diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/collection_proxy.rb')
| -rw-r--r-- | activerecord/lib/active_record/associations/collection_proxy.rb | 934 |
1 files changed, 932 insertions, 2 deletions
diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb index cf4cc98f38..2176fc4e40 100644 --- a/activerecord/lib/active_record/associations/collection_proxy.rb +++ b/activerecord/lib/active_record/associations/collection_proxy.rb @@ -33,9 +33,841 @@ module ActiveRecord # # is computed directly through SQL and does not trigger by itself the # instantiation of the actual post records. - class CollectionProxy < Relation # :nodoc: + class CollectionProxy < Relation delegate :target, :load_target, :loaded?, :to => :@association + ## + # :method: select + # + # :call-seq: + # select(select = nil) + # select(&block) + # + # Works in two ways. + # + # *First:* Specify a subset of fields to be selected from the result set. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.select(:name) + # # => [ + # # #<Pet id: nil, name: "Fancy-Fancy">, + # # #<Pet id: nil, name: "Spook">, + # # #<Pet id: nil, name: "Choo-Choo"> + # # ] + # + # person.pets.select([:id, :name]) + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy">, + # # #<Pet id: 2, name: "Spook">, + # # #<Pet id: 3, name: "Choo-Choo"> + # # ] + # + # Be careful because this also means you’re initializing a model + # object with only the fields that you’ve selected. If you attempt + # to access a field that is not in the initialized record you’ll + # receive: + # + # person.pets.select(:name).first.person_id + # # => ActiveModel::MissingAttributeError: missing attribute: person_id + # + # *Second:* You can pass a block so it can be used just like Array#select. + # This build an array of objects from the database for the scope, + # converting them into an array and iterating through them using + # Array#select. + # + # person.pets.select { |pet| pet.name =~ /oo/ } + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.select(:name) { |pet| pet.name =~ /oo/ } + # # => [ + # # #<Pet id: 2, name: "Spook">, + # # #<Pet id: 3, name: "Choo-Choo"> + # # ] + + ## + # :method: find + # + # :call-seq: + # find(*args, &block) + # + # Finds an object in the collection responding to the +id+. Uses the same + # rules as +ActiveRecord::Base.find+. Returns +ActiveRecord::RecordNotFound++ + # error if the object can not be found. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.find(1) # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1> + # person.pets.find(4) # => ActiveRecord::RecordNotFound: Couldn't find Pet with id=4 + # + # person.pets.find(2) { |pet| pet.name.downcase! } + # # => #<Pet id: 2, name: "fancy-fancy", person_id: 1> + # + # person.pets.find(2, 3) + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + + ## + # :method: first + # + # :call-seq: + # first(limit = nil) + # + # Returns the first record, or the first +n+ records, from the collection. + # If the collection is empty, the first form returns +nil+, and the second + # form returns an empty array. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.first # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1> + # + # person.pets.first(2) + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1> + # # ] + # + # another_person_without.pets # => [] + # another_person_without.pets.first # => nil + # another_person_without.pets.first(3) # => [] + + ## + # :method: last + # + # :call-seq: + # last(limit = nil) + # + # Returns the last record, or the last +n+ records, from the collection. + # If the collection is empty, the first form returns +nil+, and the second + # form returns an empty array. