fields_for

record_name

The prefix of the name and id attributes of the fields in the block.

record_object = nil

nil New @commentPersisted @comment

Uses the given object's values as the initial values of the fields. Defaults to the instance variable with the same name as record_name, if there is one.

options= {}

:index = nil

1

Inserted as an index into the name and id attributes of the fields in the block. nil adds [] instead of an index (comment[][body]).

:namespace = nil

"admin"

Prepended to the id attribute of the fields in the block. The name attribute does not change.

:skip_default_ids = false

truefalse

true omits id from the fields in the block and for from f.label. By default, id is added. Unlike form_with, config.action_view.form_with_generates_ids is not used.

:allow_method_names_outside_object = false

truefalse

true creates fields with no initial value for attributes the model does not have. By default, Rails tries to read such an attribute from the model and raises NoMethodError (try f.text_field :author_name in &block).

:builder = the config value

LabeledFormBuilder

Changes the class of the block's f (a FormBuilder). LabeledFormBuilder on this page overrides FormBuilder's text_field to add a label for the same attribute before the text_field.

fields_for outputs only the content of the block and creates no element of its own. As a result, options not listed here (such as class) do not become HTML attributes; they are passed to the block's form builder as settings.

&block= nil

do |f|
  <%= f.text_field :body %>
end

do |f|
  <%= f.text_field :author_name %>
end

Required. Omitting it raises LocalJumpError.

fields_for

Description

Arguments

ERB

HTML

Preview

Form submission