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require 'active_record/associations/association_proxy'
require 'active_record/associations/association_collection'
require 'active_record/associations/belongs_to_association'
require 'active_record/associations/has_one_association'
require 'active_record/associations/has_many_association'
require 'active_record/associations/has_and_belongs_to_many_association'
require 'active_record/deprecated_associations'
module ActiveRecord
module Associations # :nodoc:
def self.append_features(base)
super
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
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 was 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:
# * <tt>Project#portfolio, Project#portfolio=(portfolio), Project#portfolio.nil?</tt>
# * <tt>Project#project_manager, Project#project_manager=(project_manager), Project#project_manager.nil?,</tt>
# * <tt>Project#milestones.empty?, Project#milestones.size, Project#milestones, Project#milestones<<(milestone),</tt>
# <tt>Project#milestones.delete(milestone), Project#milestones.find(milestone_id), Project#milestones.find_all(conditions),</tt>
# <tt>Project#milestones.build, Project#milestones.create</tt>
# * <tt>Project#categories.empty?, Project#categories.size, Project#categories, Project#categories<<(category1),</tt>
# <tt>Project#categories.delete(category1)</tt>
#
# == Example
#
# link:../../examples/associations.png
#
# == Is it belongs_to or has_one?
#
# Both express a 1-1 relationship, the difference is mostly where to place the foreign key, which goes on the table for the class
# saying belongs_to. Example:
#
# class Post < ActiveRecord::Base
# has_one :author
# end
#
# class Author < ActiveRecord::Base
# belongs_to :post
# end
#
# The tables for these classes could look something like:
#
# CREATE TABLE posts (
# id int(11) NOT NULL auto_increment,
# title varchar default NULL,
# PRIMARY KEY (id)
# )
#
# CREATE TABLE authors (
# id int(11) NOT NULL auto_increment,
# post_id int(11) default NULL,
# 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 behaviour 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.
#
# == 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
#
# == 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 Company < ActiveRecord::Base; end
# end
# end
#
# When Firm#clients is called, it'll in turn call <tt>MyApplication::Business::Company.find(firm.id)</tt>. If you want to associate
# with a class in another module scope this can be done by specifying the complete class name, such as:
#
# 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 <tt>:class_name</tt>, you'll
# get a ActiveRecord::AssociationTypeMismatch.
#
# == Options
#
# All of the association macros can be specialized through options which makes more complex cases than the simple and guessable ones
# possible.
module ClassMethods
# Adds the following methods for retrieval and query of collections of associated objects.
# +collection+ is replaced with the symbol passed as the first argument, so
# <tt>has_many :clients</tt> would add among others <tt>clients.empty?</tt>.
# * <tt>collection(force_reload = false)</tt> - returns an array of all the associated objects.
# An empty array is returned if none are found.
# * <tt>collection<<(object, ...)</tt> - adds one or more objects to the collection by setting their foreign keys to the collection's primary key.
# * <tt>collection.delete(object, ...)</tt> - removes one or more objects from the collection by setting their foreign keys to NULL.
# This will also destroy the objects if they're declared as belongs_to and dependent on this model.
# * <tt>collection.clear</tt> - removes every object from the collection. This does not destroy the objects.
# * <tt>collection.empty?</tt> - returns true if there are no associated objects.
# * <tt>collection.size</tt> - returns the number of associated objects.
# * <tt>collection.find(id)</tt> - finds an associated object responding to the +id+ and that
# meets the condition that it has to be associated with this object.
# * <tt>collection.find_all(conditions = nil, orderings = nil, limit = nil, joins = nil)</tt> - finds all associated objects responding
# criteria mentioned (like in the standard find_all) and that meets the condition that it has to be associated with this object.
# * <tt>collection.build(attributes = {})</tt> - returns a new object of the collection type that has been instantiated
# with +attributes+ and linked to this object through a foreign key but has not yet been saved.
# * <tt>collection.create(attributes = {})</tt> - returns a new object of the collection type that has been instantiated
# with +attributes+ and linked to this object through a foreign key and that has already been saved (if it passed the validation).
