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tag: v3.1.5
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require 'active_support/core_ext/hash/except'
require 'active_support/core_ext/object/try'
require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/hash/indifferent_access'
require 'active_support/core_ext/class/attribute'
module ActiveRecord
module NestedAttributes #:nodoc:
class TooManyRecords < ActiveRecordError
end
extend ActiveSupport::Concern
included do
class_attribute :nested_attributes_options, :instance_writer => false
self.nested_attributes_options = {}
end
# = Active Record Nested Attributes
#
# Nested attributes allow you to save attributes on associated records
# through the parent. By default nested attribute updating is turned off,
# you can enable it using the accepts_nested_attributes_for class method.
# When you enable nested attributes an attribute writer is defined on
# the model.
#
# The attribute writer is named after the association, which means that
# in the following example, two new methods are added to your model:
#
# <tt>author_attributes=(attributes)</tt> and
# <tt>pages_attributes=(attributes)</tt>.
#
# class Book < ActiveRecord::Base
# has_one :author
# has_many :pages
#
# accepts_nested_attributes_for :author, :pages
# end
#
# Note that the <tt>:autosave</tt> option is automatically enabled on every
# association that accepts_nested_attributes_for is used for.
#
# === One-to-one
#
# Consider a Member model that has one Avatar:
#
# class Member < ActiveRecord::Base
# has_one :avatar
# accepts_nested_attributes_for :avatar
# end
#
# Enabling nested attributes on a one-to-one association allows you to
# create the member and avatar in one go:
#
# params = { :member => { :name => 'Jack', :avatar_attributes => { :icon => 'smiling' } } }
# member = Member.create(params[:member])
# member.avatar.id # => 2
# member.avatar.icon # => 'smiling'
#
# It also allows you to update the avatar through the member:
#
# params = { :member => { :avatar_attributes => { :id => '2', :icon => 'sad' } } }
# member.update_attributes params[:member]
# member.avatar.icon # => 'sad'
#
# By default you will only be able to set and update attributes on the
# associated model. If you want to destroy the associated model through the
# attributes hash, you have to enable it first using the
# <tt>:allow_destroy</tt> option.
#
# class Member < ActiveRecord::Base
# has_one :avatar
# accepts_nested_attributes_for :avatar, :allow_destroy => true
# end
#
# Now, when you add the <tt>_destroy</tt> key to the attributes hash, with a
# value that evaluates to +true+, you will destroy the associated model:
#
# member.avatar_attributes = { :id => '2', :_destroy => '1' }
# member.avatar.marked_for_destruction? # => true
# member.save
# member.reload.avatar # => nil
#
# Note that the model will _not_ be destroyed until the parent is saved.
#
# === One-to-many
#
# Consider a member that has a number of posts:
#
# class Member < ActiveRecord::Base
# has_many :posts
# accepts_nested_attributes_for :posts
# end
#
# You can now set or update attributes on an associated post model through
# the attribute hash.
#
# For each hash that does _not_ have an <tt>id</tt> key a new record will
# be instantiated, unless the hash also contains a <tt>_destroy</tt> key
# that evaluates to +true+.
#
# params = { :member => {
# :name => 'joe', :posts_attributes => [
# { :title => 'Kari, the awesome Ruby documentation browser!' },
# { :title => 'The egalitarian assumption of the modern citizen' },
# { :title => '', :_destroy => '1' } # this will be ignored
# ]
# }}
#
# member = Member.create(params['member'])
# member.posts.length # => 2
# member.posts.first.title # => 'Kari, the awesome Ruby documentation browser!'
