`Loading`¶

Show a polite busy status while a request or deferred component is pending.


Import	`from hedron import Loading`
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.

Loading account activity…

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

app.py

import os

from hedron import Hedron, Loading, Page, Stack, html, swap

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

box = app.region("loading-target")


@app.page("/")
def home() -> Page:
    return Page(
        Stack(
            html.div(Loading("Loading account activity…"), id=box.id),
            html.button(
                "Load activity",
                type="button",
                **{
                    "hx-get": "/activity",
                    "hx-target": box.selector,
                    "hx-swap": "innerHTML",
                },
            ),
        ),
        title="Loading",
    )


@app.fragment("/activity", region=box)
def load():
    return swap(
        html.div(
            html.strong("3 events"),
            html.span("Deployment, approval, and release notes."),
            role="status",
        )
    )

Basic use¶

from hedron import Loading

component = Loading('Loading account activity…')

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

How it works¶

Loading emits a status region with polite live and busy semantics. It is frequently used as Lazy or Poll content and as an HTMX indicator.

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¶

Loading(message='Loading…')

Parameter	Type	Meaning
`message`	`str`	Specific progress message.

Composition and backend behavior¶

Keep Loading 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¶

Name the operation when several requests could be active; remove or replace the status when work completes.

Security¶

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

Common mistakes¶

Do not use Loading for indeterminate work that has failed—render ErrorState.
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

Loading¶