Background Handling

CometChat Calls SDK v5 — Background Handling

Overview

Keep calls alive when users press HOME or switch apps using iOS Background Modes and proper AVAudioSession configuration.

Prerequisites

• Active call session
• Background Modes capability enabled in Xcode

Implementation

1. Enable Background Modes

In Xcode: Target → Signing & Capabilities → + Capability → Background Modes. Enable:

• Audio, AirPlay, and Picture in Picture
• Voice over IP (if using CallKit)

Or in Info.plist:

<key>UIBackgroundModes</key>
<array>
    <string>audio</string>
    <string>voip</string>
</array>

2. Configure AVAudioSession

import AVFoundation

func configureAudioSession() {
    let session = AVAudioSession.sharedInstance()
    do {
        try session.setCategory(.playAndRecord, mode: .voiceChat, options: [.allowBluetooth, .defaultToSpeaker])
        try session.setActive(true)
    } catch {
        print("Audio session config failed: \(error)")
    }
}

3. Handle Background Transition

// SwiftUI
.onReceive(NotificationCenter.default.publisher(for: UIApplication.didEnterBackgroundNotification)) { _ in
    // Call continues in background with audio
    CallSession.shared.enablePictureInPictureLayout()
}

.onReceive(NotificationCenter.default.publisher(for: UIApplication.willEnterForegroundNotification)) { _ in
    CallSession.shared.disablePictureInPictureLayout()
}

Gotchas

• Background Modes must be enabled in Xcode capabilities — not just Info.plist
• voip background mode is required for CallKit integration
• audio background mode keeps the audio session alive when backgrounded
• AVAudioSession category must be set before joining the call
• iOS may terminate background audio after extended periods — CallKit helps prevent this

Sample App Reference

• CallView.swift — Call session management