Skeleton

Skeleton Primitive

Loading placeholder with a lifecycle-driven sheen (TASTE-9) — drop it into a swap target while the request is in flight.

Layer: L1 surface · Recipe: unset — see docs/agent/pick-a-surface.md. Curriculum: AGENTS.md; pick matrix: docs/agent/pick-a-surface.md; blast radius: CONSUMER_MAP.md.

Copy this

html
<div class="card card-body hm-measure hm-stack" aria-hidden="true" data-skeleton>
  <div class="hm-demo-row">
    <div class="skeleton" data-shape="circle"></div>
    <div class="hm-grow hm-stack">
      <div class="skeleton" data-shape="text"></div>
      <div class="skeleton" data-shape="text"></div>
    </div>
  </div>
  <div class="skeleton" data-shape="block"></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:

html
<!-- 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:

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

How to use it

No extended guidance authored yet — start from Copy this and the dependency chips (Primitive = markup only; controller = load listed JS; Endpoint = implement Server exchange).

Seams

  • copy the partial under Copy this; keep root class and data-* modifiers so the CSS/JS bundle matches
  • no Server exchange on this part — pure presentation or client chrome
  • satisfy the DOM contract tables (CI stop-ship)

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/skeleton.py

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

NodeAttrConstraint
[data-skeleton]data-skeletonpresent (any value)

Ingestion model Skeleton

Server-side shape before render — one normalisation boundary for producers.

FieldTypeRequired
linesintegeroptional
body_htmlstringoptional

Exemplar render()

Executable in CI: the Python below is render(); the boxed preview is render(EXEMPLARS[0]) — the first fixture the dual-lock tests emit, not a separate widget and not gallery mock data.

python
def render(s: Skeleton) -> str:
    """Model → skeleton-lines stack."""
    if s.body_html.strip():
        inner = s.body_html
    else:
        n = max(1, int(s.lines))
        inner = "".join('<div class="dz-skeleton" data-dz-shape="text"></div>' for _ in range(n))
    return f'<div class="dz-skeleton-lines" data-dz-skeleton>{inner}</div>'

Live output of render(EXEMPLARS[0]) — fixture markup the dual-lock validates (sample field values only).

Notes

Dual-lock root is data-skeleton (contracts/skeleton.py) on the placeholder stack. Purely decorative, so the region is aria-hidden; announce “loading” on the live region that owns the swap. Shapes: data-shape="text|circle|block". The sheen honours prefers-reduced-motion.

Source files

Canonical registration in the registry. No dedicated controller — CSS for this part lives in the layered bundle.

site/registry.py · contracts/skeleton.py