# member.posts.second.title # => 'The egalitarian assumption of the modern citizen'
#
# You may also set a :reject_if proc to silently ignore any new record
# hashes if they fail to pass your criteria. For example, the previous
# example could be rewritten as:
#
# class Member < ActiveRecord::Base
# has_many :posts
# accepts_nested_attributes_for :posts, :reject_if => proc { |attributes| attributes['title'].blank? }
# end
#
# params = { :member => {
# :name => 'joe', :posts_attributes => [
# { :title => 'Kari, the awesome Ruby documentation browser!' },
# { :title => 'The egalitarian assumption of the modern citizen' },
# { :title => '' } # this will be ignored because of the :reject_if proc
# ]
# }}
#
# member = Member.create(params['member'])
# member.posts.length # => 2
# member.posts.first.title # => 'Kari, the awesome Ruby documentation browser!'
# member.posts.second.title # => 'The egalitarian assumption of the modern citizen'
#
# Alternatively, :reject_if also accepts a symbol for using methods:
#
# class Member < ActiveRecord::Base
# has_many :posts
# accepts_nested_attributes_for :posts, :reject_if => :new_record?
# end
#
# class Member < ActiveRecord::Base
# has_many :posts
# accepts_nested_attributes_for :posts, :reject_if => :reject_posts
#
# def reject_posts(attributed)
# attributed['title'].blank?
# end
# end
#
# If the hash contains an <tt>id</tt> key that matches an already
# associated record, the matching record will be modified:
#
# member.attributes = {
# :name => 'Joe',
# :posts_attributes => [
# { :id => 1, :title => '[UPDATED] An, as of yet, undisclosed awesome Ruby documentation browser!' },
# { :id => 2, :title => '[UPDATED] other post' }
# ]
# }
#
# member.posts.first.title # => '[UPDATED] An, as of yet, undisclosed awesome Ruby documentation browser!'
# member.posts.second.title # => '[UPDATED] other post'
#
# By default the associated records are protected from being destroyed. If
# you want to destroy any of the associated records through the attributes
# hash, you have to enable it first using the <tt>:allow_destroy</tt>
# option. This will allow you to also use the <tt>_destroy</tt> key to
# destroy existing records:
#
# class Member < ActiveRecord::Base
# has_many :posts
# accepts_nested_attributes_for :posts, :allow_destroy => true
# end
#
# params = { :member => {
# :posts_attributes => [{ :id => '2', :_destroy => '1' }]
# }}
#
# member.attributes = params['member']
# member.posts.detect { |p| p.id == 2 }.marked_for_destruction? # => true
# member.posts.length # => 2
# member.save
# member.reload.posts.length # => 1
#
# === Saving
#
# All changes to models, including the destruction of those marked for
# destruction, are saved and destroyed automatically and atomically when
# the parent model is saved. This happens inside the transaction initiated
# by the parents save method. See ActiveRecord::AutosaveAssociation.
#
# === Using with attr_accessible
#
# The use of <tt>attr_accessible</tt> can interfere with nested attributes
# if you're not careful. For example, if the <tt>Member</tt> model above
# was using <tt>attr_accessible</tt> like this:
#
# attr_accessible :name
#
# You would need to modify it to look like this:
#
# attr_accessible :name, :posts_attributes
#
# === Validating the presence of a parent model
#
# If you want to validate that a child record is associated with a parent
# record, you can use <tt>validates_presence_of</tt> and
# <tt>inverse_of</tt> as this example illustrates:
#
# class Member < ActiveRecord::Base
# has_many :posts, :inverse_of => :member
# accepts_nested_attributes_for :posts
# end
#
# class Post < ActiveRecord::Base
# belongs_to :member, :inverse_of => :posts
# validates_presence_of :member
# end
module ClassMethods
REJECT_ALL_BLANK_PROC = proc { |attributes| attributes.all? { |_, value| value.blank? } }
