last_name, first_name DESC + # [:uniq] + # If true, duplicate associated objects will be ignored by accessors and query methods. + # [:finder_sql] + # 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 :finder_sql is + # specified but not :counter_sql, :counter_sql will be generated by replacing SELECT ... FROM with SELECT COUNT(*) FROM. + # [:delete_sql] + # Overwrite the default generated SQL statement used to remove links between the associated + # classes with a manual statement. + # [:insert_sql] + # Overwrite the default generated SQL statement used to add links between the associated classes + # with a manual statement. + # [:extend] + # Anonymous module for extending the proxy, see "Association extensions". + # [:include] + # Specify second-order associations that should be eager loaded when the collection is loaded. + # [:group] + # An attribute name by which the result should be grouped. Uses the GROUP BY 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, it would skip the first 4 rows. + # [:select] + # By default, this is * as in SELECT * FROM, 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. + # + # Option examples: + # has_and_belongs_to_many :projects + # has_and_belongs_to_many :projects, :include => [ :milestones, :manager ] + # has_and_belongs_to_many :nations, :class_name => "Country" + # has_and_belongs_to_many :categories, :join_table => "prods_cats" + # 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) + + add_multiple_associated_validation_callbacks(reflection.name) unless options[:validate] == false + add_multiple_associated_save_callbacks(reflection.name) + 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. + old_method = "destroy_without_habtm_shim_for_#{reflection.name}" + class_eval <<-end_eval unless method_defined?(old_method) + alias_method :#{old_method}, :destroy_without_callbacks + def destroy_without_callbacks + #{reflection.name}.clear + #{old_method} + end + end_eval + + add_association_callbacks(reflection.name, options) + end + + private + # Generates a join table name from two provided table names. + # The names in the join table namesme 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) + ivar = "@#{reflection.name}" + + define_method(reflection.name) do |*params| + force_reload = params.first unless params.empty? + + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + if association.nil? || force_reload + association = association_proxy_class.new(self, reflection) + retval = association.reload + if retval.nil? and association_proxy_class == BelongsToAssociation + instance_variable_set(ivar, nil) + return nil + end + instance_variable_set(ivar, association) + end + + association.target.nil? ? nil : association + end + + define_method("loaded_#{reflection.name}?") do + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + association && association.loaded? + end + + define_method("#{reflection.name}=") do |new_value| + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + if association.nil? || association.target != new_value + association = association_proxy_class.new(self, reflection) + end + + if association_proxy_class == HasOneThroughAssociation + association.create_through_record(new_value) + self.send(reflection.name, new_value) + else + association.replace(new_value) + instance_variable_set(ivar, new_value.nil? ? nil : association) + end + end + + define_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 + instance_variable_set(ivar, association) + end + end + + def collection_reader_method(reflection, association_proxy_class) + define_method(reflection.name) do |*params| + ivar = "@#{reflection.name}" + + force_reload = params.first unless params.empty? + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + unless association.respond_to?(:loaded?) + association = association_proxy_class.new(self, reflection) + instance_variable_set(ivar, association) + end + + association.reload if force_reload + + association + end + + define_method("#{reflection.name.to_s.singularize}_ids") do + if send(reflection.name).loaded? || reflection.options[:finder_sql] + send(reflection.name).map(&:id) + else + send(reflection.name).all(:select => "#{reflection.quoted_table_name}.