`ToastHost`¶

Frozen out-of-band toast sink at #hedron-toast.


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

Live demo¶

ToastHostFrozen out-of-band toast sink at `#hedron-toast`.

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 ToastHost
component = ToastHost()

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

How it works¶

ToastHost mounts the reserved #hedron-toast live region. Queue, TTL, and danger dismiss live in both hedron-ui.mjs copies (hedron-core static and hedron/static); authors do not write hx-on listeners.

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¶

ToastHost(*, placement: "Literal['top-start', 'top-end', 'bottom-start', 'bottom-end', 'center']" = 'top-end', position: "Literal['fixed', 'sticky', 'flow']" = 'fixed', width: "Literal['content', 'field', 'full']" = 'content', max_width: "Literal['sm', 'md', 'lg']" = 'md', gap: "Literal['xs', 'sm', 'md']" = 'sm', **kwargs: 'object') -> 'None'

Parameter	Type	Meaning
`placement`	`Literal['top-start', 'top-end', 'bottom-start', 'bottom-end', 'center']`	Layout placement for the dock. Default: `'top-end'`.
`position`	`Literal['fixed', 'sticky', 'flow']`	Constructor parameter. Default: `'fixed'`.
`width`	`Literal['content', 'field', 'full']`	Optional width hint (CSS length or pixels). Default: `'content'`.
`max_width`	`Literal['sm', 'md', 'lg']`	Constructor parameter. Default: `'md'`.
`gap`	`Literal['xs', 'sm', 'md']`	Constructor parameter. Default: `'sm'`.

Composition and backend behavior¶

Keep ToastHost 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.

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

Accessibility¶

Keep one ToastHost in the document shell so OOB toasts survive panel swaps.

Security¶

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

Common mistakes¶

Do not invent a second toast host id or attach hx-on handlers for queueing.
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

ToastHost¶