#
# Example: A Firm class declares <tt>has_many :clients</tt>, which will add:
# * <tt>Firm#clients</tt> (similar to <tt>Clients.find_all "firm_id = #{id}"</tt>)
# * <tt>Firm#clients<<</tt>
# * <tt>Firm#clients.delete</tt>
# * <tt>Firm#clients.clear</tt>
# * <tt>Firm#clients.empty?</tt> (similar to <tt>firm.clients.size == 0</tt>)
# * <tt>Firm#clients.size</tt> (similar to <tt>Client.count "firm_id = #{id}"</tt>)
# * <tt>Firm#clients.find</tt> (similar to <tt>Client.find_on_conditions(id, "firm_id = #{id}")</tt>)
# * <tt>Firm#clients.find_all</tt> (similar to <tt>Client.find_all "firm_id = #{id}"</tt>)
# * <tt>Firm#clients.build</tt> (similar to <tt>Client.new("firm_id" => id)</tt>)
# * <tt>Firm#clients.create</tt> (similar to <tt>c = Client.new("client_id" => id); c.save; c</tt>)
# The declaration can also include an options hash to specialize the behavior of the association.
#
# Options are:
# * <tt>:class_name</tt> - specify the class name of the association. Use it only if that name can't be inferred
# from the association name. So <tt>has_many :products</tt> will by default be linked to the +Product+ class, but
# if the real class name is +SpecialProduct+, you'll have to specify it with this option.
# * <tt>:conditions</tt> - 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%'".
# * <tt>:order</tt> - specify the order in which the associated objects are returned as a "ORDER BY" sql fragment,
# such as "last_name, first_name DESC"
# * <tt>:foreign_key</tt> - 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.
# * <tt>:dependent</tt> - if set to true all the associated object are destroyed alongside this object.
# May not be set if :exclusively_dependent is also set.
# * <tt>:exclusively_dependent</tt> - if set to true all the associated object are deleted in one SQL statement without having their
# before_destroy callback run. This should only be used on associations that depend solely on this class and don't need to do any
# clean-up in before_destroy. The upside is that it's much faster, especially if there's a counter_cache involved.
# May not be set if :dependent is also set.
# * <tt>:finder_sql</tt> - specify a complete SQL statement to fetch the association. This is a good way to go for complex
# associations that depends on multiple tables. Note: When this option is used, +find_in_collection+ is _not_ added.
# * <tt>:counter_sql</tt> - specify a complete SQL statement to fetch the size of the association. If +:finder_sql+ is
# specified but +:counter_sql+, +:counter_sql+ will be generated by replacing SELECT ... FROM with SELECT COUNT(*) FROM.
#
# Option examples:
# has_many :comments, :order => "posted_on"
# has_many :people, :class_name => "Person", :conditions => "deleted = 0", :order => "name"
# has_many :tracks, :order => "position", :dependent => true
# 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 = {})
validate_options([ :foreign_key, :class_name, :exclusively_dependent, :dependent, :conditions, :order, :finder_sql, :counter_sql ], options.keys)
association_name, association_class_name, association_class_primary_key_name =
associate_identification(association_id, options[:class_name], options[:foreign_key])
require_association_class(association_class_name)
if options[:dependent] and options[:exclusively_dependent]
raise ArgumentError, ':dependent and :exclusively_dependent are mutually exclusive options. You may specify one or the other.' # ' ruby-mode
# See HasManyAssociation#delete_records. Dependent associations
# delete children, otherwise foreign key is set to NULL.
elsif options[:dependent]
module_eval "before_destroy '#{association_name}.each { |o| o.destroy }'"
elsif options[:exclusively_dependent]
module_eval "before_destroy { |record| #{association_class_name}.delete_all(%(#{association_class_primary_key_name} = \#{record.quoted_id})) }"
end
add_multiple_associated_save_callbacks(association_name)
collection_accessor_methods(association_name, association_class_name, association_class_primary_key_name, options, HasManyAssociation)
# deprecated api
deprecated_collection_count_method(association_name)
deprecated_add_association_relation(association_name)
deprecated_remove_association_relation(association_name)
deprecated_has_collection_method(association_name)
deprecated_find_in_collection_method(association_name)
deprecated_find_all_in_collection_method(association_name)
deprecated_collection_create_method(association_name)
deprecated_collection_build_method(association_name)
end
# Adds the following methods for retrieval and query of a single associated object.
# +association+ is replaced with the symbol passed as the first argument, so
# <tt>has_one :manager</tt> would add among others <tt>manager.nil?</tt>.
# * <tt>association(force_reload = false)</tt> - returns the associated object. Nil is returned if none is found.
# * <tt>association=(associate)</tt> - assigns the associate object, extracts the primary key, sets it as the foreign key,
# and saves the associate object.
# * <tt>association.nil?</tt> - returns true if there is no associated object.
# * <tt>association.build(attributes = {})</tt> - 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.
# * <tt>association.create(attributes = {})</tt> - returns a new object of the associated type that has been instantiated
# with +attributes+ and 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 association already exists. It will NOT work if the association is nil.
