Hover card

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<div class="hover-card" data-hover-card>
  <button type="button" class="hover-card__trigger" aria-expanded="false">@maya</button>
  <div class="hover-card__content" role="tooltip">
    <p class="hover-card__title">Maya Reyes</p>
    <p class="hover-card__description">Operations lead · Online now</p>
  </div>
</div>

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="hover-card-root" data-dz-region>…</div>

How to use it

Seams

• open: CSS :hover/:focus-within OR data-open from controller
• trigger click/tap toggles open; outside click + Escape close
• aria-expanded on the trigger mirrors open state
• death-zone bridge: __content::before covers margin-top gap

Do / Don't

Pitfalls

• do not rely on focus-within alone for touch — load hover-card.js
• do not use hover-card for multi-control forms (use popover/dialog)
• do not omit the trigger class — controller binds .hover-card__trigger

Keyboard / AT

• Keyboard: Tab to trigger + Enter/Space activates button (toggle)
• Escape closes explicit open
• role=tooltip on the panel — keep content non-interactive

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/hover_card.py

Required in the DOM: root .hover-card (part hover-card). 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: hover-card — rich preview on hover/focus/tap.

Dual-lock unit is the card root. Trigger chrome and tooltip body are
host-owned. Class ``.dz-hover-card`` is the stable substrate root.

Open paths:
  * CSS ``:hover`` / ``:focus-within`` (fine pointers + keyboard)
  * ``data-dz-open`` / gallery ``data-open`` via ``controllers/dz-hover-card.js``
    (click/tap — required on iPadOS Safari where focus/hover do not stick)
"""

from contracts._kit import DomContract, Node

DOM_CONTRACT = DomContract(
    part="hover-card",
    root=".dz-hover-card",
    nodes=(Node(".dz-hover-card", attrs={}),),
)

__all__ = ["DOM_CONTRACT"]

Notes

Source files

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

site/registry.py · contracts/hover_card.py · components/hover-card.css:1 · controllers/dz-hover-card.js