diff options
Diffstat (limited to 'actionpack/lib/action_view')
| -rw-r--r-- | actionpack/lib/action_view/helpers/form_helper.rb | 196 |
1 files changed, 187 insertions, 9 deletions
diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb index a85751c657..2ac2427884 100644 --- a/actionpack/lib/action_view/helpers/form_helper.rb +++ b/actionpack/lib/action_view/helpers/form_helper.rb @@ -269,10 +269,12 @@ module ActionView options[:url] ||= polymorphic_path(object_or_array) end - # Creates a scope around a specific model object like form_for, but doesn't create the form tags themselves. This makes - # fields_for suitable for specifying additional model objects in the same form: + # Creates a scope around a specific model object like form_for, but + # doesn't create the form tags themselves. This makes fields_for suitable + # for specifying additional model objects in the same form. + # + # === Generic Examples # - # ==== Examples # <% form_for @person, :url => { :action => "update" } do |person_form| %> # First name: <%= person_form.text_field :first_name %> # Last name : <%= person_form.text_field :last_name %> @@ -282,20 +284,166 @@ module ActionView # <% end %> # <% end %> # - # ...or if you have an object that needs to be represented as a different parameter, like a Client that acts as a Person: + # ...or if you have an object that needs to be represented as a different + # parameter, like a Client that acts as a Person: # # <% fields_for :person, @client do |permission_fields| %> # Admin?: <%= permission_fields.check_box :admin %> # <% end %> # - # ...or if you don't have an object, just a name of the parameter + # ...or if you don't have an object, just a name of the parameter: # # <% fields_for :person do |permission_fields| %> # Admin?: <%= permission_fields.check_box :admin %> # <% end %> # - # Note: This also works for the methods in FormOptionHelper and DateHelper that are designed to work with an object as base, - # like FormOptionHelper#collection_select and DateHelper#datetime_select. + # Note: This also works for the methods in FormOptionHelper and + # DateHelper that are designed to work with an object as base, like + # FormOptionHelper#collection_select and DateHelper#datetime_select. + # + # === Nested Attributes Examples + # + # When the object belonging to the current scope has a nested attribute + # writer for a certain attribute, fields_for will yield a new scope + # for that attribute. This allows you to create forms that set or change + # the attributes of a parent object and its associations in one go. + # + # Nested attribute writers are normal setter methods named after an + # association. The most common way of defining these writers is either + # with +accepts_nested_attributes_for+ in a model definition or by + # defining a method with the proper name. For example: the attribute + # writer for the association <tt>:address</tt> is called + # <tt>address_attributes=</tt>. + # + # Whether a one-to-one or one-to-many style form builder will be yielded + # depends on whether the normal reader method returns a _single_ object + # or an _array_ of objects. + # + # ==== One-to-one + # + # Consider a Person class which returns a _single_ Address from the + # <tt>address</tt> reader method and responds to the + # <tt>address_attributes=</tt> writer method: + # + # class Person + # def address + # @address + # end + # + # def address_attributes=(attributes) + # # Process the attributes hash + # end + # end + # + # This model can now be used with a nested fields_for, like so: + # + # <% form_for @person, :url => { :action => "update" } do |person_form| %> + # ... + # <% person_form.fields_for :address do |address_fields| %> + # Street : <%= address_fields.text_field :street %> + # Zip code: <%= address_fields.text_field :zip_code %> + # <% end %> + # <% end %> + # + # When address is already an association on a Person you can use + # +accepts_nested_attributes_for+ to define the writer method for you: + # + # class Person < ActiveRecord::Base + # has_one :address + # accepts_nested_attributes_for :address + # end + # + # If you want to destroy the associated model through the form, you have + # to enable it first using the <tt>:allow_destroy</tt> option for + # +accepts_nested_attributes_for+: + # + # class Person < ActiveRecord::Base + # has_one :address + # accepts_nested_attributes_for :address, :allow_destroy => true + # end + # + # Now, when you use a