> ## Documentation Index
> Fetch the complete documentation index at: https://algolia.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Facet List

> Shows a list of facets for refining search results.

export const FlavorSwitcher = ({current, baseHref = "", options = [], label = "InstantSearch framework"}) => {
  if (options.length === 0) {
    return <div className="not-prose" role="alert" style={{
      margin: "0.25rem 0 1.5rem",
      padding: "0.75rem",
      border: "1px solid #f59e0b",
      borderRadius: "0.625rem",
      color: "inherit",
      fontSize: "0.875rem"
    }}>
        FlavorSwitcher requires at least one option.
      </div>;
  }
  const selected = options.find(option => option.value === current) ?? options[0];
  return <div className="not-prose mint-flavor-switcher">
      <style>{`
        .mint-flavor-switcher {
          --mfs-bg: #ffffff;
          --mfs-bg-hover: #f4f4f5;
          --mfs-bg-current: #eef2ff;
          --mfs-border: #d4d4d8;
          --mfs-fg: #18181b;
          --mfs-muted: #71717a;
          --mfs-accent: #4f46e5;
          position: relative;
          width: min(100%, 19rem);
          margin: 0.25rem 0 1.5rem;
          color: var(--mfs-fg);
          font-size: 0.875rem;
          line-height: 1.25rem;
        }

        .dark .mint-flavor-switcher {
          --mfs-bg: #18181b;
          --mfs-bg-hover: #27272a;
          --mfs-bg-current: #272747;
          --mfs-border: #3f3f46;
          --mfs-fg: #fafafa;
          --mfs-muted: #a1a1aa;
          --mfs-accent: #a5b4fc;
        }

        .mint-flavor-switcher details {
          position: relative;
        }

        .mint-flavor-switcher summary {
          display: flex;
          min-height: 2.75rem;
          box-sizing: border-box;
          align-items: center;
          justify-content: space-between;
          gap: 0.75rem;
          padding: 0.625rem 0.75rem;
          border: 1px solid var(--mfs-border);
          border-radius: 0.625rem;
          background: var(--mfs-bg);
          color: var(--mfs-fg);
          cursor: pointer;
          font-weight: 600;
          list-style: none;
          transition: border-color 150ms ease, box-shadow 150ms ease;
        }

        .mint-flavor-switcher summary::-webkit-details-marker {
          display: none;
        }

        .mint-flavor-switcher summary:hover {
          border-color: var(--mfs-accent);
        }

        .mint-flavor-switcher summary:focus-visible {
          outline: 2px solid var(--mfs-accent);
          outline-offset: 2px;
        }

        .mint-flavor-switcher__label {
          overflow: hidden;
          text-overflow: ellipsis;
          white-space: nowrap;
        }

        .mint-flavor-switcher__chevron {
          flex: none;
          transition: transform 150ms ease;
        }

        .mint-flavor-switcher details[open] .mint-flavor-switcher__chevron {
          transform: rotate(180deg);
        }

        .mint-flavor-switcher__menu {
          position: absolute;
          z-index: 50;
          top: calc(100% + 0.375rem);
          left: 0;
          width: 100%;
          box-sizing: border-box;
          margin: 0;
          padding: 0.375rem;
          border: 1px solid var(--mfs-border);
          border-radius: 0.625rem;
          background: var(--mfs-bg);
          box-shadow: 0 12px 30px rgb(0 0 0 / 16%);
          list-style: none;
        }

        .mint-flavor-switcher__menu li {
          margin: 0;
          padding: 0;
        }

        .mint-flavor-switcher__option {
          display: grid;
          gap: 0.125rem;
          padding: 0.625rem 0.75rem;
          border-radius: 0.4rem;
          color: var(--mfs-fg);
          text-decoration: none;
        }

        .mint-flavor-switcher__option:hover {
          background: var(--mfs-bg-hover);
        }

        .mint-flavor-switcher__option:focus-visible {
          outline: 2px solid var(--mfs-accent);
          outline-offset: -2px;
        }

        .mint-flavor-switcher__option[aria-current="page"] {
          background: var(--mfs-bg-current);
          color: var(--mfs-accent);
        }

        .mint-flavor-switcher__name {
          font-weight: 600;
        }

        .mint-flavor-switcher__description {
          color: var(--mfs-muted);
          font-size: 0.8125rem;
        }

        @media (prefers-reduced-motion: reduce) {
          .mint-flavor-switcher summary,
          .mint-flavor-switcher__chevron {
            transition: none;
          }
        }
      `}</style>

      <details>
        <summary aria-label={`${label}: ${selected.label}`}>
          <span className="mint-flavor-switcher__label">{selected.label}</span>
          <svg className="mint-flavor-switcher__chevron" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
            <path d="m6 9 6 6 6-6" />
          </svg>
        </summary>

        <ul className="mint-flavor-switcher__menu" aria-label={label}>
          {options.map(option => {
    const isCurrent = option.value === selected.value;
    const href = option.href ?? `${baseHref.replace(/\/$/, "")}/${encodeURIComponent(option.value)}`;
    return <li key={option.value}>
                <a className="mint-flavor-switcher__option" href={href} aria-current={isCurrent ? "page" : undefined}>
                  <span className="mint-flavor-switcher__name">
                    {option.label}
                  </span>
                  {option.description ? <span className="mint-flavor-switcher__description">
                      {option.description}
                    </span> : null}
                </a>
              </li>;
  })}
        </ul>
      </details>
    </div>;
};

