# Leaderboard

## Opt in

To opt in or join a user into the leaderboard, the following API can be used.

#### Concrete Example

{% tabs %}
{% tab title="Swift" %}

```swift
let service = LeaderboardService()
service.optIn(then: { result in
        switch result {
        case .success:
            // leaderboard opt in successful
            break
        case .failure:
            // error
        }
})
```

{% endtab %}

{% tab title="Kotlin" %}

```kotlin
val service = LeaderboardService()
service.optIn() { result: Result<Content?>? ->
    if (result?.value == null || result.throwable != null) {
        // failure
    } else {
        // Success
        val content = result.value
    }
})
```

{% endtab %}
{% endtabs %}

## Opt out

To opt out or leave the leaderboard, the following API can be used.

#### Concrete Example

{% tabs %}
{% tab title="Swift" %}

```swift
let service = LeaderboardService()
service.optOut(then: { result in
    switch result {
    case .success:
        // opts out successful
        break
    case .failure:
        // error
    }
})
```

{% endtab %}

{% tab title="Kotlin" %}

```kotlin
val service = LeaderboardService()
service.optOut() { result: Result<Content?>? ->
    if (result?.value == null || result.throwable != null) {
        // failure
    } else {
        // Success
        val content = result.value
        completionHandler(content)
    }
})
```

{% endtab %}
{% endtabs %}

## Fetch

To fetch the leaderboard, the following API can be used.

#### Parameters:

* `dateComponents`: The date (by component) to fetch the `Leaderboard` for. Leaderboards are fetched by month, so specifying the year and month in the components are necessary to receive the correct leaderboard. Defaults to fetching the current leaderboard.

{% tabs %}
{% tab title="Swift" %}

```swift
let service = LeaderboardService()
service.fetch(dateComponents: DateComponents(year, month)) { result in
    switch result {
    case .success:
        // fetch succesful
        break
    default:
        // error
    }
})
```

{% endtab %}

{% tab title="Kotlin" %}

```kotlin
val service = LeaderboardService()
val dataComponents = DataComponents(Date())
val filters = Set<Filter>

service.fetch(dataComponents, filters) { result: Result<Content?>? ->
    if (result?.value == null || result.throwable != null) {
        // failure
    } else {
        // Success
        val content = result.value
        completionHandler(content)
    }
})
```

{% endtab %}
{% endtabs %}