#{reflection.klass.primary_key}").map(&:id) + end + end + end + + def collection_accessor_methods(reflection, association_proxy_class, writer = true) + collection_reader_method(reflection, association_proxy_class) + + if writer + define_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 + + define_method("#{reflection.name.to_s.singularize}_ids=") do |new_value| + ids = (new_value || []).reject { |nid| nid.blank? } + send("#{reflection.name}=", reflection.class_name.constantize.find(ids)) + end + end + end + + def add_single_associated_validation_callbacks(association_name) + method_name = "validate_associated_records_for_#{association_name}".to_sym + define_method(method_name) do + association = instance_variable_get("@#{association_name}") + if !association.nil? + errors.add association_name unless association.target.nil? || association.valid? + end + end + + validate method_name + end + + def add_multiple_associated_validation_callbacks(association_name) + method_name = "validate_associated_records_for_#{association_name}".to_sym + ivar = "@#{association_name}" + + define_method(method_name) do + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + if association.respond_to?(:loaded?) + if new_record? + association + elsif association.loaded? + association.select { |record| record.new_record? } + else + association.target.select { |record| record.new_record? } + end.each do |record| + errors.add association_name unless record.valid? + end + end + end + + validate method_name + end + + def add_multiple_associated_save_callbacks(association_name) + ivar = "@#{association_name}" + + method_name = "before_save_associated_records_for_#{association_name}".to_sym + define_method(method_name) do + @new_record_before_save = new_record? + true + end + before_save method_name + + method_name = "after_create_or_update_associated_records_for_#{association_name}".to_sym + define_method(method_name) do + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + records_to_save = if @new_record_before_save + association + elsif association.respond_to?(:loaded?) && association.loaded? + association.select { |record| record.new_record? } + elsif association.respond_to?(:loaded?) && !association.loaded? + association.target.select { |record| record.new_record? } + else + [] + end + records_to_save.each { |record| association.send(:insert_record, record) } unless records_to_save.blank? + + # reconstruct the SQL queries now that we know the owner's id + association.send(:construct_sql) if association.respond_to?(:construct_sql) + end + + # Doesn't use after_save as that would save associations added in after_create/after_update twice + after_create method_name + after_update method_name + end + + def association_constructor_method(constructor, reflection, association_proxy_class) + define_method("#{constructor}_#{reflection.name}") do |*params| + ivar = "@#{reflection.name}" + + attributees = params.first unless params.empty? + replace_existing = params[1].nil? ? true : params[1] + association = instance_variable_get(ivar) if instance_variable_defined?(ivar) + + if association.nil? + association = association_proxy_class.new(self, reflection) + instance_variable_set(ivar, association) + end + + if association_proxy_class == HasOneAssociation + association.send(constructor, attributees, replace_existing) + else + association.send(constructor, attributees) + end + end + end + + def find_with_associations(options = {}) + catch :invalid_query do + join_dependency = JoinDependency.new(self, merge_includes(scope(:find, :include), options[:include]), options[:joins]) + rows = select_all_rows(options, join_dependency) + return join_dependency.instantiate(rows) + end + [] + 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. Dependent associations + # delete children, otherwise foreign key is set to NULL. + # + # 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) + # Add polymorphic type if the :as option is present + dependent_conditions = [] + dependent_conditions << "#{reflection.primary_key_name} = \#{record.quoted_id}" + dependent_conditions << "#{reflection.options[:as]}_type = '#{base_class.name}'" if reflection.options[:as] + dependent_conditions << sanitize_sql(reflection.options[:conditions]) if reflection.options[:conditions] + dependent_conditions << extra_conditions if extra_conditions + dependent_conditions = dependent_conditions.collect {|where| "(#{where})" }.join(" AND ") + + 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 { |o| o.destroy } + end + before_destroy method_name + when :delete_all + module_eval %Q{ + before_destroy do |record| + delete_all_has_many_dependencies(record, + "#{reflection.name}", + #{reflection.class_name}, + "#{dependent_conditions}") + end + } + when :nullify + module_eval %Q{ + before_destroy do |record| + nullify_has_many_dependencies(record, + "#{reflection.name}", + #{reflection.class_name}, + "#{reflection.primary_key_name}", + "#{dependent_conditions}") + end + } + else + raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, or :nullify (#{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. + def configure_dependency_for_has_one(reflection) + if reflection.options.include?