Tags

Tags forms Controller

Multi-value chips + free create — a native text input carrying a comma-joined value, progressively enhanced into a chips UI. JS off: a usable comma-separated text field. JS on: type + Enter/comma creates a chip, blur commits a leftover token, × removes; the native input stays as the submitted value.

Layer: L1 surface · Recipe: multi-label-form — multi free-form labels. Curriculum: AGENTS.md; pick matrix: docs/agent/pick-a-surface.md; blast radius: CONSUMER_MAP.md.

Copy this

html
<label class="field hm-measure" for="hm-tags-field"><span class="field__label">Labels</span><input id="hm-tags-field" name="labels" type="text" data-tags class="form-input" value="urgent,backend" placeholder="Add a label…"></label>

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="tags-root" data-dz-region>…</div>

How to use it

Seams

  • native input value is a comma-joined tag string — the permanent submit shape
  • chips UI rewrites the native input on every add/remove and fires change

Do / Don't

DoDon't
keep the native input as the form value under the chips rootpost a JSON array the server has never seen from a plain field

Pitfalls

  • JS off: type a, b, c — server splits on comma; do not require the chips UI
  • dedupe/trim/skip-empty on add; paste splits on comma and newline

Keyboard / AT

  • chips are role=list of listitem; each × is labelled Remove {tag}
  • Enter or comma creates a chip; blur commits leftover; Backspace on empty entry removes the last

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/tags.py

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

NodeAttrConstraint
[data-tags]namepresent (any value)

Ingestion model TagsField

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

FieldTypeRequired
namestringrequired
field_idstringrequired
labelstringrequired
tagsarrayoptional
placeholderstringoptional

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. Sample model: label=Labels.

python
def render(field: TagsField) -> str:
    joined = ",".join(field.tags)
    return (
        f'<label class="dz-field" for="{html.escape(field.field_id, quote=True)}">'
        f'<span class="dz-field__label">{html.escape(field.label)}</span>'
        f'<input id="{html.escape(field.field_id, quote=True)}" '
        f'name="{html.escape(field.name, quote=True)}" type="text" data-dz-tags '
        f'class="dz-form-input" value="{html.escape(joined, quote=True)}" '
        f'placeholder="{html.escape(field.placeholder, quote=True)}"></label>'
    )

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

Notes

Progressive enhancement: the server renders a plain <input type="text" data-tags> whose value is a COMMA-JOINED tag string — usable and submittable with no JS (type a, b, c; the server splits on comma), native required intact. Seeded non-empty values enhance on DOM ready; empty fields enhance on first interaction. tags.js wraps the input in a .tags root — a role="list" of removable chips + a borderless entry — and hides the native input (kept in the DOM as the submitted value). Every add/remove rewrites the native input to the comma-joined chip list and fires change, so the submit shape never changes. Type + Enter or comma creates a chip (trim/dedup/skip-empty); leftover typed text commits on blur (must not vanish — cycle 2131); paste splits on comma/newline; × or Backspace-on-empty removes a chip; add/remove is announced via a visually-hidden aria-live region.

Source files

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

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