133c21b801
Update to Rails 2.3.1.
(Actually, not quite. Doesn't look like 2.3.1 will be released
today, but I REALLY want to push these bugfixes out.)
Removed bundled Rack (Rails 2.3.1 comes bundled with Rack 1.0).
Add
config.action_view.cache_template_loading = true
to production environment.
Fix FastCGI bug (http://rubyforge.org/tracker/index.php?func=detail&aid=24191&group_id=186&atid=783).
Fix WikiWords bug (http://rubyforge.org/pipermail/instiki-users/2009-February/001181.html).
2157 lines
111 KiB
Ruby
Executable file
2157 lines
111 KiB
Ruby
Executable file
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(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)} in model #{through_reflection.klass}. Try 'has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}, :source => <name>'. Is it one of #{source_associations.to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)}?")
|
|
end
|
|
end
|
|
|
|
class HasManyThroughSourceAssociationMacroError < ActiveRecordError #:nodoc:
|
|
def initialize(reflection)
|
|
through_reflection = reflection.through_reflection
|
|
source_reflection = reflection.source_reflection
|
|
super("Invalid source reflection macro :#{source_reflection.macro}#{" :through" if source_reflection.options[:through]} for has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}. Use :source to specify the source reflection.")
|
|
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:
|
|
# These classes will be loaded when associatoins are created.
|
|
# So there is no need to eager load them.
|
|
autoload :AssociationCollection, 'active_record/associations/association_collection'
|
|
autoload :AssociationProxy, 'active_record/associations/association_proxy'
|
|
autoload :BelongsToAssociation, 'active_record/associations/belongs_to_association'
|
|
autoload :BelongsToPolymorphicAssociation, 'active_record/associations/belongs_to_polymorphic_association'
|
|
autoload :HasAndBelongsToManyAssociation, 'active_record/associations/has_and_belongs_to_many_association'
|
|
autoload :HasManyAssociation, 'active_record/associations/has_many_association'
|
|
autoload :HasManyThroughAssociation, 'active_record/associations/has_many_through_association'
|
|
autoload :HasOneAssociation, 'active_record/associations/has_one_association'
|
|
autoload :HasOneThroughAssociation, 'active_record/associations/has_one_through_association'
|
|
|
|
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
|
|
|
|
private
|
|
# Gets the specified association instance if it responds to :loaded?, nil otherwise.
|
|
def association_instance_get(name)
|
|
association = instance_variable_get("@#{name}")
|
|
association if association.respond_to?(:loaded?)
|
|
end
|
|
|
|
# Set the specified association instance.
|
|
def association_instance_set(name, association)
|
|
instance_variable_set("@#{name}", association)
|
|
end
|
|
|
|
# Associations are a set of macro-like class methods for tying objects together through foreign keys. They express relationships like
|
|
# "Project has one Project Manager" or "Project belongs to a Portfolio". Each macro adds a number of methods to the class which are
|
|
# specialized according to the collection or association symbol and the options hash. It works much the same way as Ruby's own <tt>attr*</tt>
|
|
# 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, options),</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>
|
|
#
|
|
# === 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
|
|
#
|
|
# ===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.exists? | 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 <tt>:through</tt> 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 <tt>has_many :through</tt>. 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.
|
|
#
|
|
# Unless you enable the :autosave option on a <tt>has_one</tt>, <tt>belongs_to</tt>,
|
|
# <tt>has_many</tt>, or <tt>has_and_belongs_to_many</tt> association,
|
|
# in which case the members are always saved.
|
|
#
|
|
# === One-to-one associations
|
|
#
|
|
# * Assigning an object to a +has_one+ association automatically saves that object and the object being replaced (if there is one), in
|
|
# order to update their primary keys - except if the parent object is unsaved (<tt>new_record? == true</tt>).
|
|
# * If either of these saves fail (due to one of the objects being invalid) the assignment statement returns +false+ and the assignment
|
|
# is cancelled.
|
|
# * If you wish to assign an object to a +has_one+ association without saving it, use the <tt>association.build</tt> method (documented below).
|
|
# * Assigning an object to a +belongs_to+ association does not save the object, since the foreign key field belongs on the parent. It
|
|
# does not save the parent either.
|
|
#
|
|
# === Collections
|
|
#
|
|
# * Adding an object to a collection (+has_many+ or +has_and_belongs_to_many+) automatically saves that object, except if the parent object
|
|
# (the owner of the collection) is not yet stored in the database.
|
|
# * If saving any of the objects being added to a collection (via <tt>push</tt> or similar) fails, then <tt>push</tt> returns +false+.
