Adding the Notification Plugin
Add the BreezSDKLiquid
cocoapod to your iOS Podfile, with the target NotificationService
. You can add any other dependencies your require here also, for example KeychainAccess
to read the saved mnemonic from the keychain.
target 'NotificationService' do
pod 'BreezSDKLiquid'
pod 'KeychainAccess'
end
Once added to the Podfile, run pod install
to install the dependencies.
More installation methods, including with the Swift Package Manager, can be found in the breez-sdk-liquid-swift repository.
Integrate the Notification Plugin
You're ready to add some Swift code to implement the Notification Plugin in your NotificationService target. In Xcode, in the NotificationService
folder, open the Swift file named NotificationService.swift
.
This Swift file should implement the Notification Plugin's SDKNotificationService
class. The SDKNotificationService
class handles the incoming notification content and processes the event. To properly implement this class, the NotificationService needs to override at least the getConnectRequest
function. The getConnectRequest
function is called by the SDKNotificationService
to get a ConnectRequest
which contains the data necessary to connect to the SDK. This data includes the Config
with its workingDir
and the mnemonic.
Developer note
When using the Notification Plugin on iOS, it is important to note that theConfig
workingDir
needs to be set to the app group's shared directory in both the NotificationService
target and in the main application target, whether that is a Swift, Flutter or React Native based application.
Developer note
When accessing the Keychain using the Keychain Group, theAppIdentifierPrefix
needs to be prepended to the configured identifier, like <TEAM_ID>.com.example.SharedKeychain
. This Keychain Group needs to be used in the main application target as the accessGroup when you want to store anything on the keychain that later needs to be accessed by the notification service.
import UserNotifications
import KeychainAccess
import BreezSDKLiquid
fileprivate let logger = OSLog(
subsystem: Bundle.main.bundleIdentifier!,
category: "NotificationService"
)
fileprivate let appGroup = "group.com.example.application"
fileprivate let keychainGroup = "A352BFE4OR.com.example.SharedKeychain"
fileprivate let accountMnemonic: String = "BREEZ_SDK_LIQUID_SEED_MNEMONIC"
class NotificationService: SDKNotificationService {
// Override the `getConnectRequest` function
override func getConnectRequest() -> ConnectRequest? {
var config = defaultConfig(network: LiquidNetwork.mainnet)
// Set the workingDir as the app group's shared directory,
// this should be the same directory as the main application uses
config.workingDir = FileManager
.default.containerURL(forSecurityApplicationGroupIdentifier: appGroup)!
.appendingPathComponent("breezSdkLiquid", isDirectory: true)
.path
// Get the mnemonic from the shared keychain using the same
// service name as the main application
let service = Bundle.main.bundleIdentifier!.replacingOccurrences(of: ".NotificationService", with: "")
let keychain = Keychain(service: service, accessGroup: keychainGroup)
guard let mnemonic = try? keychain.getString(accountMnemonic) else {
os_log(.error, "Mnemonic not found")
return nil
}
return ConnectRequest(config: config, mnemonic: mnemonic)
}
}
Reference implementation
For a complete reference, see how we implemented it in misty-breez wallet: NotificationService.swift.