(:dependent) + case reflection.options[:dependent] + when :destroy + method_name = "has_one_dependent_destroy_for_#{reflection.name}".to_sym + define_method(method_name) do + association = send(reflection.name) + association.destroy unless association.nil? + end + before_destroy method_name + when :delete + method_name = "has_one_dependent_delete_for_#{reflection.name}".to_sym + define_method(method_name) do + # Retrieve the associated object and delete it. The retrieval + # is necessary because there may be multiple associated objects + # with foreign keys pointing to this object, and we only want + # to delete the correct one, not all of them. + association = send(reflection.name) + association.delete unless association.nil? + end + before_destroy method_name + when :nullify + method_name = "has_one_dependent_nullify_for_#{reflection.name}".to_sym + define_method(method_name) do + association = send(reflection.name) + association.update_attribute(reflection.primary_key_name, nil) unless association.nil? + end + before_destroy method_name + else + raise ArgumentError, "The :dependent option expects either :destroy, :delete or :nullify (#{reflection.options[:dependent].inspect})" + end + end + end + + def configure_dependency_for_belongs_to(reflection) + if reflection.options.include?(:dependent) + case reflection.options[:dependent] + when :destroy + method_name = "belongs_to_dependent_destroy_for_#{reflection.name}".to_sym + define_method(method_name) do + association = send(reflection.name) + association.destroy unless association.nil? + end + before_destroy method_name + when :delete + method_name = "belongs_to_dependent_delete_for_#{reflection.name}".to_sym + define_method(method_name) do + association = send(reflection.name) + association.delete unless association.nil? + end + before_destroy method_name + else + raise ArgumentError, "The :dependent option expects either :destroy or :delete (#{reflection.options[:dependent].inspect})" + end + 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, :limit, :offset, + :as, :through, :source, :source_type, + :uniq, + :finder_sql, :counter_sql, + :before_add, :after_add, :before_remove, :after_remove, + :extend, :readonly, + :validate + ] + + 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 + ] + + 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, :foreign_key, :foreign_type, :remote, :select, :conditions, + :include, :dependent, :counter_cache, :extend, :polymorphic, :readonly, + :validate + ] + + 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, :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) + + reflection.options[:join_table] ||= join_table_name(undecorated_table_name(self.to_s), undecorated_table_name(reflection.class_name)) + + reflection + end + + def reflect_on_included_associations(associations) + [ associations ].flatten.collect { |association| reflect_on_association(association.to_s.intern) } + end + + def guard_against_unlimitable_reflections(reflections, options) + if (options[:offset] || options[:limit]) && !using_limitable_reflections?(reflections) + raise( + ConfigurationError, + "You can not use offset and limit together with has_many or has_and_belongs_to_many associations" + ) + end + end + + def select_all_rows(options, join_dependency) + connection.select_all( + construct_finder_sql_with_included_associations(options, join_dependency), + "#{name} Load Including Associations" + ) + end + + def construct_finder_sql_with_included_associations(options, join_dependency) + scope = scope(:find) + sql = "SELECT #{column_aliases(join_dependency)} FROM #{(scope && scope[:from]) || options[:from] || quoted_table_name} " + sql << join_dependency.join_associations.collect{|join| join.association_join }.join + + add_joins!