Dialog

Copy this

<!-- icons: include the icon sheet once per page (see the Setup section, #setup) -->
<button class="button" data-variant="primary" data-dialog-open="hm-dialog-demo">Delete workspace…</button>
<dialog class="dialog" id="hm-dialog-demo" aria-labelledby="hm-dialog-demo-title" closedby="any">
  <form method="dialog">
    <div class="dialog__header">
      <h2 class="dialog__title" id="hm-dialog-demo-title">Delete workspace?</h2>
      <button type="submit" class="dialog__close" aria-label="Close dialog"><svg class="icon" aria-hidden="true"><use href="#i-x"/></svg></button>
    </div>
    <div class="dialog__body">
      <p>This permanently deletes the workspace and every record in it. This action cannot be undone.</p>
    </div>
    <div class="dialog__footer"><button type="submit" class="button" data-variant="outline">Cancel</button><button type="submit" class="button" data-variant="destructive" value="confirm">Delete</button></div>
  </form>
</dialog>

Server exchange

This Hyperpart has no server exchange — it is presentation or client chrome only. htmx does not issue a request on this part's behalf. If you put an affordance (hx-*) on a control that uses this markup, that action's exchange belongs to the action, not this part. See Swap contract for host-owned envelopes.

Swap contract

Agent-visible HTMX topology (ADR-0054 / decision 0012). exchange envelope = what the response may re-emit relative to the persistent slot (body_only | outer | none | host_owned | document). dual-lock validates part markup only — not this envelope. Stem: stems/morph-safe-hypermedia.md; decision: docs/decisions/0012-swap-identity-contract.md.

No host HTMX exchange on this part — presentation or client chrome only. exchange envelope: n/a.

If a host wraps this markup in hx-*, that host owns the swap contract (sole identity + envelope). Prefer innerMorph / outerMorph for stable slots; replacement for flash; body-only responses under inner swaps.

Envelope response examples

This part has no owned exchange (envelope n/a). If a host adds hx-*, that host’s envelope applies — typically body_only:

<!-- Host wraps this presentation part with hx-* (host owns envelope) -->
<!-- Prefer: hx-swap="innerMorph" hx-target="#panel-body" -->
<!-- Server returns body_only interior for #panel-body -->
<div class="dz-stack">content…</div>

Do not re-own the slot:

<!-- WRONG: server returns the presentation root with a new id every poll -->
<div id="dialog-root" data-dz-region>…</div>

How to use it

Seams

• addressing: data-dialog-open → showModal on dialog#id (N instances)
• author full dialog HTML (header/body/footer) — chrome you own
• confirm button may carry hx-delete / form submit; closing is native
• pick-a-surface: custom modal body → dialog; yes/no on hx-* → confirm

Do / Don't

Pitfalls

• do not re-implement close with custom overlays — use <dialog> + showModal
• returnValue on the confirm button is the hand-off for form-less actions
• do not use dialog for fleet hx-confirm upgrades — that is confirm (gating)

Keyboard / AT

• Esc dismisses natively; focus is restored to the open trigger
• confirm / cancel are real buttons inside the dialog

Related parts

button

DOM contract

What the emitted HTML must satisfy — the table is the required surface; Python under contracts/ is the package-internal dual-lock CI runs (tests/test_contracts.py), not an app route. Standalone HTMX4: implement the API so responses match this markup. Dazzle: the agent emits SSR that already satisfies it. Do not invent attrs outside these tables. For request/response wiring see Server exchange.

contracts/dialog.py

Required in the DOM: root [data-dialog-open] (part dialog). Emit only these attributes — inventing extras is fine only if controllers ignore them; omitting required ones fails CI (tests/test_contracts.py).

Module source

Import path is monorepo/package-local (from contracts._kit import …). Source-token form often uses data-*; gallery demos above are unprefixed. Do not copy this into app routes.

"""HYPERPART: dialog — native <dialog> open trigger contract."""

from contracts._kit import DomContract, Node, Present

DOM_CONTRACT = DomContract(
    part="dialog",
    root="[data-dz-dialog-open]",
    nodes=(Node("[data-dz-dialog-open]", attrs={"data-dz-dialog-open": Present()}),),
)

__all__ = ["DOM_CONTRACT"]

Notes

Source files

One logical Hyperpart, 4 code items (CSS layered, JS bundled). Bound by HYPERPART: dialog — python tools/hyperpart.py dialog lists them.

site/registry.py · contracts/dialog.py · components/dialog.css:1 · controllers/dz-dialog.js

Composed of

Button