`RadioGroup`¶

Choose exactly one option from a labelled set.


Import	`from hedron import RadioGroup`
Distribution	`hedron`
Backend activity	No
Normal render mode	`RenderMode.FRAGMENT`

Live demo¶

Billing plan Free Pro

The preview is a local docs simulation (not a running Hedron server). Interactive demos show a “Simulated HTMX” trace when applicable.

Basic use¶

from hedron import RadioGroup
component = RadioGroup('plan', 'Billing plan', [('free', 'Free'), ('pro', 'Pro')], value='free')

Compose under Page for full documents, or return from a fragment route for HTMX swaps.

How it works¶

A native fieldset and legend name the group; every option gets a collision-free ID, shared name, value, and associated label. Pass id= only when outside markup must use a predictable prefix.

This component's core behavior is server-rendered HTML and does not require a browser runtime. The preview is ordinary semantic HTML, so keyboard, form, link, and disclosure behavior comes from the platform.

Constructor and parameters¶

RadioGroup(name, legend, options, *, id=None, value=None, required=False)

Parameter	Type	Meaning
`name`	`str`	Shared submitted field name.
`legend`	`str`	Group label.
`options`	`Sequence[tuple[str, str]]`	Value/label pairs.
`id`	`str \| None`	Optional option-ID prefix; generated collision-free by default.
`value`	`str \| None`	Selected option.
`required`	`bool`	Require one selection.

Composition and backend behavior¶

Keep RadioGroup at the smallest semantic boundary. Fragment routes should return only the replaced region and preserve stable target IDs across success, validation, empty, loading, and error responses.

RadioGroup participates in interaction markup. Pair it with an explicit @app.action POST (and CSRF) when the control mutates state.

Accessibility¶

Keep option labels parallel and make the legend a complete question or category.

Security¶

Escaping and SafeUrl / TrustedHtml are framework concerns; authorization and data exposure remain application code. Redact secrets before rendering.

Common mistakes¶

Use Select when the option set is long or screen space is constrained.
Do not copy docs-preview JavaScript into an application server.

Testing¶

from hedron import RenderMode, render

result = render(component, mode=RenderMode.FRAGMENT)
assert result.html
assert not result.diagnostics

All component demos · Built-in API · Testing

RadioGroup¶