Timeline

Copy this

<div class="timeline-region hm-measure-lg">
  <ul class="timeline-list">
    <li class="timeline-item" data-timeline-item>
      <span class="timeline-bullet-wrap"><svg class="timeline-bullet attn-bullet attn-tone-critical" fill="currentColor" viewBox="0 0 20 20" aria-hidden="true"><circle cx="10" cy="10" r="6"/></svg></span>
      <div class="timeline-row">
        <div class="timeline-date">Today</div>
        <div class="timeline-content">
          <p class="timeline-title">Payment failed — retry scheduled</p>
          <p class="timeline-field">Card declined (insufficient funds)</p>
        </div>
      </div>
    </li>
    <li class="timeline-item" data-timeline-item>
      <span class="timeline-bullet-wrap"><svg class="timeline-bullet attn-bullet attn-tone-default" fill="currentColor" viewBox="0 0 20 20" aria-hidden="true"><circle cx="10" cy="10" r="6"/></svg></span>
      <div class="timeline-row">
        <div class="timeline-date">Mon</div>
        <div class="timeline-content">
          <p class="timeline-title">Invoice sent</p>
        </div>
      </div>
    </li>
  </ul>
</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="timeline-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/timeline.py

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

Ingestion model TimelineEvent

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

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.

def render(evt: TimelineEvent) -> str:
    """Model → one ``<li>`` timeline item."""
    title = html.escape(evt.title)
    if evt.drill_url:
        href = html.escape(evt.drill_url, quote=True)
        # Keep p + class for dual-lock/CSS; wrap title text in hub drill
        # (queue/kanban pattern; empty drill_url stays byte-stable plain p).
        title_html = (
            f'<p class="dz-timeline-title"><a href="{href}" data-dz-timeline-drill>{title}</a></p>'
        )
    else:
        title_html = f'<p class="dz-timeline-title">{title}</p>'
    date = html.escape(evt.date_label)
    bullet = evt.bullet_html.strip() or _DEFAULT_BULLET
    return (
        f'<li class="dz-timeline-item" data-dz-timeline-item>'
        f'<span class="dz-timeline-bullet-wrap">{bullet}</span>'
        f'<div class="dz-timeline-row">'
        f'<div class="dz-timeline-date">{date}</div>'
        f'<div class="dz-timeline-content">'
        f"{title_html}"
        f"{evt.fields_html}"
        f"</div>"
        f"</div>"
        f"</li>"
    )

Notes

Source files

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

site/registry.py · contracts/timeline.py