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

# Loading

> Shows a loading indicator during pending search requests.

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/loading"
    options={[
{ value: "ios", label: "iOS", description: "InstantSearch iOS" },
{ value: "android", label: "Android", description: "InstantSearch Android" },
{ value: "flutter", label: "Flutter", description: "Algolia for Flutter" },
]}
  />
</div>

```ts Signature theme={"system"}
LoadingConnector(
  searcher: SingleIndexSearcher,
  interactor: LoadingInteractor,
  controller: LoadingController
)
```

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

## About this widget

Components that show a loading indicator during pending requests.

## Examples

Instantiate a `LoadingConnector`.

```swift Swift icon=code theme={"system"}
let searcher = HitsSearcher(appID: "YourApplicationID",
                            apiKey: "YourSearchOnlyAPIKey",
                            indexName: "YourIndexName")
let activityIndicatorController: ActivityIndicatorController = .init(activityIndicator: UIActivityIndicatorView())
let loadingConnector: LoadingConnector = .init(searcher: searcher,
                                               controller: activityIndicatorController)

// Execute a search which will spin the loading indicator until the results arrive
searcher.search()
```

## Parameters

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

<ParamField body="interactor" type="LoadingInteractor" post={["default: .init()"]}>
  The business logic that handles showing a loading indicator.
</ParamField>

<ParamField body="controller" type="LoadingController" post={["default: nil"]}>
  Controller that interfaces with a concrete loading view.
</ParamField>

## Low-level API

If you want to fully control the loading indicator components and connect them manually, you can use these components.

The loading indicator consists of the following components:

* `Searcher`. The [`Searcher`](/doc/api-reference/widgets/instantsearch/ios) that handles your searches.
* `LoadingInteractor`. The logic that handles showing a loading indicator
* `LoadingController`. The controller that interfaces with a concrete loading indicator.

```swift Swift icon=code theme={"system"}
let searcher = HitsSearcher(appID: "YourApplicationID",
                            apiKey: "YourSearchOnlyAPIKey",
                            indexName: "YourIndexName")
let loadingInteractor: LoadingInteractor = .init()
let activityIndicatorController: ActivityIndicatorController = .init(activityIndicator: UIActivityIndicatorView())

loadingInteractor.connectSearcher(searcher)
loadingInteractor.connectController(activityIndicatorController)

// Execute a search which will spin the loading indicator until the results arrive
searcher.search()
```

## Customizing your view

The default controllers, such as `ActivityIndicatorController`,
work well when you want to use native UIKit with their default behavior like `UIActivityIndicatorView`.

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

### Protocol

```swift Swift icon=code theme={"system"}
func setItem(_ item: Bool)`
```

Function called when a new state of the loading indicator is set.

### Example

```swift Swift icon=code theme={"system"}
public class ActivityIndicatorController: LoadingController {

  let activityIndicator: UIActivityIndicatorView

  public init (activityIndicator: UIActivityIndicatorView) {
    self.activityIndicator = activityIndicator
  }

  public func setItem(_ item: Bool) {
    item ? activityIndicator.startAnimating() : activityIndicator.stopAnimating()
  }

}
```

### SwiftUI

InstantSearch provides the `LoadingObservableController` data model,
which is an implementation of the `LoadingController` protocol adapted for usage with SwiftUI.
`LoadingObservableController` must be connected to the `LoadingConnector` or `LoadingConnector` like any other `LoadingController` implementation.

The example of the loading view using the `ProgressView` component provided by SwiftUI.

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

  @ObservedObject var loadingController: LoadingObservableController

  var body: some View {
    VStack {
      Text("Loading")
      if loadingController.isLoading {
        ProgressView()
      }
    }
  }

}
```

If you prefer to create a custom SwiftUI view that presents the loading indicator,
you can directly use the `LoadingObservableController` as a data model.
It provides the `isLoading` property to streamline the design process of your custom SwiftUI view.
