Merge branch 'master' of github.com:lifo/docrails

3 files changed, 463 insertions, 34 deletions

diff --git a/activerecord/lib/active_record/aggregations.rb b/activerecord/lib/active_record/aggregations.rb
index f0b549e5ad..3ae7030caa 100644
--- a/activerecord/lib/active_record/aggregations.rb
+++ b/activerecord/lib/active_record/aggregations.rb
@@ -10,9 +10,9 @@ module ActiveRecord
     # Active Record implements aggregation through a macro-like class method called +composed_of+
     # for representing attributes  as value objects. It expresses relationships like "Account [is]
     # composed of Money [among other things]" or "Person [is] composed of [an] address". Each call
-    # to the macro adds a description of how the value objects  are created from the attributes of
-    # the entity object (when the entity is initialized either  as a new object or from finding an
-    # existing object) and how it can be turned back into attributes  (when the entity is saved to
+    # to the macro adds a description of how the value objects are created from the attributes of
+    # the entity object (when the entity is initialized either as a new object or from finding an
+    # existing object) and how it can be turned back into attributes (when the entity is saved to
     # the database).
     #
     #   class Customer < ActiveRecord::Base
diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index fa316a8c9d..100fb38dec 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -37,9 +37,107 @@ module ActiveRecord
       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
+      # If the collection is empty, the first form returns +nil+, and the second
       # form returns an empty array.
       #
       #   class Person < ActiveRecord::Base
@@ -67,8 +165,12 @@ module ActiveRecord
 
       ##
       # :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
+      # If the collection is empty, the first form returns +nil+, and the second
       # form returns an empty array.
       #
       #   class Person < ActiveRecord::Base
@@ -95,7 +197,95 @@ module ActiveRecord
       #   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+
@@ -123,6 +313,10 @@ module ActiveRecord
 
       ##
       # :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.
       #
@@ -147,23 +341,249 @@ module ActiveRecord
       #   # => ActiveRecord::AssociationTypeMismatch: Pet expected, got String
 
       ##
+      # :method: 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
-      # Destroy all the records from this association.
+      #
+      # 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: destroy
+      #
+      # :call-seq:
+      #   destroy(*records)
+      #
+      # Destroy the +records+ supplied and remove 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: 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
+      #
+      # 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.
+      #
+      # Returns +true+ if the collection is empty.
       #
       #   class Person < ActiveRecord::Base
       #     has_many :pets
@@ -179,7 +599,12 @@ module ActiveRecord
 
       ##
       # :method: any?
-      # Returns true if the collection is not empty.
+      #
+      # :call-seq:
+      #   any?
+      #   any?{|item| block}
+      #
+      # Returns +true+ if the collection is not empty.
       #
       #   class Person < ActiveRecord::Base
       #     has_many :pets
@@ -211,8 +636,13 @@ module ActiveRecord
 
       ##
       # :method: many?
+      #
+      # :call-seq:
+      #   many?
+      #   many?{|item| block}
+      #
       # Returns true if the collection has more than one record.
-      # Equivalent to +collection.size > 1+.
+      # Equivalent to <tt>collection.size > 1</tt>.
       #
       #   class Person < ActiveRecord::Base
       #     has_many :pets
@@ -248,7 +678,11 @@ module ActiveRecord
 
       ##
       # :method: include?
-      # Returns true if the given object is present in the collection.
+      #
+      # :call-seq:
+      #   include?(record)
+      #
+      # Returns +true+ if the given object is present in the collection.
       #
       #   class Person < ActiveRecord::Base
       #     has_many :pets
@@ -331,37 +765,32 @@ module ActiveRecord
       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.
+      # 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       # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
-      #   person.pets.clear # => []
-      #   person.pets.size  # => 0
+      #   person.pets # fetches pets from the database
+      #   # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
       #
-      #   Pet.find(1) # => #<Pet id: 1, name: "Snoop", group: "dogs", person_id: nil>
+      #   person.pets # uses the pets cache
+      #   # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
       #
-      # If they are associated with +dependent: :destroy+ option, it deletes
-      # them directly from the database.
+      #   person.pets.reload # fetches pets from the database
+      #   # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
       #
-      #   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
-      end
-
+      #   person.pets(true)  # fetches pets from the database
+      #   # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
       def reload
         proxy_association.reload
         self
diff --git a/activerecord/lib/active_record/associations/preloader.rb b/activerecord/lib/active_record/associations/preloader.rb
index fafed94ff2..54705e4950 100644
--- a/activerecord/lib/active_record/associations/preloader.rb
+++ b/activerecord/lib/active_record/associations/preloader.rb
@@ -12,7 +12,7 @@ module ActiveRecord
     # and all of its books via a single query:
     #
     #   SELECT * FROM authors
-    #   LEFT OUTER JOIN books ON authors.id = books.id
+    #   LEFT OUTER JOIN books ON authors.id = books.author_id
     #   WHERE authors.name = 'Ken Akamatsu'
     #
     # However, this could result in many rows that contain redundant data. After