Radio Buttons

Radio buttons allow the user to select one option from a set while seeing all available options.

Design & API Documentation

Installation

npm install @limetech/mdc-radio

Basic Usage

We recommend using MDC Radio with MDC Form Field for enhancements such as label alignment, label activation of the ripple interaction effect, and RTL-awareness.

HTML Structure

<div class="mdc-form-field">
  <div class="mdc-radio">
    <input class="mdc-radio__native-control" type="radio" id="radio-1" name="radios" checked>
    <div class="mdc-radio__background">
      <div class="mdc-radio__outer-circle"></div>
      <div class="mdc-radio__inner-circle"></div>
    </div>
    <div class="mdc-radio__ripple"></div>
  </div>
  <label for="radio-1">Radio 1</label>
</div>

Styles

@import "@limetech/mdc-form-field/mdc-form-field";
@import "@limetech/mdc-radio/mdc-radio";

JavaScript Instantiation

The radio button will work without JavaScript, but you can enhance it with a ripple interaction effect by instantiating MDCRadio on the mdc-radio element. To activate the ripple effect upon interacting with the label, you must also instantiate MDCFormField on the mdc-form-field element and set the MDCRadio instance as its input.

import {MDCFormField} from '@limetech/mdc-form-field';
import {MDCRadio} from '@limetech/mdc-radio';

const radio = new MDCRadio(document.querySelector('.mdc-radio'));
const formField = new MDCFormField(document.querySelector('.mdc-form-field'));
formField.input = radio;

See Importing the JS component for more information on how to import JavaScript.

Variants

Disabled

To disable a radio button, add the mdc-radio--disabled class to the root element and set the disabled attribute on the <input> element. Disabled radio buttons cannot be interacted with and have no visual interaction effect.

<div class="mdc-form-field">
  <div class="mdc-radio mdc-radio--disabled">
    <input class="mdc-radio__native-control" type="radio" id="radio-1" name="radios" disabled>
    <div class="mdc-radio__background">
      <div class="mdc-radio__outer-circle"></div>
      <div class="mdc-radio__inner-circle"></div>
    </div>
    <div class="mdc-radio__ripple"></div>
  </div>
  <label for="radio-1">Radio 1</label>
</div>

Additional Information

Accessibility

Material Design spec advises that touch targets should be at least 48 x 48 px. To meet this requirement, add the mdc-radio--touch class to your radio as follows:

<div class="mdc-touch-target-wrapper">
  <div class="mdc-radio mdc-radio--touch">
    <input class="mdc-radio__native-control" type="radio" id="radio-1" name="radios" checked>
    <div class="mdc-radio__background">
      <div class="mdc-radio__outer-circle"></div>
      <div class="mdc-radio__inner-circle"></div>
    </div>
    <div class="mdc-radio__ripple"></div>
  </div>
</div>

Note that the outer mdc-touch-target-wrapper element is only necessary if you want to avoid potentially overlapping touch targets on adjacent elements (due to collapsing margins).

Style Customization

MDC Radio uses MDC Theme's secondary color by default. Use the following mixins to customize it.

Sass Mixins

Mixin | Description --- | --- mdc-radio-unchecked-stroke-color($color) | Sets the stroke color of an unchecked, enabled radio button mdc-radio-checked-stroke-color($color) | Sets the stroke color of a checked, enabled radio button mdc-radio-ink-color($color) | Sets the ink color of an enabled radio button mdc-radio-disabled-unchecked-stroke-color($color) | Sets the stroke color of an unchecked, disabled radio button mdc-radio-disabled-checked-stroke-color($color) | Sets the stroke color of a checked, disabled radio button mdc-radio-disabled-ink-color($color) | Sets the ink color of a disabled radio button mdc-radio-focus-indicator-color($color) | Sets the color of the focus indicator mdc-radio-touch-target($size, $ripple-size) | Sets radio touch target size which can be more than the ripple size. Param $ripple-size is required for custom ripple size, defaults to $mdc-radio-ripple-size. mdc-radio-ripple-size($size) | Sets custom ripple size of radio. mdc-radio-density($density-scale) | Sets density scale for radio. Supported density scale values are -3, -2, -1 and 0 (default).

Caveat: Edge and CSS Custom Properties

In browsers that fully support CSS custom properties, the above mixins will work if you pass in a MDC Theme property (e.g. primary) as an argument. However, Edge does not fully support CSS custom properties. If you are using any of the Sass mixins, you must pass in an actual color value for support in Edge.

MDCRadio Properties and Methods

Property | Value Type | Description --- | --- | --- checked | Boolean | Setter/getter for the radio's checked state disabled | Boolean | Setter/getter for the radio's disabled state. Setter proxies to foundation's setDisabled method value | String | Setter/getter for the radio's value

Usage within Web Frameworks

If you are using a JavaScript framework, such as React or Angular, you can create a Radio button for your framework. Depending on your needs, you can use the Simple Approach: Wrapping MDC Web Vanilla Components, or the Advanced Approach: Using Foundations and Adapters. Please follow the instructions here.

MDCRadioAdapter

Method Signature | Description --- | --- setNativeControlDisabled(disabled: boolean) => void | Sets the input's disabled property to the given value addClass(className: string) => void | Adds a class to the root element removeClass(className: string) => void | Removes a class from the root element

MDCRadioFoundation

Method Signature | Description --- | --- setDisabled(disabled: boolean) => void | Sets the disabled value of the native control