|
|
# * You can add an object to a collection without automatically saving it by using the <tt>collection.build</tt> method (documented below).
|
|
# * All unsaved (<tt>new_record? == true</tt>) members of the collection are automatically saved when the parent is saved.
|
|
#
|
|
# === 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 <tt>:extend</tt> option.
|
|
# In the case of name conflicts between methods in the modules, methods in modules later in the array supercede
|
|
# those earlier in the array. 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 <tt>:through</tt> option to use an explicit join model to retrieve the data. This
|
|
# operates similarly to a +has_and_belongs_to_many+ association. The advantage is that you're able to add validations,
|
|
# callbacks, and extra attributes on the join model. Consider the following schema:
|
|
#
|
|
# 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 <tt>:author</tt> symbol. After loading the posts, find
|
|
# will collect the +author_id+ from each one and load all the referenced authors with one query. Doing so will cut down the number of queries from 201 to 102.
|
|
#
|
|
# We can improve upon the situation further by referencing both associations in the finder with:
|
|
#
|
|
# for post in Post.find(:all, :include => [ :author, :comments ])
|
|
#
|
|
# This will load all comments with a single query. This reduces the total number of queries to 3. More generally the number of queries
|
|
# will be 1 plus the number of associations 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: <tt>LEFT OUTER JOIN comments ON comments.post_id = posts.id</tt> and
|
|
# <tt>LEFT OUTER JOIN authors ON authors.id = posts.author_id</tt>. Note that using conditions 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
|
|
# <tt>:order => "author.name DESC"</tt> will work but <tt>:order => "name DESC"</tt> will not.
|
|
#
|
|
# If you do want eagerload only some members of an association it is usually more natural to <tt>:include</tt> an association
|
|
# which has conditions defined on it:
|
|
#
|
|
# class Post < ActiveRecord::Base
|
|
# 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 <tt>:limit</tt> 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 <tt>#{reflection_name}_#{parent_table_name}</tt>. 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 <tt>_join</tt> 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 <tt>:joins</tt> 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 <tt>Firm#clients</tt> is called, it will in turn call <tt>MyApplication::Business::Client.find_all_by_firm_id(firm.id)</tt>.
|
|
# If you want to associate with a class in another module scope, this can be done by 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 <tt>ActiveRecord::AssociationTypeMismatch</tt>
|
|
#
|
|
# If you attempt to assign an object to an association that doesn't match the inferred or specified <tt>:class_name</tt>, you'll
|
|
# get an <tt>ActiveRecord::AssociationTypeMismatch</tt>.
|
|
#
|
|
# == Options
|
|
#
|
|
# All of the association macros can be specialized through options. This makes cases 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 <tt>:dependent => :destroy</tt>,
|
|
# and deleted if they're associated with <tt>:dependent => :delete_all</tt>.
|
|
# [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 <tt>:dependent => :destroy</tt>, deletes them directly from the
|
|
# database if <tt>:dependent => :delete_all</tt>, 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.exists?(...)]
|
|
# 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. <b>Note:</b> 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). <b>Note:</b> 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
|
|
# <tt>has_many :clients</tt> would add among others <tt>clients.empty?</tt>.)
|
|
#
|
|
# === Example
|
|
#
|
|
# Example: A Firm class declares <tt>has_many :clients</tt>, which will add:
|
|
# * <tt>Firm#clients</tt> (similar to <tt>Clients.find :all, :conditions => ["firm_id = ?", id]</tt>)
|
|
# * <tt>Firm#clients<<</tt>
|
|
# * <tt>Firm#clients.delete</tt>
|
|
# * <tt>Firm#clients=</tt>
|
|
# * <tt>Firm#client_ids</tt>
|
|
# * <tt>Firm#client_ids=</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(id, :conditions => "firm_id = #{id}")</tt>)
|
|
# * <tt>Firm#clients.exists?(:name => 'ACME')</tt> (similar to <tt>Client.exists?(:name => 'ACME', :firm_id => firm.id)</tt>)
|
|
# * <tt>Firm#clients.build</tt> (similar to <tt>Client.new("firm_id" => id)</tt>)
|
|
# * <tt>Firm#clients.create</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save; c</tt>)
|
|
# 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 <tt>has_many :products</tt> will by default be linked to the Product class, but