# Defines an attributes writer for the specified association(s). If you
# are using <tt>attr_protected</tt> or <tt>attr_accessible</tt>, then you
# will need to add the attribute writer to the allowed list.
#
# Supported options:
# [:allow_destroy]
# If true, destroys any members from the attributes hash with a
# <tt>_destroy</tt> key and a value that evaluates to +true+
# (eg. 1, '1', true, or 'true'). This option is off by default.
# [:reject_if]
# Allows you to specify a Proc or a Symbol pointing to a method
# that checks whether a record should be built for a certain attribute
# hash. The hash is passed to the supplied Proc or the method
# and it should return either +true+ or +false+. When no :reject_if
# is specified, a record will be built for all attribute hashes that
# do not have a <tt>_destroy</tt> value that evaluates to true.
# Passing <tt>:all_blank</tt> instead of a Proc will create a proc
# that will reject a record where all the attributes are blank.
# [:limit]
# Allows you to specify the maximum number of the associated records that
# can be processed with the nested attributes. If the size of the
# nested attributes array exceeds the specified limit, NestedAttributes::TooManyRecords
# exception is raised. If omitted, any number associations can be processed.
# Note that the :limit option is only applicable to one-to-many associations.
# [:update_only]
# Allows you to specify that an existing record may only be updated.
# A new record may only be created when there is no existing record.
# This option only works for one-to-one associations and is ignored for
# collection associations. This option is off by default.
#
# Examples:
# # creates avatar_attributes=
# accepts_nested_attributes_for :avatar, :reject_if => proc { |attributes| attributes['name'].blank? }
# # creates avatar_attributes=
# accepts_nested_attributes_for :avatar, :reject_if => :all_blank
# # creates avatar_attributes= and posts_attributes=
# accepts_nested_attributes_for :avatar, :posts, :allow_destroy => true
def accepts_nested_attributes_for(*attr_names)
options = { :allow_destroy => false, :update_only => false }
options.update(attr_names.extract_options!)
options.assert_valid_keys(:allow_destroy, :reject_if, :limit, :update_only)
options[:reject_if] = REJECT_ALL_BLANK_PROC if options[:reject_if] == :all_blank
attr_names.each do |association_name|
if reflection = reflect_on_association(association_name)
reflection.options[:autosave] = true
add_autosave_association_callbacks(reflection)
nested_attributes_options = self.nested_attributes_options.dup
nested_attributes_options[association_name.to_sym] = options
self.nested_attributes_options = nested_attributes_options
type = (reflection.collection? ? :collection : :one_to_one)
# def pirate_attributes=(attributes)
# assign_nested_attributes_for_one_to_one_association(:pirate, attributes, mass_assignment_options)
# end
class_eval <<-eoruby, __FILE__, __LINE__ + 1
if method_defined?(:#{association_name}_attributes=)
remove_method(:#{association_name}_attributes=)
end
def #{association_name}_attributes=(attributes)
assign_nested_attributes_for_#{type}_association(:#{association_name}, attributes, mass_assignment_options)
end
eoruby
else
raise ArgumentError, "No association found for name `#{association_name}'. Has it been defined yet?"
end
end
end
end
# Returns ActiveRecord::AutosaveAssociation::marked_for_destruction? It's
# used in conjunction with fields_for to build a form element for the
# destruction of this association.
#
# See ActionView::Helpers::FormHelper::fields_for for more info.
def _destroy
marked_for_destruction?
end
private
# Attribute hash keys that should not be assigned as normal attributes.
# These hash keys are nested attributes implementation details.
UNASSIGNABLE_KEYS = %w( id _destroy )
# Assigns the given attributes to the association.
#
# If update_only is false and the given attributes include an <tt>:id</tt>
# that matches the existing record's id, then the existing record will be
# modified. If update_only is true, a new record is only created when no
# object exists. Otherwise a new record will be built.
#
# If the given attributes include a matching <tt>:id</tt> attribute, or
# update_only is true, and a <tt>:_destroy</tt> key set to a truthy value,
# then the existing record will be marked for destruction.
def assign_nested_attributes_for_one_to_one_association(association_name, attributes, assignment_opts = {})
options = self.nested_attributes_options[association_name]
attributes = attributes.with_indifferent_access
if (options[:update_only] || !attributes['id'].blank?) && (record = send(association_name)) &&
(options[:update_only] || record.id.to_s == attributes['id'].to_s)
assign_to_or_mark_for_destruction(record, attributes, options[:allow_destroy], assignment_opts) unless call_reject_if(association_name, attributes)
elsif attributes['id'].present? && !assignment_opts[:without_protection]
raise_nested_attributes_record_not_found(association_name, attributes['id'])
elsif !reject_new_record?(association_name, attributes)
method = "build_#{association_name}"
if respond_to?(method)
send(method, attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
else
raise ArgumentError, "Cannot build association #{association_name}. Are you trying to build a polymorphic one-to-one association?"