#
# Example: An Account class declares <tt>has_one :beneficiary</tt>, which will add:
# * <tt>Account#beneficiary</tt> (similar to <tt>Beneficiary.find_first "account_id = #{id}"</tt>)
# * <tt>Account#beneficiary=(beneficiary)</tt> (similar to <tt>beneficiary.account_id = account.id; beneficiary.save</tt>)
# * <tt>Account#beneficiary.nil?</tt>
# * <tt>Account#beneficiary.build</tt> (similar to <tt>Beneficiary.new("account_id" => id)</tt>)
# * <tt>Account#beneficiary.create</tt> (similar to <tt>b = Beneficiary.new("account_id" => id); b.save; b</tt>)
# The declaration can also include an options hash to specialize the behavior of the association.
#
# Options are:
# * <tt>:class_name</tt> - specify the class name of the association. Use it only if that name can't be inferred
# from the association name. So <tt>has_one :manager</tt> 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.
# * <tt>:conditions</tt> - specify the conditions that the associated object must meet in order to be included as a "WHERE"
# sql fragment, such as "rank = 5".
# * <tt>:order</tt> - specify the order from which the associated object will be picked at the top. Specified as
# an "ORDER BY" sql fragment, such as "last_name, first_name DESC"
# * <tt>:dependent</tt> - if set to true, the associated object is destroyed when this object is. It's also destroyed if another
# association is assigned.
# * <tt>:foreign_key</tt> - 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.
#
# Option examples:
# has_one :credit_card, :dependent => true
# has_one :last_comment, :class_name => "Comment", :order => "posted_on"
# has_one :project_manager, :class_name => "Person", :conditions => "role = 'project_manager'"
def has_one(association_id, options = {})
validate_options([ :class_name, :foreign_key, :remote, :conditions, :order, :dependent, :counter_cache ], options.keys)
association_name, association_class_name, association_class_primary_key_name =
associate_identification(association_id, options[:class_name], options[:foreign_key], false)
require_association_class(association_class_name)
module_eval do
after_save <<-EOF
association = instance_variable_get("@#{association_name}")
unless association.nil?
association["#{association_class_primary_key_name}"] = id
association.save(true)
association.send(:construct_sql)
end
EOF
end
association_accessor_methods(association_name, association_class_name, association_class_primary_key_name, options, HasOneAssociation)
module_eval "before_destroy '#{association_name}.destroy unless #{association_name}.nil?'" if options[:dependent]
# deprecated api
deprecated_has_association_method(association_name)
deprecated_build_method("build_", association_name, association_class_name, association_class_primary_key_name)
deprecated_create_method("create_", association_name, association_class_name, association_class_primary_key_name)
deprecated_association_comparison_method(association_name, association_class_name)
end
# Adds the following methods for retrieval and query for a single associated object that this object holds an id to.
# +association+ is replaced with the symbol passed as the first argument, so
# <tt>belongs_to :author</tt> would add among others <tt>author.nil?</tt>.
# * <tt>association(force_reload = false)</tt> - returns the associated object. Nil is returned if none is found.
# * <tt>association=(associate)</tt> - assigns the associate object, extracts the primary key, and sets it as the foreign key.
# * <tt>association.nil?</tt> - returns true if there is no associated object.
# * <tt>association.build(attributes = {})</tt> - 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.
# * <tt>association.create(attributes = {})</tt> - returns a new object of the associated type that has been instantiated
# with +attributes+ and linked to this object through a foreign key and that has already been saved (if it passed the validation).