|
|
# if the real class name is SpecialProduct, you'll have to specify it with this option.
|
|
# [:conditions]
|
|
# Specify the conditions that the associated objects must meet in order to be included as a +WHERE+
|
|
# SQL fragment, such as <tt>price > 5 AND name LIKE 'B%'</tt>. Record creations from the association are scoped if a hash
|
|
# is used. <tt>has_many :posts, :conditions => {:published => true}</tt> will create published posts with <tt>@blog.posts.create</tt>
|
|
# or <tt>@blog.posts.build</tt>.
|
|
# [:order]
|
|
# Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment,
|
|
# such as <tt>last_name, first_name DESC</tt>.
|
|
# [:foreign_key]
|
|
# Specify the foreign key used for the association. By default this is guessed to be the name
|
|
# of this class in lower-case and "_id" suffixed. So a Person class that makes a +has_many+ association will use "person_id"
|
|
# as the default <tt>:foreign_key</tt>.
|
|
# [:primary_key]
|
|
# Specify the method that returns the primary key used for the association. By default this is +id+.
|
|
# [:dependent]
|
|
# If set to <tt>:destroy</tt> all the associated objects are destroyed
|
|
# alongside this object by calling their +destroy+ method. If set to <tt>:delete_all</tt> all associated
|
|
# objects are deleted *without* calling their +destroy+ method. If set to <tt>:nullify</tt> all associated
|
|
# objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. *Warning:* This option is ignored when also using
|
|
# the <tt>:through</tt> 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 <tt>:finder_sql</tt> is
|
|
# specified but not <tt>:counter_sql</tt>, <tt>:counter_sql</tt> will be generated by replacing <tt>SELECT ... FROM</tt> with <tt>SELECT COUNT(*) FROM</tt>.
|
|
# [:extend]
|
|
# Specify a named module for extending the proxy. See "Association extensions".
|
|
# [: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 <tt>GROUP BY</tt> SQL-clause.
|
|
# [:having]
|
|
# Combined with +:group+ this can be used to filter the records that a <tt>GROUP BY</tt> returns. Uses the <tt>HAVING</tt> SQL-clause.
|
|
# [:limit]
|
|
# An integer determining the limit on the number of rows that should be returned.
|
|
# [:offset]
|
|
# An integer determining the offset from where the rows should be fetched. So at 5, it would skip the first 4 rows.
|
|
# [:select]
|
|
# By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if you, for example, want to do a join
|
|
# but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will raise an error.
|
|
# [:as]
|
|
# Specifies a polymorphic interface (See <tt>belongs_to</tt>).
|
|
# [:through]
|
|
# Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt> and <tt>:foreign_key</tt>
|
|
# are ignored, as the association uses the source reflection. You can only use a <tt>:through</tt> query through a <tt>belongs_to</tt>
|
|
# or <tt>has_many</tt> association on the join model.
|
|
# [:source]
|
|
# Specifies the source association name used by <tt>has_many :through</tt> queries. Only use it if the name cannot be
|
|
# inferred from the association. <tt>has_many :subscribers, :through => :subscriptions</tt> will look for either <tt>:subscribers</tt> or
|
|
# <tt>:subscriber</tt> on Subscription, unless a <tt>:source</tt> is given.
|
|
# [:source_type]
|
|
# Specifies type of the source association used by <tt>has_many :through</tt> queries where the source
|
|
# association is a polymorphic +belongs_to+.
|
|
# [:uniq]
|
|
# If true, duplicates will be omitted from the collection. Useful in conjunction with <tt>:through</tt>.
|
|
# [: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.
|
|
# [:autosave]
|
|
# If true, always save any loaded members and destroy members marked for destruction, when saving the parent object. Off 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_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.