end
end
end
# Assigns the given attributes to the collection association.
#
# Hashes with an <tt>:id</tt> value matching an existing associated record
# will update that record. Hashes without an <tt>:id</tt> value will build
# a new record for the association. Hashes with a matching <tt>:id</tt>
# value and a <tt>:_destroy</tt> key set to a truthy value will mark the
# matched record for destruction.
#
# For example:
#
# assign_nested_attributes_for_collection_association(:people, {
# '1' => { :id => '1', :name => 'Peter' },
# '2' => { :name => 'John' },
# '3' => { :id => '2', :_destroy => true }
# })
#
# Will update the name of the Person with ID 1, build a new associated
# person with the name `John', and mark the associated Person with ID 2
# for destruction.
#
# Also accepts an Array of attribute hashes:
#
# assign_nested_attributes_for_collection_association(:people, [
# { :id => '1', :name => 'Peter' },
# { :name => 'John' },
# { :id => '2', :_destroy => true }
# ])
def assign_nested_attributes_for_collection_association(association_name, attributes_collection, assignment_opts = {})
options = self.nested_attributes_options[association_name]
unless attributes_collection.is_a?(Hash) || attributes_collection.is_a?(Array)
raise ArgumentError, "Hash or Array expected, got #{attributes_collection.class.name} (#{attributes_collection.inspect})"
end
if options[:limit] && attributes_collection.size > options[:limit]
raise TooManyRecords, "Maximum #{options[:limit]} records are allowed. Got #{attributes_collection.size} records instead."
end
if attributes_collection.is_a? Hash
keys = attributes_collection.keys
attributes_collection = if keys.include?('id') || keys.include?(:id)
Array.wrap(attributes_collection)
else
attributes_collection.values
end
end
association = association(association_name)
existing_records = if association.loaded?
association.target
else
attribute_ids = attributes_collection.map {|a| a['id'] || a[:id] }.compact
attribute_ids.empty? ? [] : association.scoped.where(association.klass.primary_key => attribute_ids)
end
attributes_collection.each do |attributes|
attributes = attributes.with_indifferent_access
if attributes['id'].blank?
unless reject_new_record?(association_name, attributes)
association.build(attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
end
elsif existing_record = existing_records.detect { |record| record.id.to_s == attributes['id'].to_s }
unless association.loaded? || call_reject_if(association_name, attributes)
# Make sure we are operating on the actual object which is in the association's
# proxy_target array (either by finding it, or adding it if not found)
target_record = association.target.detect { |record| record == existing_record }
if target_record
existing_record = target_record
else
association.add_to_target(existing_record)
end
end
if !call_reject_if(association_name, attributes)
assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy], assignment_opts)
end
elsif assignment_opts[:without_protection]
association.build(attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
else
raise_nested_attributes_record_not_found(association_name, attributes['id'])
end
end
end
# Updates a record with the +attributes+ or marks it for destruction if
# +allow_destroy+ is +true+ and has_destroy_flag? returns +true+.
def assign_to_or_mark_for_destruction(record, attributes, allow_destroy, assignment_opts)
record.assign_attributes(attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
record.mark_for_destruction if has_destroy_flag?(attributes) && allow_destroy
end
# Determines if a hash contains a truthy _destroy key.
def has_destroy_flag?(hash)
ConnectionAdapters::Column.value_to_boolean(hash['_destroy'])
end
# Determines if a new record should be build by checking for
# has_destroy_flag? or if a <tt>:reject_if</tt> proc exists for this
# association and evaluates to +true+.
def reject_new_record?(association_name, attributes)
has_destroy_flag?(attributes) || call_reject_if(association_name, attributes)
end
def call_reject_if(association_name, attributes)
return false if has_destroy_flag?(attributes)
case callback = self.nested_attributes_options[association_name][:reject_if]
when Symbol
method(callback).arity == 0 ? send(callback) : send(callback, attributes)
when Proc
callback.call(attributes)
end
end
def raise_nested_attributes_record_not_found(association_name, record_id)
raise RecordNotFound, "Couldn't find #{self.class.reflect_on_association(association_name).klass.name} with ID=#{record_id} for #{self.class.name} with ID=#{id}"
end
def unassignable_keys(assignment_opts)
assignment_opts[:without_protection] ? UNASSIGNABLE_KEYS - %w[id] : UNASSIGNABLE_KEYS
end
end
end
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