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.last # => #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # + # person.pets.last(2) + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # another_person_without.pets # => [] + # another_person_without.pets.last # => nil + # another_person_without.pets.last(3) # => [] + + ## + # :method: build + # + # :call-seq: + # build(attributes = {}, options = {}, &block) + # + # Returns a new object of the collection type that has been instantiated + # with +attributes+ and linked to this object, but have not yet been saved. + # You can pass an array of attributes hashes, this will return an array + # with the new objects. + # + # class Person + # has_many :pets + # end + # + # person.pets.build + # # => #<Pet id: nil, name: nil, person_id: 1> + # + # person.pets.build(name: 'Fancy-Fancy') + # # => #<Pet id: nil, name: "Fancy-Fancy", person_id: 1> + # + # person.pets.build([{name: 'Spook'}, {name: 'Choo-Choo'}, {name: 'Brain'}]) + # # => [ + # # #<Pet id: nil, name: "Spook", person_id: 1>, + # # #<Pet id: nil, name: "Choo-Choo", person_id: 1>, + # # #<Pet id: nil, name: "Brain", person_id: 1> + # # ] + # + # person.pets.size # => 5 # size of the collection + # person.pets.count # => 0 # count from database + + ## + # :method: create + # + # :call-seq: + # create(attributes = {}, options = {}, &block) + # + # Returns a new object of the collection type that has been instantiated with + # attributes, linked to this object and that has already been saved (if it + # passes the validations). + # + # class Person + # has_many :pets + # end + # + # person.pets.create(name: 'Fancy-Fancy') + # # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1> + # + # person.pets.create([{name: 'Spook'}, {name: 'Choo-Choo'}]) + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.size # => 3 + # person.pets.count # => 3 + # + # person.pets.find(1, 2, 3) + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + + ## + # :method: create! + # + # :call-seq: + # create!(attributes = {}, options = {}, &block) + # + # Like +create+, except that if the record is invalid, raises an exception. + # + # class Person + # has_many :pets + # end + # + # class Pet + # attr_accessible :name + # validates :name, presence: true + # end + # + # person.pets.create!(name: nil) + # # => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank + + ## + # :method: concat + # + # :call-seq: + # concat(*records) + # + # Add one or more records to the collection by setting their foreign keys + # to the association's primary key. Since << flattens its argument list and + # inserts each record, +push+ and +concat+ behave identically. Returns +self+ + # so method calls may be chained. + # + # class Person < ActiveRecord::Base + # pets :has_many + # end + # + # person.pets.size # => 0 + # person.pets.concat(Pet.new(name: 'Fancy-Fancy')) + # person.pets.concat(Pet.new(name: 'Spook'), Pet.new(name: 'Choo-Choo')) + # person.pets.size # => 3 + # + # person.id # => 1 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.concat([Pet.new(name: 'Brain'), Pet.new(name: 'Benny')]) + # person.pets.size # => 5 + + ## + # :method: replace + # + # :call-seq: + # replace(other_array) + # + # Replace this collection with +other_array+. This will perform a diff + # and delete/add only records that have changed. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets + # # => [#<Pet id: 1, name: "Gorby", group: "cats", person_id: 1>] + # + # other_pets = [Pet.new(name: 'Puff', group: 'celebrities'] + # + # person.pets.replace(other_pets) + # + # person.pets + # # => [#<Pet id: 2, name: "Puff", group: "celebrities", person_id: 1>] + # + # If the supplied array has an incorrect association type, it raises + # an <tt>ActiveRecord::AssociationTypeMismatch</tt> error: + # + # person.pets.replace(["doo", "ggie", "gaga"]) + # # => ActiveRecord::AssociationTypeMismatch: Pet expected, got String + + ## + # :method: delete_all + # + # :call-seq: + # delete_all() + # + # Deletes all the records from the collection. For +has_many+ asssociations, + # the deletion is done according to the strategy specified by the <tt>:dependent</tt> + # option. Returns an array with the deleted records. + # + # If no <tt>:dependent</tt> option is given, then it will follow the + # default strategy. The default strategy is <tt>:nullify</tt>. This + # sets the foreign keys to <tt>NULL</tt>. For, +has_many+ <tt>:through</tt>, + # the default strategy is +delete_all+. + # + # class Person < ActiveRecord::Base + # has_many :pets # dependent: :nullify option by default + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.delete_all + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.size # => 0 + # person.pets # => [] + # + # Pet.find(1, 2, 3) + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: nil>, + # # #<Pet id: 2, name: "Spook", person_id: