ActionView::Helpers::FormHelper

radio_button

API docs (Rails 8.1.4.1) ↗

def radio_button(object_name, method, tag_value, options = {})

Description

Creates an <input> with type="radio" for a model attribute.

Arguments

Changing a value updates the ERB and HTML.

object_name:user

method:plan

tag_value

Used as the value attribute. Also appended to the id attribute, with spaces and . replaced by _, punctuation other than - removed, and the result downcased (Premium Plan becomes user_plan_premium_plan). If id is given in options, nothing is appended to the id attribute and the given value is used as is.

options= {}

:checked = the object's value

truefalse

Adds checked="checked" only for true or "checked". Unlike disabled and the like, "true" and 1 do not add it. By default, it is added when the object's value, converted to a string, equals tag_value.

:value = nil

"basic"

Ignored. The value attribute is set from the tag_value argument.

Common options

Rails handles these options the same way in every helper. Options the HTML spec does not allow on the <input type="radio">, and ones this site considers rarely used, are not listed here.

Shared by form helpers

:name = generated

"q"

Replaces the generated name with the given value. nil omits name.

:id = generated

nil

Replaces the generated id with the given value. nil omits id.

Shared by all helpers

:disabled

truefalse

true adds disabled="disabled"; false omits it. The same goes for every HTML attribute in Rails' list (BOOLEAN_ATTRIBUTES), such as readonly, required and autofocus: any value other than false or nil adds it as attr="attr".

:class

{active: true, hidden: false}

A hash gives the keys whose values are not false or nil, joined with spaces. An array gives its elements joined with spaces, after removing nil, false and empty strings (including whitespace-only strings).

:data

{controller: "tags", tags_suggestions_value: ["ruby", "rails"]}

A hash adds data-* attributes, with _ in the keys converted to -. Array and hash values are converted to JSON strings.

:aria

{describedby: ["name_help", "name_error"], invalid: false}

Like :data, adds aria-* attributes. Array values are joined with spaces, leaving out nil and empty strings (nothing is added if none remain). For a hash value, the keys whose values are not false or nil are joined with spaces.

Any other options become HTML attributes of the <input type="radio">; those with a nil value are left out.

ERB

Changes from the previous output: Added Removed Changed

HTML

Preview

Interacting with the preview updates the form submission.

Form submission

Form data

name	value

Request body

Content-Type:

params