diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/collection_proxy.rb')
| -rw-r--r-- | activerecord/lib/active_record/associations/collection_proxy.rb | 325 |
1 files changed, 285 insertions, 40 deletions
diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb index 3181ca9a32..fa316a8c9d 100644 --- a/activerecord/lib/active_record/associations/collection_proxy.rb +++ b/activerecord/lib/active_record/associations/collection_proxy.rb @@ -33,17 +33,231 @@ module ActiveRecord # # is computed directly through SQL and does not trigger by itself the # instantiation of the actual post records. - class CollectionProxy # :nodoc: - alias :proxy_extend :extend + class CollectionProxy < Relation + delegate :target, :load_target, :loaded?, :to => :@association - instance_methods.each { |m| undef_method m unless m.to_s =~ /^(?:nil\?|send|object_id|to_a)$|^__|^respond_to|proxy_/ } + ## + # :method: first + # 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) # => [] - delegate :group, :order, :limit, :joins, :where, :preload, :eager_load, :includes, :from, - :lock, :readonly, :having, :to => :scoped + ## + # :method: last + # 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) # => [] - delegate :target, :load_target, :loaded?, :scoped, - :to => :@association + ## + # :method: concat + # 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 + # 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: destroy_all + # Destroy all the records from this association. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets.size # => 3 + # + # person.pets.destroy_all + # + # person.pets.size # => 0 + # person.pets # => [] + + ## + # :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? + # 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? + # Returns true if the collection has more than one record. + # Equivalent to +collection.size > 1+. + # + # 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? + # 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, @@ -53,7 +267,8 @@ module ActiveRecord def initialize(association) @association = association - Array.wrap(association.options[:extend]).each { |ext| proxy_extend(ext) } + super association.klass, association.klass.arel_table + merge! association.scoped end alias_method :new, :build @@ -62,44 +277,28 @@ module ActiveRecord @association end - def respond_to?(name, include_private = false) - super || - (load_target && target.respond_to?(name, include_private)) || - proxy_association.klass.respond_to?(name, include_private) + # We don't want this object to be put on the scoping stack, because + # that could create an infinite loop where we call an @association + # method, which gets the current scope, which is this object, which + # delegates to @association, and so on. + def scoping + @association.scoped.scoping { yield } end - def method_missing(method, *args, &block) - match = DynamicFinderMatch.match(method) - if match && match.instantiator? - send(:find_or_instantiator_by_attributes, match, match.attribute_names, *args) do |r| - proxy_association.send :set_owner_attributes, r - proxy_association.send :add_to_target, r - yield(r) if block_given? - end - end + def spawn + scoped + end + + def scoped(options = nil) + association = @association - if target.respond_to?(method) || (!proxy_association.klass.respond_to?(method) && Class.respond_to?(method)) - if load_target - if target.respond_to?(method) - target.send(method, *args, &block) - else - begin - super - rescue NoMethodError => e - raise e, e.message.sub(/ for #<.*$/, " via proxy for #{target}") - end - end - end - - else - scoped.readonly(nil).send(method, *args, &block) + super.extending! do + define_method(:proxy_association) { association } end end - # Forwards <tt>===</tt> explicitly to the \target because the instance method - # removal above doesn't catch it. Loads the \target if needed. - def ===(other) - other === load_target + def ==(other) + load_target == other end def to_ary @@ -107,11 +306,57 @@ module ActiveRecord 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, :<< + # Removes every object from the collection. This does not destroy + # the objects, it sets their foreign keys to +NULL+. Returns +self+ + # so methods can be chained. + # + # class Person < ActiveRecord::Base + # has_many :pets + # end + # + # person.pets # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>] + # person.pets.clear # => [] + # person.pets.size # => 0 + # + # Pet.find(1) # => #<Pet id: 1, name: "Snoop", group: "dogs", person_id: nil> + # + # If they are associated with +dependent: :destroy+ option, it deletes + # them directly from the database. + # + # class Person < ActiveRecord::Base + # has_many :pets, dependent: :destroy + # end + # + # person.pets # => [#<Pet id: 2, name: "Gorby", group: "cats", person_id: 2>] + # person.pets.clear # => [] + # person.pets.size # => 0 + # + # Pet.find(2) # => ActiveRecord::RecordNotFound: Couldn't find Pet with id=2 def clear delete_all self |