#
# Example: A Post class declares <tt>belongs_to :author</tt>, which will add:
# * <tt>Post#author</tt> (similar to <tt>Author.find(author_id)</tt>)
# * <tt>Post#author=(author)</tt> (similar to <tt>post.author_id = author.id</tt>)
# * <tt>Post#author?</tt> (similar to <tt>post.author == some_author</tt>)
# * <tt>Post#author.nil?</tt>
# * <tt>Post#author.build</tt> (similar to <tt>Author.new("post_id" => id)</tt>)
# * <tt>Post#author.create</tt> (similar to <tt>b = Author.new("post_id" => id); b.save; b</tt>)
# The declaration can also include an options hash to specialize the behavior of the association.
#
# Options are:
# * <tt>:class_name</tt> - specify the class name of the association. Use it only if that name can't be inferred
# from the association name. So <tt>has_one :author</tt> 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.
# * <tt>:conditions</tt> - specify the conditions that the associated object must meet in order to be included as a "WHERE"
# sql fragment, such as "authorized = 1".
# * <tt>:order</tt> - specify the order from which the associated object will be picked at the top. Specified as
# an "ORDER BY" sql fragment, such as "last_name, first_name DESC"
# * <tt>:foreign_key</tt> - specify the 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 a +Person+ class that makes a belongs_to association to a
# +Boss+ class will use "boss_id" as the default foreign_key.
# * <tt>:counter_cache</tt> - caches the number of belonging objects on the associate class through 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).
#
# 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}'
def belongs_to(association_id, options = {})
validate_options([ :class_name, :foreign_key, :remote, :conditions, :order, :dependent, :counter_cache ], options.keys)
association_name, association_class_name, class_primary_key_name =
associate_identification(association_id, options[:class_name], options[:foreign_key], false)
require_association_class(association_class_name)
association_class_primary_key_name = options[:foreign_key] || Inflector.underscore(Inflector.demodulize(association_class_name)) + "_id"
association_accessor_methods(association_name, association_class_name, association_class_primary_key_name, options, BelongsToAssociation)
module_eval do
before_save <<-EOF
association = instance_variable_get("@#{association_name}")
if not association.nil? and association.new_record?
association.save(true)
self["#{association_class_primary_key_name}"] = association.id
association.send(:construct_sql)
end
EOF
end
if options[:counter_cache]
module_eval(
"after_create '#{association_class_name}.increment_counter(\"#{self.to_s.underscore.pluralize + "_count"}\", #{association_class_primary_key_name})" +
" unless #{association_name}.nil?'"
)
module_eval(
"before_destroy '#{association_class_name}.decrement_counter(\"#{self.to_s.underscore.pluralize + "_count"}\", #{association_class_primary_key_name})" +
" unless #{association_name}.nil?'"
)
end
# deprecated api
deprecated_has_association_method(association_name)
deprecated_association_comparison_method(association_name, association_class_name)
end
# 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".
#
# Any additional fields added to the join table will be placed as attributes when pulling records out through
# has_and_belongs_to_many associations. This is helpful when have information about the association itself
# that you want available on retrieval. Note that any fields in the join table will override matching field names
# in the two joined tables. As a consequence, having an "id" field in the join table usually has the undesirable
# result of clobbering the "id" fields in either of the other two tables.
#
#
# Adds the following methods for retrieval and query.
# +collection+ is replaced with the symbol passed as the first argument, so
# <tt>has_and_belongs_to_many :categories</tt> would add among others <tt>categories.empty?</tt>.
# * <tt>collection(force_reload = false)</tt> - returns an array of all the associated objects.
# An empty array is returned if none is found.
# * <tt>collection<<(object, ...)</tt> - 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).
# * <tt>collection.push_with_attributes(object, join_attributes)</tt> - adds one to the collection by creating an association in the join table that
# also holds the attributes from <tt>join_attributes</tt> (should be a hash with the column names as keys). This can be used to have additional
# attributes on the join, which will be injected into the associated objects when they are retrieved through the collection.
# (collection.concat_with_attributes is an alias to this method).
# * <tt>collection.delete(object, ...)</tt> - removes one or more objects from the collection by removing their associations from the join table.
# This does not destroy the objects.
# * <tt>collection.clear</tt> - removes every object from the collection. This does not destroy the objects.
# * <tt>collection.empty?</tt> - returns true if there are no associated objects.
# * <tt>collection.size</tt> - returns the number of associated objects.
# * <tt>collection.find(id)</tt> - finds an associated object responding to the +id+ and that
# meets the condition that it has to be associated with this object.
#
# Example: An Developer class declares <tt>has_and_belongs_to_many :projects</tt>, which will add:
# * <tt>Developer#projects</tt>
# * <tt>Developer#projects<<</tt>
# * <tt>Developer#projects.push_with_attributes</tt>
# * <tt>Developer#projects.delete</tt>
# * <tt>Developer#projects.clear</tt>
# * <tt>Developer#projects.empty?</tt>
# * <tt>Developer#projects.size</tt>
# * <tt>Developer#projects.find(id)</tt>
# The declaration may include an options hash to specialize the behavior of the association.
#
# Options are:
# * <tt>:class_name</tt> - specify the class name of the association. Use it only if that name can't be inferred
# from the association name. So <tt>has_and_belongs_to_many :projects</tt> 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.