|
|
# [build_association(attributes = {})]
|
|
# Returns a new object of the associated type that has been instantiated
|
|
# with +attributes+ and linked to this object through a foreign key, but has not
|
|
# yet been saved. <b>Note:</b> This ONLY works if an association already exists.
|
|
# It will NOT work if the association is +nil+.
|
|
# [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
|
|
# <tt>has_one :manager</tt> would add among others <tt>manager.nil?</tt>.)
|
|
#
|
|
# === Example
|
|
#
|
|
# An Account class declares <tt>has_one :beneficiary</tt>, which will add:
|
|
# * <tt>Account#beneficiary</tt> (similar to <tt>Beneficiary.find(:first, :conditions => "account_id = #{id}")</tt>)
|
|
# * <tt>Account#beneficiary=(beneficiary)</tt> (similar to <tt>beneficiary.account_id = account.id; beneficiary.save</tt>)
|
|
# * <tt>Account#build_beneficiary</tt> (similar to <tt>Beneficiary.new("account_id" => id)</tt>)
|
|
# * <tt>Account#create_beneficiary</tt> (similar to <tt>b = Beneficiary.new("account_id" => id); b.save; b</tt>)
|
|
#
|
|
# === 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 <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.
|
|
# [:conditions]
|
|
# Specify the conditions that the associated object must meet in order to be included as a +WHERE+
|
|
# SQL fragment, such as <tt>rank = 5</tt>.
|
|
# [:order]
|
|
# Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment,
|
|
# such as <tt>last_name, first_name DESC</tt>.
|
|
# [:dependent]
|
|
# If set to <tt>:destroy</tt>, the associated object is destroyed when this object is. If set to
|
|
# <tt>:delete</tt>, the associated object is deleted *without* calling its destroy method. If set to <tt>:nullify</tt>, the associated
|
|
# object's foreign key is set to +NULL+. 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 <tt>:foreign_key</tt>.
|
|
# [: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 <tt>belongs_to</tt>).
|
|
# [:select]
|
|
# By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, you want to do a join
|
|
# but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will raise an error.
|
|
# [:through]
|
|
# Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt> and <tt>:foreign_key</tt>
|
|
# are ignored, as the association uses the source reflection. You can only use a <tt>:through</tt> query through a
|
|
# <tt>has_one</tt> or <tt>belongs_to</tt> association on the join model.
|
|
# [:source]
|
|
# Specifies the source association name used by <tt>has_one :through</tt> queries. Only use it if the name cannot be
|
|
# inferred from the association. <tt>has_one :favorite, :through => :favorites</tt> will look for a
|
|
# <tt>:favorite</tt> on Favorite, unless a <tt>:source</tt> is given.
|
|
# [:source_type]
|
|
# Specifies type of the source association used by <tt>has_one :through</tt> 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.
|
|
# [:autosave]
|
|
# If true, always save the associated object or destroy it if marked for destruction, when saving the parent object. Off 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)
|
|
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.
|
|
# [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
|
|
# <tt>belongs_to :author</tt> would add among others <tt>author.nil?</tt>.)
|
|
#
|
|
# === 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#build_author</tt> (similar to <tt>post.author = Author.new</tt>)
|
|
# * <tt>Post#create_author</tt> (similar to <tt>post.author = Author.new; post.author.save; post.author</tt>)
|
|
# 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 <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.
|
|
# [:conditions]
|
|
# Specify the conditions that the associated object must meet in order to be included as a +WHERE+
|
|
# SQL fragment, such as <tt>authorized = 1</tt>.
|
|
# [:select]
|
|
# By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, you want to do a join
|
|
# but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will raise an error.
|
|
# [:foreign_key]
|
|
# Specify the foreign key used for the association. By default this is guessed to be the name
|
|
# of the association with an "_id" suffix. So a class that defines a <tt>belongs_to :person</tt> association will use
|
|
# "person_id" as the default <tt>:foreign_key</tt>. Similarly, <tt>belongs_to :favorite_person, :class_name => "Person"</tt>
|
|
# will use a foreign key of "favorite_person_id".
|
|
# [:dependent]
|
|
# If set to <tt>:destroy</tt>, the associated object is destroyed when this object is. If set to
|
|
# <tt>:delete</tt>, the associated object is deleted *without* calling its destroy method. This option should not be specified when
|
|
# <tt>belongs_to</tt> is used in conjunction with a <tt>has_many</tt> relationship on another class because of the potential to leave
|
|
# orphaned records behind.
|
|
# [:counter_cache]
|
|
# Caches the number of belonging objects on the associate class through the use of +increment_counter+
|
|
# and +decrement_counter+. The counter cache is incremented when an object of this class is created and decremented when it's
|
|
# destroyed. This requires that a column named <tt>#{table_name}_count</tt> (such as +comments_count+ for a belonging Comment class)
|
|
# is used on the associate class (such as a Post class). You can also specify a custom counter cache column by providing
|
|
# a column name instead of a +true+/+false+ value to this option (e.g., <tt>:counter_cache => :my_custom_counter</tt>.)
|
|
# Note: Specifying a counter cache will add it to that model's list of readonly attributes 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. <tt>class Post; attr_readonly :comments_count; end</tt>).
