material-design-lite/src/radio/README.md

Introduction

The Material Design Lite (MDL) radio component is an enhanced version of the standard HTML <input type="radio">, or "radio button" element. A radio button consists of a small circle and, typically, text that clearly communicates a condition that will be set when the user clicks or touches it. Radio buttons always appear in groups of two or more and, while they can be individually selected, can only be deselected by selecting a different radio button in the same group (which deselects all other radio buttons in the group). The MDL radio component allows you to add display and click effects.

Radio buttons are a common feature of most user interfaces, regardless of a site's content or function. Their design and use is therefore an important factor in the overall user experience. See the radio component's Material Design specifications page for details.

The enhanced radio component has a more vivid visual look than a standard radio button, and may be initially or programmatically disabled.

To include an MDL radio component:

 1. Code a <label> element and give it a for attribute whose value is the unique id of the radio button it will contain. The for attribute is optional when the <input> element is contained inside the <label> element, but is recommended for clarity.

<label for="radio1">
...
</label>

 2. Inside the label, code an <input> element and give it a type attribute whose value is "radio". Also give it an id attribute whose value matches the label's for attribute value, and a name attribute whose value identifies the radio button group. Optionally, give it a value attribute whose value provides some information about the radio button for scripting purposes.

<label for="radio1">
  <input type="radio" id="radio1" name="flash" value="on">
</label>

 3. Also inside the label, after the radio button, code a <span> element containing the radio button's text caption.

<label for="radio1">
  <input type="radio" id="radio1" name="flash" value="on">
  <span>Always on</span>
</label>

 4. Add one or more MDL classes, separated by spaces, to the label, checkbox, and caption using the class attribute.

<label for="radio1" class="mdl-radio mdl-js-radio">
  <input type="radio" id="radio1" name="flash" value="on" class="mdl-radio__button">
  <span class="mdl-radio__label">Always on</span>
</label>

 5. Repeat steps 1 through 4 for the other radio components in the group. For each one:

• on the label element, specify a unique for attribute value
• on the input element, specify an id attribute value that matches its label element's for attribute value
• on the input element, specify the same name attribute value for all radio components in the group
• optionally, on the input element, specify a unique value attribute value

The radio components are ready for use.

Example

A group of radio buttons to control a camera's flash setting.

<label class="mdl-radio mdl-js-radio mdl-js-ripple-effect" for="flash1">
  <input checked class="mdl-radio__button" id="flash1" name="flash" type="radio"
   value="on">
  <span class="mdl-radio__label">Always on</span>
</label>
<label class="mdl-radio mdl-js-radio mdl-js-ripple-effect" for="flash2">
  <input class="mdl-radio__button" id="flash2" name="flash" type="radio" value="off">
  <span class="mdl-radio__label">Always off</span>
</label>
<label class="mdl-radio mdl-js-radio mdl-js-ripple-effect" for="flash3">
  <input class="mdl-radio__button" id="flash3" name="flash" type="radio" value="auto">
  <span class="mdl-radio__label">Automatic</span>
</label>

Configuration options

The MDL CSS classes apply various predefined visual and behavioral enhancements to the radio button. The table below lists the available classes and their effects.

MDL class	Effect	Remarks
mdl-radio	Defines label as an MDL component	Required on label element
mdl-js-radio	Assigns basic MDL behavior to label	Required on label element
mdl-radio__button	Applies basic MDL behavior to radio	Required on input element (radio button)
mdl-radio__label	Applies basic MDL behavior to caption	Required on span element (caption)
mdl-js-ripple-effect	Applies ripple click effect	Optional; goes on label element, not input element (radio button)

Note: Disabled versions of all the available radio button types are provided, and are invoked with the standard HTML boolean attribute disabled. <input type="radio" id="radio5" name="flash" class="mdl-radio__button" disabled> This attribute may be added or removed programmatically via scripting.