(sql, options[:joins], scope) + add_conditions!(sql, options[:conditions], scope) + add_limited_ids_condition!(sql, options, join_dependency) if !using_limitable_reflections?(join_dependency.reflections) && ((scope && scope[:limit]) || options[:limit]) + + add_group!(sql, options[:group], scope) + add_order!(sql, options[:order], scope) + add_limit!(sql, options, scope) if using_limitable_reflections?(join_dependency.reflections) + add_lock!(sql, options, scope) + + return sanitize_sql(sql) + end + + def add_limited_ids_condition!(sql, options, join_dependency) + unless (id_list = select_limited_ids_list(options, join_dependency)).empty? + sql << "#{condition_word(sql)} #{connection.quote_table_name table_name}.#{primary_key} IN (#{id_list}) " + else + throw :invalid_query + end + end + + def select_limited_ids_list(options, join_dependency) + pk = columns_hash[primary_key] + + connection.select_all( + construct_finder_sql_for_association_limiting(options, join_dependency), + "#{name} Load IDs For Limited Eager Loading" + ).collect { |row| connection.quote(row[primary_key], pk) }.join(", ") + end + + def construct_finder_sql_for_association_limiting(options, join_dependency) + scope = scope(:find) + + # Only join tables referenced in order or conditions since this is particularly slow on the pre-query. + tables_from_conditions = conditions_tables(options) + tables_from_order = order_tables(options) + all_tables = tables_from_conditions + tables_from_order + distinct_join_associations = all_tables.uniq.map{|table| + join_dependency.joins_for_table_name(table) + }.flatten.compact.uniq + + order = options[:order] + if scoped_order = (scope && scope[:order]) + order = order ? "#{order}, #{scoped_order}" : scoped_order + end + + is_distinct = !options[:joins].blank? || include_eager_conditions?(options, tables_from_conditions) || include_eager_order?(options, tables_from_order) + sql = "SELECT " + if is_distinct + sql << connection.distinct("#{connection.quote_table_name table_name}.#{primary_key}", order) + else + sql << primary_key + end + sql << " FROM #{connection.quote_table_name table_name} " + + if is_distinct + sql << distinct_join_associations.collect { |assoc| assoc.association_join }.join + add_joins!(sql, options[:joins], scope) + end + + add_conditions!(sql, options[:conditions], scope) + add_group!(sql, options[:group], scope) + + if order && is_distinct + connection.add_order_by_for_association_limiting!(sql, :order => order) + else + add_order!(sql, options[:order], scope) + end + + add_limit!(sql, options, scope) + + return sanitize_sql(sql) + end + + def conditions_tables(options) + # look in both sets of conditions + conditions = [scope(:find, :conditions), options[:conditions]].inject([]) do |all, cond| + case cond + when nil then all + when Array then all << cond.first + else all << cond + end + end + conditions.join(' ').scan(/([\.a-zA-Z_]+).?\./).flatten + end + + def order_tables(options) + order = [options[:order], scope(:find, :order) ].join(", ") + return [] unless order && order.is_a?(String) + order.scan(/([\.a-zA-Z_]+).?\./).flatten + end + + def selects_tables(options) + select = options[:select] + return [] unless select && select.is_a?(String) + select.scan(/"?([\.a-zA-Z_]+)"?.?\./).flatten + end + + # Checks if the conditions reference a table other than the current model table + def include_eager_conditions?(options, tables = nil) + ((tables || conditions_tables(options)) - [table_name]).any? + end + + # Checks if the query order references a table other than the current model's table. + def include_eager_order?(options, tables = nil) + ((tables || order_tables(options)) - [table_name]).any? + end + + def include_eager_select?(options) + (selects_tables(options) - [table_name]).any? + end + + def references_eager_loaded_tables?(options) + include_eager_order?(options) || include_eager_conditions?(options) || include_eager_select?(options) + end + + def using_limitable_reflections?(reflections) + reflections.reject { |r| [ :belongs_to, :has_one ].include?(r.macro) }.length.zero? + end + + def column_aliases(join_dependency) + join_dependency.joins.collect{|join| join.column_names_with_alias.collect{|column_name, aliased_name| + "#{connection.quote_table_name join.aliased_table_name}.