Preferance Helper

PreferenceHelper.kt

package com.vk.android.helper

import android.content.Context
import android.content.SharedPreferences

class PreferenceHelper private constructor(context: Context) {

    private val sharedPref: SharedPreferences = context.getSharedPreferences(context.packageName + ".PREFERENCE", Context.MODE_PRIVATE)


    companion object {
        private var instance: PreferenceHelper? = null
        private const val SERVER_TOKEN = "server_token"
        private const val USER_ID = "user_id"
        private const val DEVICE_TOKEN = "device_token"

        fun getInstance(context: Context) = instance ?: synchronized(this) {
            instance ?: PreferenceHelper(context).also { instance = it }
        }
    }

    var severToken: String?
        get() = sharedPref.getString(SERVER_TOKEN, "")
        set(value) {
            val edit = sharedPref.edit()
            edit.putString(SERVER_TOKEN, value)
            edit.apply()
        }

    var userId: String?
        get() = sharedPref.getString(USER_ID, "")
        set(value) {
            val edit = sharedPref.edit()
            edit.putString(USER_ID, value)
            edit.apply()
        }

    var deviceToken: String?
        get() = sharedPref.getString(DEVICE_TOKEN, "")
        set(value) {
            val edit = sharedPref.edit()
            edit.putString(DEVICE_TOKEN, value)
            edit.apply()
        }

    fun logOut() {
        severToken = ""
        userId = ""
    }
}