# * <tt>:join_table</tt> - 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.
# * <tt>:foreign_key</tt> - 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.
# * <tt>:association_foreign_key</tt> - 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 the associated class is +Project+
# that makes a has_and_belongs_to_many association will use "project_id" as the default association foreign_key.
# * <tt>:conditions</tt> - specify the conditions that the associated object must meet in order to be included as a "WHERE"
# sql fragment, such as "authorized = 1".
# * <tt>:order</tt> - specify the order in which the associated objects are returned as a "ORDER BY" sql fragment, such as "last_name, first_name DESC"
# * <tt>:uniq</tt> - if set to true, duplicate associated objects will be ignored by accessors and query methods
# * <tt>:finder_sql</tt> - overwrite the default generated SQL used to fetch the association with a manual one
# * <tt>:delete_sql</tt> - overwrite the default generated SQL used to remove links between the associated
# classes with a manual one
# * <tt>:insert_sql</tt> - overwrite the default generated SQL used to add links between the associated classes
# with a manual one
#
# Option examples:
# has_and_belongs_to_many :projects
# has_and_belongs_to_many :nations, :class_name => "Country"
# has_and_belongs_to_many :categories, :join_table => "prods_cats"
def has_and_belongs_to_many(association_id, options = {})
validate_options([ :class_name, :table_name, :foreign_key, :association_foreign_key, :conditions,
:join_table, :finder_sql, :delete_sql, :insert_sql, :order, :uniq ], options.keys)
association_name, association_class_name, association_class_primary_key_name =
associate_identification(association_id, options[:class_name], options[:foreign_key])
require_association_class(association_class_name)
options[:join_table] ||= join_table_name(undecorated_table_name(self.to_s), undecorated_table_name(association_class_name))
add_multiple_associated_save_callbacks(association_name)
collection_accessor_methods(association_name, association_class_name, association_class_primary_key_name, options, HasAndBelongsToManyAssociation)
before_destroy_sql = "DELETE FROM #{options[:join_table]} WHERE #{association_class_primary_key_name} = \\\#{self.quoted_id}"
module_eval(%{before_destroy "self.connection.delete(%{#{before_destroy_sql}})"}) # "
# deprecated api
deprecated_collection_count_method(association_name)
deprecated_add_association_relation(association_name)
deprecated_remove_association_relation(association_name)
deprecated_has_collection_method(association_name)
end
private
# Raises an exception if an invalid option has been specified to prevent misspellings from slipping through
def validate_options(valid_option_keys, supplied_option_keys)
unknown_option_keys = supplied_option_keys - valid_option_keys
raise(ActiveRecord::ActiveRecordError, "Unknown options: #{unknown_option_keys}") unless unknown_option_keys.empty?
end
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 associate_identification(association_id, association_class_name, foreign_key, plural = true)
if association_class_name !~ /::/
association_class_name = type_name_with_module(
association_class_name ||
Inflector.camelize(plural ? Inflector.singularize(association_id.id2name) : association_id.id2name)
)
end
primary_key_name = foreign_key || Inflector.underscore(Inflector.demodulize(name)) + "_id"
return association_id.id2name, association_class_name, primary_key_name
end
def association_accessor_methods(association_name, association_class_name, association_class_primary_key_name, options, association_proxy_class)
define_method(association_name) do |*params|
force_reload = params.first unless params.empty?
association = instance_variable_get("@#{association_name}")
if association.nil? or force_reload
association = association_proxy_class.new(self,
association_name, association_class_name,
association_class_primary_key_name, options)
retval = association.reload
unless retval.nil?
instance_variable_set("@#{association_name}", association)
else
instance_variable_set("@#{association_name}", nil)
return nil
end
end
association
end
define_method("#{association_name}=") do |new_value|
association = instance_variable_get("@#{association_name}")
if association.nil?
association = association_proxy_class.new(self,
association_name, association_class_name,
association_class_primary_key_name, options)
end
association.replace(new_value)
unless new_value.nil?