#{connection.quote_column_name column_name} AS #{aliased_name}"}}.flatten.join(", ") + 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 condition_word(sql) + sql =~ /where/i ? " AND " : "WHERE " + 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(extensions).push("#{self.parent}::#{extension_module_name}".constantize) + else + Array(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 join_associations + @joins[1..-1].to_a + end + + def join_base + @joins[0] + 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] + if reflection && [:has_many, :has_and_belongs_to_many].include?(reflection.macro) + records.each { |record| record.send(reflection.name).target.uniq! } + end + when Array + associations.each do |association| + remove_duplicate_results!(base, records, association) + end + when Hash + associations.keys.each do |name| + reflection = base.reflections[name] + is_collection = [:has_many, :has_and_belongs_to_many].include?(reflection.macro) + + parent_records = records.map do |record| + descendant = record.send(reflection.name) + next unless descendant + descendant.target.uniq! if is_collection + descendant + end.flatten.compact + + remove_duplicate_results!(reflection.class_name.constantize, parent_records, associations[name]) unless parent_records.empty? + end + end + end + + def join_for_table_name(table_name) + join = (@joins.select{|j|j.aliased_table_name == table_name.gsub(/^\"(.*)\"$/){$1} }.first) rescue nil + return join unless join.nil? + @joins.select{|j|j.is_a?(JoinAssociation) && j.aliased_join_table_name == table_name.gsub(/^\"(.*)\"$/){$1} }.first rescue nil + end + + def joins_for_table_name(table_name) + join = join_for_table_name(table_name) + result = nil + if join && join.is_a?(JoinAssociation) + result = [join] + if join.parent && join.parent.is_a?(JoinAssociation) + result = joins_for_table_name(join.parent.aliased_table_name) + + result + end + end + result + end + + protected + def build(associations, parent = nil) + 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) + when Array + associations.each do |association| + build(association, parent) + end + when Hash + associations.keys.sort{|a,b|a.to_s<=>b.to_s}.each do |name| + build(name, parent) + build(associations[name]) + end + else + raise ConfigurationError, associations.inspect + end + end + + # overridden in InnerJoinDependency subclass + def build_join_association(reflection, parent) + JoinAssociation.new(reflection, self, parent) + end + + def construct(parent, associations, joins, row) + case associations + when Symbol, String + while (join = joins.shift).reflection.name.to_s != associations.to_s + raise ConfigurationError, "Not Enough Associations" if joins.empty? + end + 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| + association = construct_association(parent, joins.shift, row) + 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) + 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? + record.send("set_#{join.reflection.name}_target", association) + 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) + record.send("set_#{join.reflection.name}_target", association) + else + raise ConfigurationError, "unknown macro: #{join.reflection.macro}" + end + return association + end + + class JoinBase # :nodoc: + attr_reader :active_record, :table_joins + delegate :table_name, :column_names, :primary_key, :reflections, :sanitize_sql, :to => :active_record + + def initialize(active_record, joins = nil) + @active_record = active_record + @cached_record = {} + @table_joins = 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 + 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) + + 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 association_join + connection = reflection.active_record.connection + join = case reflection.macro + when :has_and_belongs_to_many + " #{join_type} %s ON %s.%s = %s.%s " % [ + table_alias_for(options[:join_table], aliased_join_table_name), + connection.quote_table_name(aliased_join_table_name), + options[:foreign_key] || reflection.active_record.to_s.foreign_key, + connection.quote_table_name(parent.aliased_table_name), + reflection.active_record.primary_key] + + " #{join_type} %s ON %s.%s = %s.%s " % [ + table_name_and_alias, + connection.quote_table_name(aliased_table_name), + klass.primary_key, + connection.quote_table_name(aliased_join_table_name), + options[:association_foreign_key] || klass.to_s.foreign_key + ] + when :has_many, :has_one + case + when reflection.options[:through] + through_conditions = through_reflection.options[:conditions] ? "AND #{interpolate_sql(sanitize_sql(through_reflection.options[:conditions]))}" : '' + + 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 = " AND %s.