|
|
# [: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.
|
|
# [:autosave]
|
|
# If true, always save the associated object or destroy it if marked for destruction, when saving the parent object. Off 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)
|
|
|
|
if reflection.options[:polymorphic]
|
|
association_accessor_methods(reflection, BelongsToPolymorphicAssociation)
|
|
else
|
|
association_accessor_methods(reflection, BelongsToAssociation)
|
|
association_constructor_method(:build, reflection, BelongsToAssociation)
|
|
association_constructor_method(:create, reflection, BelongsToAssociation)
|
|
end
|
|
|
|
# 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
|
|
|
|
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 <tt><</tt> operator for String. This means that if the strings are of different lengths,
|
|
# and the strings are equal when compared up to the shortest length, then the longer string is considered of higher
|
|
# lexical precedence than the shorter one. For example, one would expect the tables "paper_boxes" and "papers"
|
|
# to generate a join table name of "papers_paper_boxes" because of the length of the name "paper_boxes",
|
|
# but it in fact generates a join table name of "paper_boxes_papers". Be aware of this caveat, and use the
|
|
# custom <tt>:join_table</tt> option if you need to.
|
|
#
|
|
# The join table should not have a primary key or a model associated with it. You must manually generate the
|
|
# join table with a migration such as this:
|
|
#
|
|
# class CreateDevelopersProjectsJoinTable < ActiveRecord::Migration
|
|
# def self.up
|
|
# create_table :developers_projects, :id => false do |t|
|
|
# t.integer :developer_id
|
|
# t.integer :project_id
|
|
# end
|
|
# end
|
|
#
|
|
# def self.down
|
|
# drop_table :developers_projects
|
|
# end
|
|
# end
|
|
#
|
|
# Deprecated: Any additional fields added to the join table will be placed as attributes when pulling records out through
|
|
# +has_and_belongs_to_many+ associations. Records returned from join tables with additional attributes will be marked as
|
|
# readonly (because we can't save changes to the additional attributes). It's strongly recommended that you upgrade any
|
|
# associations with attributes to a real join model (see introduction).
|
|
#
|
|
# Adds the following methods for retrieval and query:
|
|
#
|
|
# [collection(force_reload = false)]
|
|
# 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
|
|
# (<tt>collection.push</tt> and <tt>collection.concat</tt> 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.exists?(...)]
