Slider

Copy this

<div class="hm-stack hm-measure">
  <label class="form-label" for="hm-slider-vol">Volume</label>
  <div class="form-slider-group"><input id="hm-slider-vol" type="range" data-slider class="form-slider" min="0" max="100" step="1" value="70"><span data-range-value class="form-slider-value" aria-hidden="true">70</span></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="slider-root" data-dz-region>…</div>

How to use it

Seams

• native <input type=range> is the value source; [data-range-value] is the readout
• each slider group is scoped so many coexist on one page

Do / Don't

Pitfalls

• the visible readout is aria-hidden — the range already announces to AT
• do not invent a custom thumb/track in JS; style the native control

Keyboard / AT

• Arrow keys adjust the native range (browser default)
• focus ring is theme-aware on the track/thumb

Related parts

field

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/slider.py

Required in the DOM: root [data-slider] (part slider). 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: slider — native range group + live value readout."""

from contracts._kit import DomContract, Node

DOM_CONTRACT = DomContract(
    part="slider",
    root="[data-dz-slider]",
    nodes=(
        Node("[data-dz-slider]", attrs={}),
        Node("[data-dz-range-value]", attrs={}),
    ),
)

__all__ = ["DOM_CONTRACT"]

Notes

Source files

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

site/registry.py · contracts/slider.py · base/design-system.css:668 · controllers/dz-slider.js