<div className="mint-flavor-switcher-slot not-prose">
  <FlavorSwitcher
    current="flutter"
    baseHref="/doc/api-reference/widgets/refinement-list"
    options={[
{ value: "js", label: "JavaScript", description: "InstantSearch.js" },
{ value: "react", label: "React", description: "React InstantSearch" },
{ value: "vue", label: "Vue", description: "Vue InstantSearch" },
{ value: "ios", label: "iOS", description: "InstantSearch iOS" },
{ value: "android", label: "Android", description: "InstantSearch Android" },
{ value: "flutter", label: "Flutter", description: "Algolia for Flutter" },
]}
  />
</div>

```dart Signature theme={"system"}
HitsSearcher.buildFacetList(
  _FilterState_ filterState,
  String attribute,
  // Optional parameters
  _FilterOperator_ operator,
  _SelectionMode_ selectionMode,
  _bool_ persistent,
)

```

<Card title="View live demo" icon="monitor-play" href="https://algolia-flutter-showcase.netlify.app/#/?path=facet-list%2Fmultiple-facet-lists">
  Open the live Facet List example in your browser.
</Card>

## About this widget

`FacetList` is a filtering component that displays [facets](/doc/guides/managing-results/refine-results/filtering) and lets users refine their search results by filtering on specific values.

### Requirements

The [`attribute`](#param-attribute) provided to the widget must be in attributes for faceting,
either on the [dashboard](/doc/guides/managing-results/refine-results/faceting/how-to/declaring-attributes-for-faceting-with-dashboard) or using the [`attributesForFaceting`](/doc/api-reference/api-parameters/attributesForFaceting) parameter with the API.

## Examples

### Create facet list

Create `FacetList` with [`HitsSearcher`](/doc/api-reference/widgets/instantsearch/flutter)
and [`FilterState`](/doc/api-reference/widgets/filter-state/flutter):

```dart Dart icon=code theme={"system"}
// Create a FilterState
final filterState = FilterState();

// Create a HitsSearcher
final hitsSearcher = HitsSearcher(
  applicationID: 'YourApplicationID',
  apiKey: 'YourSearchOnlyApiKey',
  indexName: 'YourIndexName',
)..connectFilterState(filterState);

// Create a FacetList
final facetList = hitsSearcher.buildFacetList(
  filterState: filterState,
  attribute: 'YourAttribute',
);
```

### Display facets

Get selectable facet changes by listening to [`facets`](#param-facets) submissions.
Call [`toggle`](#param-toggle) to select or deselect a facet value:

```dart Dart icon=code theme={"system"}
StreamBuilder<List<SelectableFacet>>(
  stream: facetList.facets, // Listen to `facets` stream
  builder: (context, snapshot) {
    if (snapshot.hasData) {
      final facets = snapshot.data ?? [];
      return ListView.builder(
        itemCount: facets.length,
        itemBuilder: (BuildContext context, int index) {
          final selectable = facets[index];
          final facet = selectable.item;
          return ListTile(
            title: Text('${facet.value} (${facet.count})'),
            trailing: selectable.isSelected ? const Icon(Icons.check) : null,
            onTap: () => facetList.toggle(facet.value), // Toggle a facet value on tap
          );
        },
      );
    } else {
      return const LinearProgressIndicator();
    }
  },
);
```

### Dispose

Call [`dispose`](#param-dispose) to release underlying resources:

```dart Dart icon=code theme={"system"}
facetList.dispose();
```

## Parameters

<ParamField body="filterState" type="FilterState" required>
  The [`FilterState`](/doc/api-reference/widgets/filter-state/flutter) that holds your filters.
</ParamField>

<ParamField body="attribute" type="String" required>
  The attribute to filter.
</ParamField>

<ParamField body="operator" type="FilterOperator" post={["default: FilterOperator.or"]}>
  Filters operator, which can either be `FilterOperator.and` or `FilterOperator.or`.

  Use [filters or facet filters](/doc/guides/managing-results/refine-results/filtering/in-depth/filters-and-facetfilters)
  for more complex result refinement.
</ParamField>

<ParamField body="selectionMode" type="SelectionMode" post={["default: SelectionMode.multiple"]}>
  Whether the list can have `SelectionMode.single` or `SelectionMode.multiple` selections.
</ParamField>

<ParamField body="persistent" type="bool" default={false}>
  When `true`, the selection will be kept even if it doesn't match current results anymore.
</ParamField>

## Fields

<ParamField body="facets" type="Stream<List<SelectableFacet>>">
  A stream of facets with their selection status.

  ```dart Dart icon=code theme={"system"}
  facetList.facets.listen((facets) {
    for (var facet in facets) {
      print("${facet.item} ${facet.isSelected ? 'x' : '-'}");
    }
  });
  ```
</ParamField>

<ParamField body="eventTracker" type="FilterEventTracker">
  `FilterEventTracker` instance responsible for sending Insights events related to user interactions with facets,
  such as clicking, viewing, and converting filters. With the `eventTracker`,
  you can track user's behavior, which can help you personalize their search experience.

  ```dart Dart icon=code theme={"system"}
  facetList.eventTracker.clickedFilters(
    indexName: 'INDEX_NAME',
    eventName: 'your_event_name',
    values: ['value1', 'value2'],
  );
  ```
</ParamField>

## Methods

<ParamField body="toggle">
  Select or deselect the provided facet value depending on the current selection state.

  ```dart Dart icon=code theme={"system"}
  facetList.toggle('blue');
  ```
</ParamField>

<ParamField body="snapshot">
  Gets the latest `List<SelectableFacet>` value submitted by [`facets`](#param-facets):

  ```dart Dart icon=code theme={"system"}
  final selectableFacet = facetList.snapshot();
  ```
</ParamField>

<ParamField body="dispose">
  Releases all underlying resources.

  ```dart Dart icon=code theme={"system"}
  facetList.dispose();
  ```
</ParamField>