.. include:: ../../../Includes.txt

f:form.radio
============

This ViewHelper allows you to create a radio button element for use in an HTML form. Radio button fields are usually
used in groups, and only a single radio button in a group may be active at one time. A multiple selection - like the one
we see when using checkboxes - isn't possible with radio buttons.

Properties
----------

All the :ref:`universal tag attributes <UniversalTagAttributes>`

All the :ref:`universal form field attributes <UniversalFormFieldAttributes>`

Exclusive properties for the HTML-Element
#########################################

checked
~~~~~~~
:aspect:`Variable type`
    Boolean

:aspect:`Description`
    When active, the radio button field will appear in a checked (active) state.

:aspect:`Default value`
    NULL

:aspect:`Mandatory`
    No

Examples
--------

::

 <f:form.radio name="myExtName[age]" value="1-10" />
 <f:form.radio name="myExtName[age]" value="11-40" />
 <f:form.radio name="myExtName[age]" value="41-99" />


Preselect

::

 <f:form.radio name="myRadioButton" value="someValue" checked="{object.value} == 5" />

Bind to object property

::

 <f:form.radio property="age" value="1-10" />
 <f:form.radio property="age" value="11-40" />
 <f:form.radio property="age" value="41-99" />