|
|
# 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
|
|
# <tt>has_and_belongs_to_many :categories</tt> would add among others <tt>categories.empty?</tt>.)
|
|
#
|
|
# === Example
|
|
#
|
|
# A 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.delete</tt>
|
|
# * <tt>Developer#projects=</tt>
|
|
# * <tt>Developer#project_ids</tt>
|
|
# * <tt>Developer#project_ids=</tt>
|
|
# * <tt>Developer#projects.clear</tt>
|
|
# * <tt>Developer#projects.empty?</tt>
|
|
# * <tt>Developer#projects.size</tt>
|
|
# * <tt>Developer#projects.find(id)</tt>
|
|
# * <tt>Developer#clients.exists?(...)</tt>
|
|
# * <tt>Developer#projects.build</tt> (similar to <tt>Project.new("project_id" => id)</tt>)
|
|
# * <tt>Developer#projects.create</tt> (similar to <tt>c = Project.new("project_id" => id); c.save; c</tt>)
|
|
# 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 <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.
|
|
# [:join_table]
|
|
# Specify the name of the join table if the default based on lexical order isn't what you want.
|
|
# <b>WARNING:</b> 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
|
|
# to Project will use "person_id" as the default <tt>:foreign_key</tt>.
|
|
# [:association_foreign_key]
|
|
# Specify the foreign key used for the association on the receiving side of the association.
|
|
# By default this is guessed to be the name of the associated class in lower-case and "_id" suffixed.
|
|
# So if a Person class makes a +has_and_belongs_to_many+ association to Project,
|
|
# the association will use "project_id" as the default <tt>:association_foreign_key</tt>.
|
|
# [:conditions]
|
|
# Specify the conditions that the associated object must meet in order to be included as a +WHERE+
|
|
# SQL fragment, such as <tt>authorized = 1</tt>. Record creations from the association are scoped if a hash is used.
|
|
# <tt>has_many :posts, :conditions => {:published => true}</tt> will create published posts with <tt>@blog.posts.create</tt>
|
|
# or <tt>@blog.posts.build</tt>.
|
|
# [:order]
|
|
# Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment,
|
|
# such as <tt>last_name, first_name DESC</tt>
|
|
# [: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 <tt>:finder_sql</tt> is
|
|
# specified but not <tt>:counter_sql</tt>, <tt>:counter_sql</tt> will be generated by replacing <tt>SELECT ... FROM</tt> with <tt>SELECT COUNT(*) FROM</tt>.
|
|
# [:delete_sql]
|
|
# Overwrite the default generated SQL statement used to remove links between the associated
|
|
# 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 <tt>GROUP BY</tt> SQL-clause.
|
|
# [:having]
|
|
# Combined with +:group+ this can be used to filter the records that a <tt>GROUP BY</tt> returns. Uses the <tt>HAVING</tt> SQL-clause.
|
|
# [:limit]
|
|
# An integer determining the limit on the number of rows that should be returned.
|
|
# [:offset]
|
|
# An integer determining the offset from where the rows should be fetched. So at 5, it would skip the first 4 rows.
|
|
# [:select]
|
|
# By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, you want to do a join
|
|
# but not include the joined columns. Do not forget to include the primary 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.
|
|
# [:autosave]
|
|
# If true, always save any loaded members and destroy members marked for destruction, when saving the parent object. Off 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)
|
|
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 # alias_method :destroy_without_habtm_shim_for_posts, :destroy_without_callbacks
|
|
def destroy_without_callbacks # def destroy_without_callbacks
|
|
#{reflection.name}.clear # posts.clear
|
|
#{old_method} # destroy_without_habtm_shim_for_posts
|
|
end # 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)
|
|
define_method(reflection.name) do |*params|
|
|
force_reload = params.first unless params.empty?
|
|
association = association_instance_get(reflection.name)
|
|
|
|
if association.nil? || force_reload
|
|
association = association_proxy_class.new(self, reflection)
|
|
retval = association.reload
|
|
if retval.nil? and association_proxy_class == BelongsToAssociation
|
|
association_instance_set(reflection.name, nil)
|
|
return nil
|
|
end
|
|
association_instance_set(reflection.name, association)
|
|
end
|
|
|
|
association.target.nil? ? nil : association
|
|
end
|
|
|
|
define_method("loaded_#{reflection.name}?") do
|
|
association = association_instance_get(reflection.name)
|
|
association && association.loaded?
|
|
end
|
|
|
|
define_method("#{reflection.name}=") do |new_value|
|
|
association = association_instance_get(reflection.name)
|
|
|
|
if association.nil? || association.target != new_value
|
|
association = association_proxy_class.new(self, reflection)
|
|
end
|
|
|
|
if association_proxy_class == HasOneThroughAssociation
|
|
association.create_through_record(new_value)
|
|
self.send(reflection.name, new_value)
|
|
else
|
|
association.replace(new_value)
|
|
association_instance_set(reflection.name, 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
|
|
association_instance_set(reflection.name, association)
|
|
end
|
|
end
|
|
|
|
def collection_reader_method(reflection, association_proxy_class)
|
|
define_method(reflection.name) do |*params|
|
|
force_reload = params.first unless params.empty?
|
|
association = association_instance_get(reflection.name)
|
|
|
|
unless association
|
|
association = association_proxy_class.new(self, reflection)
|
|
association_instance_set(reflection.name, association)
|
|
end
|
|
|
|
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 association_constructor_method(constructor, reflection, association_proxy_class)
|
|
define_method("#{constructor}_#{reflection.name}") do |*params|
|
|
attributees = params.first unless params.empty?
|
|
replace_existing = params[1].nil? ? true : params[1]
|
|
association = association_instance_get(reflection.name)
|
|
|
|
unless association
|
|
association = association_proxy_class.new(self, reflection)
|
|
association_instance_set(reflection.name, association)
|
|
end
|
|
|
|
if association_proxy_class == HasOneAssociation
|
|
association.send(constructor, attributees, replace_existing)
|
|
else
|
|
association.send(constructor, attributees)
|
|
end
|
|
end
|
|
end
|
|
|
|
def 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 ")
|
|
dependent_conditions = dependent_conditions.gsub('@', '\@')
|
|
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| # before_destroy do |record|
|
|
delete_all_has_many_dependencies(record, # delete_all_has_many_dependencies(record,
|
|
"#{reflection.name}", # "posts",
|
|
#{reflection.class_name}, # Post,
|
|
%@#{dependent_conditions}@) # %@...@) # this is a string literal like %(...)
