module ActiveFedora::NestedAttributes::ClassMethods
Defines an attributes writer for the specified association(s). If you are using attr_protected
or attr_accessible
, 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
_destroy
key and a value that evaluates totrue
(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
orfalse
. When no :reject_if is specified, a record will be built for all attribute hashes that do not have a_destroy
value that evaluates to true. Passing:all_blank
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
Constants
- REJECT_ALL_BLANK_PROC
Public Instance Methods
# File lib/active_fedora/nested_attributes.rb, line 56 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.autosave = true define_autosave_association_callbacks(reflection) ## TODO this ought to work, but doesn't seem to do the class inheritance right # See https://github.com/samvera/active_fedora/issues/1343 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) generate_association_writer(association_name, type) class_eval <<-eoruby, __FILE__, __LINE__ + 1 remove_possible_method(:#{association_name}_attributes=) def #{association_name}_attributes=(attributes) assign_nested_attributes_for_#{type}_association(:#{association_name}, attributes) end eoruby elsif reflect_on_property(association_name) resource_class.accepts_nested_attributes_for(association_name, options) generate_property_writer(association_name, type) # Delegate the setter to the resource. class_eval <<-eoruby, __FILE__, __LINE__ + 1 remove_possible_method(:#{association_name}_attributes=) def #{association_name}_attributes=(attributes) attribute_will_change!(:#{association_name}) resource.#{association_name}_attributes=(attributes) end eoruby else raise ArgumentError, "No association found for name `#{association_name}'. Has it been defined yet?" end end end
Private Instance Methods
Generates a writer method for this association. Serves as a point for accessing the objects in the association. For example, this method could generate the following:
def pirate_attributes=(attributes) assign_nested_attributes_for_one_to_one_association(:pirate, attributes) end
This redirects the attempts to write objects in an association through the helper methods defined below. Makes it seem like the nested associations are just regular associations.
# File lib/active_fedora/nested_attributes.rb, line 115 def generate_association_writer(association_name, type) generated_association_methods.module_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) end eoruby end
Generates a writer method for this association. Serves as a point for accessing the objects in the association. For example, this method could generate the following:
def pirate_attributes=(attributes) assign_nested_attributes_for_one_to_one_association(:pirate, attributes) end
This redirects the attempts to write objects in an association through the helper methods defined below. Makes it seem like the nested associations are just regular associations.
# File lib/active_fedora/nested_attributes.rb, line 137 def generate_property_writer(association_name, _type) generated_association_methods.module_eval <<-eoruby, __FILE__, __LINE__ + 1 if method_defined?(:#{association_name}_attributes=) remove_method(:#{association_name}_attributes=) end def #{association_name}_attributes=(attributes) attribute_will_change!(:#{association_name}) resource.#{association_name}_attributes=(attributes) end eoruby end