form element with the <tt>_delete</tt> parameter, + # with a value that evaluates to +true+, you will destroy the associated + # model (eg. 1, '1', true, or 'true'): + # + # <% form_for @person, :url => { :action => "update" } do |person_form| %> + # ... + # <% person_form.fields_for :address do |address_fields| %> + # ... + # Delete: <%= address_fields.check_box :_delete %> + # <% end %> + # <% end %> + # + # ==== One-to-many + # + # Consider a Person class which returns an _array_ of Project instances + # from the <tt>projects</tt> reader method and responds to the + # <tt>projects_attributes=</tt> writer method: + # + # class Person + # def projects + # [@project1, @project2] + # end + # + # def projects_attributes=(attributes) + # # Process the attributes hash + # end + # end + # + # This model can now be used with a nested fields_for. The block given to + # the nested fields_for call will be repeated for each instance in the + # collection: + # + # <% form_for @person, :url => { :action => "update" } do |person_form| %> + # ... + # <% person_form.fields_for :projects do |project_fields| %> + # <% if project_fields.object.active? %> + # Name: <%= project_fields.text_field :name %> + # <% end %> + # <% end %> + # <% end %> + # + # It's also possible to specify the instance to be used: + # + # <% form_for @person, :url => { :action => "update" } do |person_form| %> + # ... + # <% @person.projects.each do |project| %> + # <% if project.active? %> + # <% person_form.fields_for :projects, project do |project_fields| %> + # Name: <%= project_fields.text_field :name %> + # <% end %> + # <% end %> + # <% end %> + # <% end %> + # + # When projects is already an association on Person you can use + # +accepts_nested_attributes_for+ to define the writer method for you: + # + # class Person < ActiveRecord::Base + # has_many :projects + # accepts_nested_attributes_for :projects + # end + # + # If you want to destroy any of the associated models through the + # form, you have to enable it first using the <tt>:allow_destroy</tt> + # option for +accepts_nested_attributes_for+: + # + # class Person < ActiveRecord::Base + # has_many :projects + # accepts_nested_attributes_for :projects, :allow_destroy => true + # end + # + # This will allow you to specify which models to destroy in the + # attributes hash by adding a form element for the <tt>_delete</tt> + # parameter with a value that evaluates to +true+ + # (eg. 1, '1', true, or 'true'): + # + # <% form_for @person, :url => { :action => "update" } do |person_form| %> + # ... + # <% person_form.fields_for :projects do |project_fields| %> + # Delete: <%= project_fields.check_box :_delete %> + # <% end %> + # <% end %> def fields_for(record_or_name_or_array, *args, &block) raise ArgumentError, "Missing block" unless block_given? options = args.extract_options! @@ -760,7 +908,11 @@ module ActionView case record_or_name_or_array when String, Symbol - name = "#{object_name}#{index}[#{record_or_name_or_array}]" + if nested_attributes_association?(record_or_name_or_array) + return fields_for_with_nested_attributes(record_or_name_or_array, args, block) + else + name = "#{object_name}#{index}[#{record_or_name_or_array}]" + end when Array object = record_or_name_or_array.last name = "#{object_name}#{index}[#{ActionController::RecordIdentifier.singular_class_name(object)}]" @@ -802,6 +954,32 @@ module ActionView def objectify_options(options) @default_options.merge(options.merge(:object => @object)) end + + def nested_attributes_association?(association_name) + @object.respond_to?("#{association_name}_attributes=") + end + + def fields_for_with_nested_attributes(association_name, args, block) + name = "#{object_name}[#{association_name}_attributes]" + association = @object.send(association_name) + + if association.is_a?(Array) + children = args.first.respond_to?(:new_record?) ? [args.first] : association + + children.map do |child| + child_name = "#{name}[#{ child.new_record? ? new_child_id : child.id }]" + @template.fields_for(child_name, child, *args, &block) + end.join + else + @template.fields_for(name, association, *args, &block) + end + end + + def new_child_id + value = (@child_counter ||= 1) + @child_counter += 1 + "new_#{value}" + end end end @@ -809,4 +987,4 @@ module ActionView cattr_accessor :default_form_builder self.default_form_builder = ::ActionView::Helpers::FormBuilder end -end +end
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