|
|
end # end
|
|
}
|
|
when :nullify
|
|
module_eval %Q{
|
|
before_destroy do |record| # before_destroy do |record|
|
|
nullify_has_many_dependencies(record, # nullify_has_many_dependencies(record,
|
|
"#{reflection.name}", # "posts",
|
|
#{reflection.class_name}, # Post,
|
|
"#{reflection.primary_key_name}", # "user_id",
|
|
%@#{dependent_conditions}@) # %@...@) # this is a string literal like %(...)
|
|
end # 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
|
|
after_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
|
|
after_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, :having, :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, :having, :limit, :offset,
|
|
:uniq,
|
|
:finder_sql, :counter_sql, :delete_sql, :insert_sql,
|
|
:before_add, :after_add, :before_remove, :after_remove,
|
|
:extend, :readonly,
|
|
:validate
|
|
]
|
|
|
|
def create_has_and_belongs_to_many_reflection(association_id, options, &extension)
|
|
options.assert_valid_keys(valid_keys_for_has_and_belongs_to_many_association)
|
|
|
|
options[:extend] = create_extension_modules(association_id, extension, options[:extend])
|
|
|
|
reflection = create_reflection(:has_and_belongs_to_many, association_id, options, self)
|
|
|
|
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], options[:having], 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], options[:having], 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 tables_in_string(string)
|
|
return [] if string.blank?
|
|
string.scan(/([\.a-zA-Z_]+).?\./).flatten
|
|
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
|
|
when Hash then all << cond.keys
|
|
else all << cond
|
|
end
|
|
end
|
|
tables_in_string(conditions.join(' '))
|
|
end
|
|
|
|
def order_tables(options)
|
|
order = [options[:order], scope(:find, :order) ].join(", ")
|
|
return [] unless order && order.is_a?(String)
|
|
tables_in_string(order)
|
|
end
|
|
|
|
def selects_tables(options)
|
|
select = options[:select]
|
|
return [] unless select && select.is_a?(String)
|
|
tables_in_string(select)
|
|
end
|
|
|
|
def joined_tables(options)
|
|
scope = scope(:find)
|
|
joins = options[:joins]
|
|
merged_joins = scope && scope[:joins] && joins ? merge_joins(scope[:joins], joins) : (joins || scope && scope[:joins])
|
|
[table_name] + case merged_joins
|
|
when Symbol, Hash, Array
|
|
if array_of_strings?(merged_joins)
|
|
tables_in_string(merged_joins.join(' '))
|
|
else
|
|
join_dependency = ActiveRecord::Associations::ClassMethods::InnerJoinDependency.new(self, merged_joins, nil)
|
|
join_dependency.join_associations.collect {|join_association| [join_association.aliased_join_table_name, join_association.aliased_table_name]}.flatten.compact
|
|
end
|
|
else
|
|
tables_in_string(merged_joins)
|
|
end
|
|
end
|
|
|
|
# Checks if the conditions reference a table other than the current model table
|
|
def include_eager_conditions?(options, tables = nil, joined_tables = nil)
|
|
((tables || conditions_tables(options)) - (joined_tables || joined_tables(options))).any?
|
|
end
|
|
|
|
# Checks if the query order references a table other than the current model's table.
|
|
def include_eager_order?(options, tables = nil, joined_tables = nil)
|
|
((tables || order_tables(options)) - (joined_tables || joined_tables(options))).any?
|
|
end
|
|
|
|
def include_eager_select?(options, joined_tables = nil)
|
|
(selects_tables(options) - (joined_tables || joined_tables(options))).any?
|
|
end
|
|
|
|
def references_eager_loaded_tables?(options)
|
|
joined_tables = joined_tables(options)
|
|
include_eager_order?(options, nil, joined_tables) || include_eager_conditions?(options, nil, joined_tables) || include_eager_select?(options, joined_tables)
|
|
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,
|
|
reflection.options[:primary_key] || 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+#{active_record.connection.quote_table_name 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
|