`Alert`¶

Present an important text message using an appropriate live-region policy.


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

Live demo¶

Saved

Your changes were saved.

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 Alert

component = Alert('Your changes were saved.', tone='success', title='Saved')

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

How it works¶

Alerts group an optional strong title and escaped message with tone styling. Danger messaging uses alert semantics; lower-urgency messages use status semantics to avoid unnecessary interruption.

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¶

Alert(message, *, tone='info', title=None)

Parameter	Type	Meaning
`message`	`str`	Escaped alert text.
`tone`	`info \| success \| warning \| danger`	Visual and semantic urgency.
`title`	`str \| None`	Optional concise heading text.

Composition and backend behavior¶

Keep Alert 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.

This component is primarily presentational; keep any mutation on an explicit action or component route.

Accessibility¶

Reserve assertive alerts for errors requiring immediate attention and move focus only when the next action would otherwise be unclear.

Security¶

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

Common mistakes¶

Alert accepts text, not arbitrary child components; compose a custom semantic region when the message needs structured controls.
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

Alert¶