%s = %s" % [ + connection.quote_table_name(aliased_join_table_name), + connection.quote_column_name(through_reflection.options[:as].to_s + '_type'), + klass.quote_value(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 = " AND %s.%s = %s" % [ + connection.quote_table_name(aliased_table_name), + connection.quote_column_name("#{source_reflection.options[:as]}_type"), + klass.quote_value(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 = " AND %s.%s = %s" % [ + connection.quote_table_name(aliased_join_table_name), + connection.quote_column_name(through_reflection.active_record.inheritance_column), + through_reflection.klass.quote_value(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 = " AND %s.%s = %s" % [ + connection.quote_table_name(aliased_join_table_name), + connection.quote_column_name(reflection.source_reflection.options[:foreign_type]), + klass.quote_value(reflection.options[:source_type]) + ] + else + second_key = source_reflection.primary_key_name + end + end + + " #{join_type} %s ON (%s.%s = %s.%s%s%s%s) " % [ + table_alias_for(through_reflection.klass.table_name, aliased_join_table_name), + connection.quote_table_name(parent.aliased_table_name), + connection.quote_column_name(parent.primary_key), + connection.quote_table_name(aliased_join_table_name), + connection.quote_column_name(jt_foreign_key), + jt_as_extra, jt_source_extra, jt_sti_extra + ] + + " #{join_type} %s ON (%s.%s = %s.%s%s) " % [ + table_name_and_alias, + connection.quote_table_name(aliased_table_name), + connection.quote_column_name(first_key), + connection.quote_table_name(aliased_join_table_name), + connection.quote_column_name(second_key), + as_extra + ] + + when reflection.options[:as] && [:has_many, :has_one].include?(reflection.macro) + " #{join_type} %s ON %s.%s = %s.%s AND %s.%s = %s" % [ + table_name_and_alias, + connection.quote_table_name(aliased_table_name), + "#{reflection.options[:as]}_id", + connection.quote_table_name(parent.aliased_table_name), + parent.primary_key, + connection.quote_table_name(aliased_table_name), + "#{reflection.options[:as]}_type", + klass.quote_value(parent.active_record.base_class.name) + ] + else + foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key + " #{join_type} %s ON %s.%s = %s.%s " % [ + table_name_and_alias, + aliased_table_name, + foreign_key, + parent.aliased_table_name, + parent.primary_key + ] + end + when :belongs_to + " #{join_type} %s ON %s.%s = %s.%s " % [ + table_name_and_alias, + connection.quote_table_name(aliased_table_name), + reflection.klass.primary_key, + connection.quote_table_name(parent.aliased_table_name), + options[:foreign_key] || reflection.primary_key_name + ] + else + "" + end || '' + join << %(AND %s) % [ + klass.send(:type_condition, aliased_table_name)] unless klass.descends_from_active_record? + + [through_reflection, reflection].each do |ref| + join << "AND #{interpolate_sql(sanitize_sql(ref.options[:conditions]))} " if ref && ref.options[:conditions] + end + + join + end + + protected + + def aliased_table_name_for(name, suffix = nil) + if !parent.table_joins.blank? && parent.table_joins.to_s.downcase =~ %r{join(\s+\w+)?\s+#{name.downcase}\son} + @join_dependency.table_aliases[name] += 1 + end + + unless @join_dependency.table_aliases[name].zero? + # if the table name has been used, then use an alias + name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}" + table_index = @join_dependency.table_aliases[name] + @join_dependency.table_aliases[name] += 1 + name = name[0..active_record.connection.table_alias_length-3] + "_#{table_index+1}" if table_index > 0 + 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) + "#{reflection.active_record.connection.quote_table_name(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('@', '\@')}@") + end + + private + def join_type + "LEFT OUTER JOIN" + end + end + end + + class InnerJoinDependency < JoinDependency # :nodoc: + protected + def build_join_association(reflection, parent) + InnerJoinAssociation.new(reflection, self, parent) + end + + class InnerJoinAssociation < JoinAssociation + private + def join_type + "INNER JOIN" + end + end + end + + end + end +end