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

# RelevantSort

> Lets users switch between search modes, exhaustive or relevant sorting.

export const Facet = () => <Tooltip tip="An attribute in your records that lets users filter or group results (for example, by color, brand, or price)." cta="Faceting" href="/doc/guides/managing-results/refine-results/faceting">
    facet
  </Tooltip>;

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="ios"
    baseHref="/doc/api-reference/widgets/relevant-sort"
    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" },
]}
  />
</div>

```swift Signature theme={"system"}
RelevantSortConnector<Controller: RelevantSortController, Output>(
  searcher: SingleIndexSearcher,
  interactor: RelevantSortInteractor,
  controller: Controller,
  presenter: RelevantSortPresenter<Output>
)

RelevantSortConnector<Controller: RelevantSortController, Output>(
  searcher: SingleIndexSearcher,
  interactor: RelevantSortInteractor,
  controller: Controller,
  presenter: RelevantSortTextualPresenter
)
```

<Card title="Explore example code" icon="github" href="https://github.com/algolia/instantsearch-ios/tree/master/Examples/Showcase">
  Browse the RelevantSort example code on GitHub.
</Card>

## About this widget

Virtual indices let you use [relevant sort](/doc/guides/managing-results/refine-results/sorting/in-depth/relevant-sort),
a sorting mechanism that favors relevancy over the attribute you're sorting on.
The `relevantSort` widget displays the current search mode when searching in a virtual replica index,
and allows users to switch between relevant and regular sorting,
which is more exhaustive but can return less relevant results.

## Examples

Instantiate a `RelevantSortConnector`.

```swift Swift icon=code theme={"system"}
let searcher = HitsSearcher(appID: "YourApplicationID",
                            apiKey: "YourSearchOnlyAPIKey",
                            indexName: "virtual_replica_index")
let relevantSortController: ButtonRelevantSortController = .init()
let relevantSortConnector: RelevantSortConnector = .init(searcher: searcher, controller: relevantSortController)
```

## Parameters

<ResponseField name="searcher" type="HitsSearcher" required>
  The [`Searcher`](/doc/api-reference/widgets/instantsearch/ios) that handles your searches.
</ResponseField>

<ResponseField name="interactor" type="RelevantSortInteractor" post={["default: .init()"]} required>
  The logic to toggle relevant Sort.
</ResponseField>

<ResponseField name="controller" type="RelevantSortController" post={["default: nil"]}>
  Controller that presents and can toggle the Relevant Sort priority state.
</ResponseField>

<ResponseField name="presenter" type="RelevantSortPresenter<Output> | RelevantSortTextualPresenter" post={["default: DefaultPresenter.RelevantSort.present"]} required>
  Presenter transforming the Relevant sort priority state to its representation for a controller.
</ResponseField>

## Presenter

<ParamField body="RelevantSort Presenter" type="RelevantSortPresenter<Output> | RelevantSortTextualPresenter" default="DefaultPresenter.RelevantSort.present" required>
  Presenter transforming the relevant sort priority state to its representation for a controller.
  Default presenter transforms relevant sort priority to `RelevantSortTextualRepresentation?`
  providing a tuple of string constants in English.

  ```swift Swift icon=code theme={"system"}
  public static func present(_ priority: RelevantSortPriority?) -> RelevantSortTextualRepresentation? {
      switch priority {
      case .some(.hitsCount):
        return ("Currently showing all results.", "Show more relevant results")
      case .some(.relevancy):
        return ("We removed some search results to show you the most relevants ones.", "Show all results")
      default:
        return nil
      }
    }
  ```
</ParamField>

## Low-level API

If you want to fully control the `RelevantSort` components and connect them manually,
you can use the following components:

* `Searcher`. The [`Searcher`](/doc/api-reference/widgets/instantsearch/ios) that handles your searches.
* `RelevantSortInteractor`. Relevant sort priority toggling logic.
* `RelevantSortController`. The controller that presents and toggles the Relevant sort priority state.
* `RelevantSortPresenter<Output>`. Optional. Generic presenter transforming the Relevant Sort priority state to its representation for a controller.

```swift Swift icon=code theme={"system"}
let searcher = HitsSearcher(appID: "YourApplicationID",
                            apiKey: "YourSearchOnlyAPIKey",
                            indexName: "virtual_replica_index")

let relevantSortInteractor = RelevantSortInteractor()
let relevantSortController: ButtonRelevantSortController = .init()

relevantSortInteractor.connectSearcher(searcher)

let relevantSortpresenter: RelevantSortTextualPresenter = { priority in
  switch priority {
  case .some(.hitsCount):
    return ("Currently showing all results.", "Show more relevant results")
  case .some(.relevancy):
    return ("We removed some search results to show you the most relevants ones.", "Show all results")
  default:
    return nil
  }
}

relevantSortInteractor.connectController(relevantSortController, presenter: relevantSortpresenter)
```

## Customizing your view

The controllers provided by default,
like the `ButtonRelevantSortController` work well when you want to use native UIKit with their default behavior like a `UIButton`.

If you want to use another component,
a third-party input view,
or you want to introduce some custom behavior to the already provided UIKit component,
you can create your own controller conforming to the `RelevantSortController` protocol.

### Protocol

`func setItem(_ item: RelevantSortTextualRepresentation?)`

Function called when a new array of indices is defined.

`var didToggle: (() -> Void)? { get set }`

Closure triggered by the controller when the toggle happens (for example, toggle button clicked or switch control state changed)

### Example

```swift Swift icon=code theme={"system"}
public class RelevantSortControl: NSObject, RelevantSortController {

  public let hintLabel: UILabel
  public let toggleButton: UIButton

  public var didToggle: (() -> Void)?

  public init() {
    hintLabel = .init()
    toggleButton = .init()
    super.init()
    toggleButton.addTarget(self, action: #selector(didTapToggleButton), for: .touchUpInside)
  }

  public func setItem(_ item: RelevantSortTextualRepresentation?) {
    hintLabel.isHidden = item == nil
    toggleButton.isHidden = item == nil
    hintLabel.text = item?.hintText
    toggleButton.setTitle(item?.toggleTitle, for: .normal)
  }

  @objc func didTapToggleButton() {
    didToggle?()
  }

}
```

### SwiftUI

InstantSearch provides the `RelevantSortObservableController` data model,
which is an implementation of the `RelevantSortController` protocol adapted for usage with SwiftUI.
`RelevantSortObservableController` must be connected to the `RelevantSortConnector` or `RelevantSortInteractor` like any other `RelevantSortController` implementation.

The example of the SwiftUI view presenting the relevant sort state.

```swift Swift icon=code theme={"system"}
  struct ContentView: View {

  @ObservedObject var relevantSortController: RelevantSortObservableController

  var body: some View {
    VStack {
      if let state = relevantSortController.state {
        HStack {
          Text(state.hintText)
          Spacer()
          Button(state.toggleTitle,
                 action: relevantSortController.toggle)
        }
      }
    }
  }

}
```

If you prefer to create a custom SwiftUI view that presents each <Facet />,
use the `RelevantSortObservableController` as a data model.
It provides the `state` property along with the `toggle` function to streamline the design process of your custom SwiftUI view.