Integrate CallKit into the UI Library

The Azure Communication Services UI Library provides out-of-the-box support for CallKit. Developers can provide their own configuration for CallKit to be used for the UI Library.

In this article, you learn how to set up CallKit correctly by using the UI Library in your application.

Prerequisites

• An Azure account with an active subscription. Create an account for free.
• A deployed Communication Services resource. Create a Communication Services resource.
• A user access token to enable the call client. Get a user access token.
• Optional: Completion of the QuickStart for getting started with the UI Library composites.

For more information, see the open-source iOS UI Library and the sample application code.

Set up CallKit integration

The Azure Communication Services Calling iOS SDK supports CallKit integration. You can enable this integration in the UI Library by configuring an instance of CallCompositeCallKitOption. For more information, see Integrate with CallKit.

Specify call recipient info for outgoing calls

To specify outgoing call info, create an instance of CallKitRemoteInfo. If you don't provide CallKitRemoteInfo, the participant identifier's raw value is displayed by default.

Assign a value for displayName to customize the display name for caller. The value specified in CallKitRemoteInfo is exactly how it appears in the last-dialed call log.

Also assign the cxHandle value. It's what the application receives when the user calls back on that contact.

let cxHandle = CXHandle(type: .generic, value: "VALUE_TO_CXHANDLE")
let callKitRemoteInfo = CallKitRemoteInfo(displayName: "DISPLAY_NAME", handle: cxHandle)
callComposite.launch(..., // Locator for Azure Communication Service
                     callKitRemoteInfo: callKitRemoteInfo)

Specify call recipient info for incoming calls

To specify incoming call caller info, create an instance of CallKitOptions. If you don't provide CallKitOptions, the participant identifier's raw value is displayed by default.

Assign a value for provideRemoteInfo to customize the display name for caller. The value specified in CallKitRemoteInfo is exactly how it appears in the last-dialed call log.

Also assign the cxHandle value. It's what the application receives when the user calls back on that contact.

public func incomingCallRemoteInfo(info: Caller) -> CallKitRemoteInfo {
    let cxHandle = CXHandle(type: .generic, value: "VALUE_TO_CXHANDLE")
    var remoteInfoDisplayName = "DISPLAY_NAME"
    let callKitRemoteInfo = CallKitRemoteInfo(displayName: remoteInfoDisplayName,
                                                            handle: cxHandle)
    return callKitRemoteInfo
}

Configure providers

As required, provide a CXProviderConfiguration instance to CallKitOptions. For more information, see the Apple developer documentation about CXProviderConfiguration.

let providerConfig = CXProviderConfiguration()
providerConfig.supportsVideo = true
providerConfig.maximumCallGroups = 1
providerConfig.maximumCallsPerCallGroup = 1
providerConfig.includesCallsInRecents = true
providerConfig.supportedHandleTypes = [.phoneNumber, .generic]

Configure an audio session

Configure an audio session to be called before placing or accepting incoming call and before resuming a call that's on hold. For more information, see the Apple developer documentation about AVAudioSession.

public func configureAudioSession() -> Error? {
    let audioSession = AVAudioSession.sharedInstance()
    let options: AVAudioSession.CategoryOptions = .allowBluetooth
    var configError: Error?
    do {
        try audioSession.setCategory(.playAndRecord)
    } catch {
        configError = error
    }
    return configError
}

Enable CallKit

To enable CallKit, create an instance of CallKitOptions and provide it to callCompositeOptions.

let isCallHoldSupported = true // enable call hold (default is true)
let callKitOptions = CallKitOptions(
    providerConfig: providerConfig,
    isCallHoldSupported: isCallHoldSupported,
    provideRemoteInfo: provideRemoteInfo,
    configureAudioSession: configureAudioSession
)

let options = CallCompositeOptions(
    ..., // Other options for Azure Communication Service
    callKitOptions: callKitOptions
)

Hold and Resume API for CallKit integrated in application

For CallKit integrated in application use hold and resume to manage call state.

    callComposite.hold() { result in
        switch result {
            case .success:
                // success
            case .failure(let error):
                // failure
        }
    }

    callComposite.resume() { result in
        switch result {
            case .success:
                // success
            case .failure(let error):
                // failure
        }
    }

Next steps

• Learn more about the UI Library