nil>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: nil> + # # ] + # + # If it is set to <tt>:destroy</tt> all the objects from the collection + # are removed by calling their +destroy+ method. See +destroy+ for more + # information. + # + # class Person < ActiveRecord::Base + # has_many :pets, dependent: :destroy + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.delete_all + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # Pet.find(1, 2, 3) + # # => ActiveRecord::RecordNotFound + # + # If it is set to <tt>:delete_all</tt>, all the objects are deleted + # *without* calling their +destroy+ method. + # + # class Person < ActiveRecord::Base + # has_many :pets, dependent: :delete_all + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.delete_all + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # Pet.find(1, 2, 3) + # # => ActiveRecord::RecordNotFound + + ## + # :method: destroy_all + # + # :call-seq: + # destroy_all() + # + # Deletes the records of the collection directly from the database. + # This will _always_ remove the records ignoring the +:dependent+ + # option. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.destroy_all + # + # person.pets.size # => 0 + # person.pets # => [] + # + # Pet.find(1) # => Couldn't find Pet with id=1 + + ## + # :method: delete + # + # :call-seq: + # delete(*records) + # delete(*fixnum_ids) + # delete(*string_ids) + # + # Deletes the +records+ supplied and removes them from the collection. For + # +has_many+ associations, the deletion is done according to the strategy + # specified by the <tt>:dependent</tt> option. Returns an array with the + # deleted records. + # + # If no <tt>:dependent</tt> option is given, then it will follow the default + # strategy. The default strategy is <tt>:nullify</tt>. This sets the foreign + # keys to <tt>NULL</tt>. For, +has_many+ <tt>:through</tt>, the default + # strategy is +delete_all+. + # + # class Person < ActiveRecord::Base + # has_many :pets # dependent: :nullify option by default + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.delete(Pet.find(1)) + # # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>] + # + # person.pets.size # => 2 + # person.pets + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # Pet.find(1) + # # => #<Pet id: 1, name: "Fancy-Fancy", person_id: nil> + # + # If it is set to <tt>:destroy</tt> all the +records+ are removed by calling + # their +destroy+ method. See +destroy+ for more information. + # + # class Person < ActiveRecord::Base + # has_many :pets, dependent: :destroy + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.delete([Pet.find(1), Pet.find(3)]) + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.size # => 1 + # person.pets + # # => [#<Pet id: 2, name: "Spook", person_id: 1>] + # + # Pet.find(1, 3) + # # => ActiveRecord::RecordNotFound: Couldn't find all Pets with IDs (1, 3) + # + # If it is set to <tt>:delete_all</tt>, all the +records+ are deleted + # *without* calling their +destroy+ method. + # + # class Person < ActiveRecord::Base + # has_many :pets, dependent: :delete_all + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.delete(Pet.find(1)) + # # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>] + # + # person.pets.size # => 2 + # person.pets + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # Pet.find(1) + # # => ActiveRecord::RecordNotFound: Couldn't find Pet with id=1 + # + # You can pass +Fixnum+ or +String+ values, it finds the records + # responding to the +id+ and executes delete on them. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.delete("1") + # # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>] + # + # person.pets.delete(2, 3) + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + + ## + # :method: destroy + # + # :call-seq: + # destroy(*records) + # + # Destroys the +records+ supplied and removes them from the collection. + # This method will _always_ remove record from the database ignoring + # the +:dependent+ option. Returns an array with the removed records. