`Toast`¶

Render a polite, transient-looking status message.


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

Live demo¶

DemoCode

Docs simulation — not a running Hedron server. Interactive demos show a “Simulated HTMX” trace when applicable.

Minimal runnable app.py that reproduces this demo (real Hedron, not the docs simulator):

app.py

import os

from hedron import Hedron, OobHost, Page, Stack, Toast, html, swap

app = Hedron(
    title="Toast demo",
    security="standard",
    explorer="off",
    session_secret=os.environ.get("HEDRON_SESSION_SECRET", "dev-only"),
)

host = app.region("toast-host")


@app.page("/")
def home() -> Page:
    return Page(
        Stack(
            html.button(
                "Copy API key",
                type="button",
                **{
                    "hx-post": "/copy-key",
                    "hx-target": host.selector,
                    "hx-swap": "innerHTML",
                },
            ),
            OobHost(id=host.id),
        ),
        title="Toast",
    )


@app.action("/copy-key", method="POST", fragment_regions=(host,))
def copy():
    return swap(Toast("API key copied.", tone="success"))

Basic use¶

from hedron import Toast
component = Toast('API key copied.', tone='success')

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

How it works¶

Toast emits a polite status region with a tone class and optional TTL. Pair with ToastHost at frozen #hedron-toast. Danger toasts stay until dismissed unless ttl_ms is set; they render a Dismiss control (data-hedron-toast-dismiss) handled by hedron-ui.mjs.

This component can initiate or represent a backend interaction. The live documentation intercepts that interaction with JavaScript and shows the same pending, success, or replacement states without making a real request. In an application, keep the URL, authorization, validation, and returned fragment on the server; JavaScript is only progressive enhancement.

Constructor and parameters¶

Toast(message, *, tone='info', ttl_ms=4000)

Parameter	Type	Meaning
`message`	`str`	Escaped toast text.
`tone`	`info \| success \| warning \| danger`	Visual token.
`ttl_ms`	`int \| None`	Auto-dismiss delay in milliseconds; danger defaults to none.

Composition and backend behavior¶

Keep Toast 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.

Mutating flows must use POST, validate CSRF, authorize on the server, re-validate typed input, and return a bounded fragment. GET remains safe and repeatable; native submit should still work without HTMX.

Accessibility¶

If application JavaScript removes the toast, allow enough reading time, pause any timer on hover or focus, and preserve critical messages elsewhere.

Security¶

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

Common mistakes¶

Never auto-dismiss errors that require a user decision, and do not expect a dismissible constructor option.
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

Toast¶