Using Preferences in native plugin?

Capacitor
1

Is there a native API to CapacitorJS Preferences (doc), so I can get and set values from within a native iOS plugin?

I read that silent push notifications can only trigger a native part of a CapacitorJS iOS app, so I need to move some logic to native.

2

Yes, you can add the preferences plugin as a dependency to your plugin and use the Preferences class directly from native.
That’s the same class PreferencesPlugin class uses.

3

@julio-ionic Thanks! Trying to get this to work, but I fail miserably. Too little knowledge about iOS Swift, CapacitorJS and the inter-workings, even multiple AI can’t help.

I want this function to save something to the Preferences:

import UIKit
import Capacitor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    // capacitor-plugin-silent-notifications
    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
        // debug
        print("Received by: didReceiveRemoteNotification w/ fetchCompletionHandler")

        // Perform background operation, need to create a plugin
        NotificationCenter.default.post(name: Notification.Name(rawValue: "silentNotificationReceived"), object: nil, userInfo: userInfo)

        // Save notification data using Preferences plugin
        ...

        // Give the listener a few seconds to complete, system allows for 30 - we give 25. The system will kill this after 30 seconds.
        DispatchQueue.main.asyncAfter(deadline: .now() + 25) {
            // Execute after 25 seconds
            completionHandler(.newData)
        }
    }

}

Failed attempts to import:

import @capacitor/preferences
import Preferences

This seems to work:

import CapacitorPreferences

Failed attempts on calling:

        let prefs = Preferences
        let prefs = Preferences.shared
        let prefs = CapacitorPreferences
        let prefs = CapacitorPreferences.shared
        prefs.set("receivedNotification", for: "silentNotification")

What is the right way to import and call another plugin?

There are not that many options for 3 lines of code :rofl:

4

Check the PreferencesPlugin class as it uses the Preferences object and use it the same way

5

My challenge is that the PreferencesPlugin is in the same folder. So when Swift is similar to Java, there is probably no import needed for classes in the same folder.

I want to set a value from /ios/App/App/AppDelegate.swift, so I need some kind of import. Not sure what mechanisms CapacitorJS uses with CocoaPods and CapacitorPreferences.

And I don’t want to supply a configuration, as I am assuming Preferences using a Singleton pattern, the configuration should be set by the app already, I don’t want to mess with it.

6

Currently using a workaround by accessing UserDefaults.standard directly in /ios/App/App/AppDelegate.swift:

import Foundation

private var defaults: UserDefaults {
    return UserDefaults.standard
}

let formatter = ISO8601DateFormatter()
let currentDate = Date()
let isoDateString = formatter.string(from: currentDate)
     
defaults.set("true", forKey: "CapacitorStorage.receivedSilentNotification." + isoDateString)
//print( defaults.dictionaryRepresentation().keys.filter { $0.hasPrefix("CapacitorStorage.silentNotification.") } )

With CapacitorStorage. prefix, the keys/values can be used with the regular Preferences plugin.