instance_variable_set("@#{association_name}", association)
else
instance_variable_set("@#{association_name}", nil)
return nil
end
association
end
define_method("set_#{association_name}_target") do |target|
association = association_proxy_class.new(self,
association_name, association_class_name,
association_class_primary_key_name, options)
association.target = target
instance_variable_set("@#{association_name}", association)
end
end
def collection_accessor_methods(association_name, association_class_name, association_class_primary_key_name, options, association_proxy_class)
define_method(association_name) do |*params|
force_reload = params.first unless params.empty?
association = instance_variable_get("@#{association_name}")
unless association.respond_to?(:loaded?)
association = association_proxy_class.new(self,
association_name, association_class_name,
association_class_primary_key_name, options)
instance_variable_set("@#{association_name}", association)
end
association.reload if force_reload
association
end
define_method("#{association_name}=") do |new_value|
association = instance_variable_get("@#{association_name}")
unless association.respond_to?(:loaded?)
association = association_proxy_class.new(self,
association_name, association_class_name,
association_class_primary_key_name, options)
instance_variable_set("@#{association_name}", association)
end
association.replace(new_value)
association
end
end
def require_association_class(class_name)
require_association(Inflector.underscore(class_name)) if class_name
end
def add_multiple_associated_save_callbacks(association_name)
module_eval do
before_save <<-end_eval
@new_record_before_save = new_record?
association = instance_variable_get("@#{association_name}")
if association.respond_to?(:loaded?)
if new_record?
records_to_save = association
else
records_to_save = association.select{ |record| record.new_record? }
end
records_to_save.inject(true) do |result,record|
result &&= record.valid?
end
end
end_eval
end
module_eval do
after_save <<-end_eval
association = instance_variable_get("@#{association_name}")
if association.respond_to?(:loaded?)
if @new_record_before_save
records_to_save = association
else
records_to_save = association.select{ |record| record.new_record? }
end
records_to_save.each{ |record| association.send(:insert_record, record) }
association.send(:construct_sql) # reconstruct the SQL queries now that we know the owner's id
end
end_eval
end
end
def find_with_associations(options = {})
reflections = [ options[:include] ].flatten.collect { |association| reflect_on_association(association) }
rows = connection.select_all(construct_finder_sql_with_included_associations(options, reflections), "#{name} Load Including Associations")
records = rows.collect { |row| instantiate(extract_record(table_name, row)) }.uniq
reflections.each do |reflection|
records.each do |record|
case reflection.macro
when :has_many
record.send(reflection.name).target = extract_association_for_record(record, rows, reflection)
when :has_one, :belongs_to
record.send("set_#{reflection.name}_target", extract_association_for_record(record, rows, reflection).first)
end
end
end
return records
end
def construct_finder_sql_with_included_associations(options, reflections)
sql = "SELECT #{selected_columns(table_name, columns)}"
reflections.each { |reflection| sql << ", #{selected_columns(reflection.klass.table_name, reflection.klass.columns)}" }
sql << " FROM #{table_name} "
reflections.each do |reflection|
case reflection.macro
when :has_many, :has_one
sql << " LEFT JOIN #{reflection.klass.table_name} ON " +
"#{reflection.klass.table_name}.#{table_name.classify.foreign_key} = #{table_name}.#{primary_key} "
when :belongs_to
sql << " LEFT JOIN #{reflection.klass.table_name} ON " +
"#{reflection.klass.table_name}.#{reflection.klass.primary_key} = #{table_name}.#{reflection.klass.table_name.classify.foreign_key} "
end
end
sql << "#{options[:joins]} " if options[:joins]
add_conditions!(sql, options[:conditions])
sql << "ORDER BY #{options[:order]} " if options[:order]
return sanitize_sql(sql)
end
def extract_association_for_record(record, rows, reflection)
association = rows.collect do |row|
if row["#{table_name}__#{primary_key}"] == record.id.to_s && !row["#{reflection.klass.table_name}__#{reflection.klass.primary_key}"].nil?
reflection.klass.send(:instantiate, extract_record(reflection.klass.table_name, row))
end
end
return association.uniq.compact
end
def extract_record(table_name, row)
row.inject({}) do |record, pair|
prefix, column_name = pair.first.split("__")
record[column_name] = pair.last if prefix == table_name
record
end
end
def selected_columns(table_name, columns)
columns.collect { |column| "#{table_name}.#{column.name} as #{table_name}__#{column.name}" }.join(", ")
end
end
end
end
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