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.destroy(Pet.find(1)) + # # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>] + # + # person.pets.size # => 2 + # person.pets + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.destroy(Pet.find(2), Pet.find(3)) + # # => [ + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.size # => 0 + # person.pets # => [] + # + # Pet.find(1, 2, 3) # => ActiveRecord::RecordNotFound: Couldn't find all Pets with IDs (1, 2, 3) + # + # You can pass +Fixnum+ or +String+ values, it finds the records + # responding to the +id+ and then deletes them from the database. + # + # person.pets.size # => 3 + # person.pets + # # => [ + # # #<Pet id: 4, name: "Benny", person_id: 1>, + # # #<Pet id: 5, name: "Brain", person_id: 1>, + # # #<Pet id: 6, name: "Boss", person_id: 1> + # # ] + # + # person.pets.destroy("4") + # # => #<Pet id: 4, name: "Benny", person_id: 1> + # + # person.pets.size # => 2 + # person.pets + # # => [ + # # #<Pet id: 5, name: "Brain", person_id: 1>, + # # #<Pet id: 6, name: "Boss", person_id: 1> + # # ] + # + # person.pets.destroy(5, 6) + # # => [ + # # #<Pet id: 5, name: "Brain", person_id: 1>, + # # #<Pet id: 6, name: "Boss", person_id: 1> + # # ] + # + # person.pets.size # => 0 + # person.pets # => [] + # + # Pet.find(4, 5, 6) # => ActiveRecord::RecordNotFound: Couldn't find all Pets with IDs (4, 5, 6) + + ## + # :method: uniq + # + # :call-seq: + # uniq() + # + # Specifies whether the records should be unique or not. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.select(:name) + # # => [ + # # #<Pet name: "Fancy-Fancy">, + # # #<Pet name: "Fancy-Fancy"> + # # ] + # + # person.pets.select(:name).uniq + # # => [#<Pet name: "Fancy-Fancy">] + + ## + # :method: count + # + # :call-seq: + # count() + # + # Count all records using SQL. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.count # => 3 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + + ## + # :method: size + # + # :call-seq: + # size() + # + # Returns the size of the collection. If the collection hasn't been loaded, + # it executes a <tt>SELECT COUNT(*)</tt> query. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.size # => 3 + # # executes something like SELECT COUNT(*) FROM "pets" WHERE "pets"."person_id" = 1 + # + # person.pets # This will execute a SELECT * FROM query + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + # + # person.pets.size # => 3 + # # Because the collection is already loaded, this will behave like + # # collection.size and no SQL count query is executed. + + ## + # :method: length + # + # :call-seq: + # length() + # + # Returns the size of the collection calling +size+ on the target. + # If the collection has been already loaded, +length+ and +size+ are + # equivalent. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.length # => 3 + # # executes something like SELECT "pets".* FROM "pets" WHERE "pets"."person_id" = 1 + # + # # Because the collection is loaded, you can + # # call the collection with no additional queries: + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] + + ## + # :method: empty? + # + # Returns +true+ if the collection is empty. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.count # => 1 + # person.pets.empty? # => false + # + # person.pets.delete_all + # + # person.pets.count # => 0 + # person.pets.empty? # => true + + ## + # :method: any? + # + # :call-seq: + # any? + # any?{|item| block} + # + # Returns +true+ if the collection is not empty. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.count # => 0 + # person.pets.any? # => false + # + # person.pets << Pet.new(name: 'Snoop') + # person.pets.count # => 0 + # person.pets.any? # => true + # + # You can also pass a block to define criteria. The behaviour + # is the same, it returns true if the collection based on the + # criteria is not empty. + # + # person.pets + # # => [#<Pet name: "Snoop", group: "dogs">] + # + # person.pets.any? do |pet| + # pet.group == 'cats' + # end + # # => false + # + # person.pets.any? do |pet| + # pet.group == 'dogs' + # end + # # => true + + ## + # :method: many? + # + # :call-seq: + # many? + # many?{|item| block} + # + # Returns true if the collection has more than one record. + # Equivalent to <tt>collection.size > 1</tt>. