CngxMultiChipGroup

Multi-select chip group. Owns a selectedValues = model<T[]>([]) (the canonical multi-value source) and exposes the parent contract via CNGX_CHIP_GROUP_HOST. Behaves as a role="listbox" aria-multiselectable="true" with CngxRovingTabindex-driven keyboard navigation; consumers project <cngx-chip cngxChipInGroup> children that derive their own aria-selected from this group's isSelected(value).

Mode is static per feedback_select_family_split: this is the multi-select half of the chip-group split.

Internals lean on createSelectionController from @cngx/core/utils for membership tracking - the controller's structural-equality selected snapshot prevents downstream computed cascades from thrashing when a re-emission produces the same logical contents with a different array reference. Mirrors CngxCheckboxGroup's controller wiring.

value is a structural alias of selectedValues so the group satisfies CngxControlValue<T[]> without owning two synchronised models - both names point to the same ModelSignal<T[]> instance.

[keyFn] lets consumers with object-typed values map each value to a stable membership key (typically (v) => v.id). Without it, membership uses identity / primitive equality.

[state] accepts CngxAsyncState<unknown> for async-loaded chip lists; reactively drives aria-busy. Slot directives for skeleton/empty/error are deferred - the harmonized Phase 3-4 group surface ships only the aria-busy projection of [state], and chip-group follows that precedent for cross-family consistency (plan deviation 2026-05-01: see CngxChipGroup JSDoc).

Roving strategy (accepted-debt §5). This molecule uses CngxRovingTabindex (per the harmonized Phase 3-4 group precedent), NOT createChipStripRoving. The strip-roving controller would solve clamp-on-removal automatically but its tabindex contract requires the parent to bind [attr.tabindex] per chip wrapper at the template level - which a content-projected CngxChipInGroup leaf model does not allow. Tracked in form-primitives-accepted-debt §5; UX consequence is a one-shot focus reset to index 0 after mid-strip removal, instead of clamping to the next valid sibling.

Removal flow (plan deviation). Plan revision claimed createChipRemovalHandler from @cngx/forms/select would drive the remove path. That import is a layer violation (@cngx/common/interactive is Level 2; @cngx/forms/select is Level 3). Removal here is a thin controller.deselect(value) - the WeakMap-closure-cache machinery in the select-family handler targets ngTemplateOutlet chip-slot stability, which content- projected chip-in-group leaves do not exhibit.

Per Pillar 1 (Ableitung statt Verwaltung), aria-busy is a computed() from state.status(). Per Pillar 3 (Komposition statt Konfiguration), the group composes CngxRovingTabindex and emits no implicit children - consumers project chip rows themselves.

<cngx-multi-chip-group label="Tags" [(selectedValues)]="tags">
  @for (tag of options(); track tag) {
    <cngx-chip cngxChipInGroup [value]="tag">{{ tag }}</cngx-chip>
  }
</cngx-multi-chip-group>

https://cngxjs.github.io/cngx/examples/#/common/interactive/chip/multi-group/multi-select-chips-with-selection-count https://cngxjs.github.io/cngx/examples/#/forms/field/form-primitives/coming-in-a-follow-up https://cngxjs.github.io/cngx/examples/#/forms/field/form-primitives/reactive-forms-same-atom-just-bind-formcontrol https://cngxjs.github.io/cngx/examples/#/forms/field/form-primitives/signal-forms-drop-the-atom-into-cngx-form-field