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.count #=> 1 + # person.pets.many? #=> false + # + # person.pets << Pet.new(name: 'Snoopy') + # person.pets.count #=> 2 + # person.pets.many? #=> true + # + # You can also pass a block to define criteria. The + # behaviour is the same, it returns true if the collection + # based on the criteria has more than one record. + # + # person.pets + # # => [ + # # #<Pet name: "Gorby", group: "cats">, + # # #<Pet name: "Puff", group: "cats">, + # # #<Pet name: "Snoop", group: "dogs"> + # # ] + # + # person.pets.many? do |pet| + # pet.group == 'dogs' + # end + # # => false + # + # person.pets.many? do |pet| + # pet.group == 'cats' + # end + # # => true + + ## + # :method: include? + # + # :call-seq: + # include?(record) + # + # Returns +true+ if the given object is present in the collection. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets # => [#<Pet id: 20, name: "Snoop">] + # + # person.pets.include?(Pet.find(20)) # => true + # person.pets.include?(Pet.find(21)) # => false delegate :select, :find, :first, :last, :build, :create, :create!, :concat, :replace, :delete_all, :destroy_all, :delete, :destroy, :uniq, @@ -43,7 +875,7 @@ module ActiveRecord :any?, :many?, :include?, :to => :@association - def initialize(association) + def initialize(association) #:nodoc: @association = association super association.klass, association.klass.arel_table merge! association.scoped @@ -75,25 +907,123 @@ module ActiveRecord end end + # Equivalent to <tt>Array#==</tt>. Returns +true+ if the two arrays + # contain the same number of elements and if each element is equal + # to the corresponding element in the other array, otherwise returns + # +false+. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1> + # # ] + # + # other = person.pets.to_ary + # + # person.pets == other + # # => true + # + # other = [Pet.new(id: 1), Pet.new(id: 2)] + # + # person.pets == other + # # => false def ==(other) load_target == other end + # Returns a new array of objects from the collection. If the collection + # hasn't been loaded, it fetches the records from the database. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets + # # => [ + # # #<Pet id: 4, name: "Benny", person_id: 1>, + # # #<Pet id: 5, name: "Brain", person_id: 1>, + # # #<Pet id: 6, name: "Boss", person_id: 1> + # # ] + # + # other_pets = person.pets.to_ary + # # => [ + # # #<Pet id: 4, name: "Benny", person_id: 1>, + # # #<Pet id: 5, name: "Brain", person_id: 1>, + # # #<Pet id: 6, name: "Boss", person_id: 1> + # # ] + # + # other_pets.replace([Pet.new(name: 'BooGoo')]) + # + # other_pets + # # => [#<Pet id: nil, name: "BooGoo", person_id: 1>] + # + # person.pets + # # This is not affected by replace + # # => [ + # # #<Pet id: 4, name: "Benny", person_id: 1>, + # # #<Pet id: 5, name: "Brain", person_id: 1>, + # # #<Pet id: 6, name: "Boss", person_id: 1> + # # ] def to_ary load_target.dup end alias_method :to_a, :to_ary + # Adds one or more +records+ to the collection by setting their foreign keys + # to the association‘s primary key. Returns +self+, so several appends may be + # chained together. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.size # => 0 + # person.pets << Pet.new(name: 'Fancy-Fancy') + # person.pets << [Pet.new(name: 'Spook'), Pet.new(name: 'Choo-Choo')] + # person.pets.size # => 3 + # + # person.id # => 1 + # person.pets + # # => [ + # # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, + # # #<Pet id: 2, name: "Spook", person_id: 1>, + # # #<Pet id: 3, name: "Choo-Choo", person_id: 1> + # # ] def <<(*records) proxy_association.concat(records) && self end alias_method :push, :<< + # Equivalent to +delete_all+. The difference is that returns +self+, instead + # of an array with the deleted objects, so methods can be chained. See + # +delete_all+ for more information. def clear delete_all self end + # Reloads the collection from the database. Returns +self+. + # Equivalent to <tt>collection(true)</tt>. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets # fetches pets from the database + # # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>] + # + # person.pets # uses the pets cache + # # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>] + # + # person.pets.reload # fetches pets from the database + # # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>] + # + # person.pets(true) # fetches pets from the database + # # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>] def reload proxy_association.reload self |