Kotlin Sharedpreferences

LocalData.kt

import android.content.Context
import android.content.SharedPreferences
import android.util.Log


private const val SHAREDPREF = "shared"
private const val FIRST_TIME = "firstime"

class LocalData(val context: Context) {

    private val sharedPreferences: SharedPreferences
        get() {
            return context.applicationContext.getSharedPreferences(SHAREDPREF, Context.MODE_PRIVATE)
        }
    private val editor: SharedPreferences.Editor
        get() {
            return sharedPreferences.edit()
        }
    private val firstTimeSharedPreferences: SharedPreferences
        get() {
            return context.applicationContext.getSharedPreferences(FIRST_TIME, Context.MODE_PRIVATE)
        }


    /**
     * Save a key value pair to shared pref
     * @param title
     * @param content
     */
    fun write(title: String, content: String?) {
        editor.putString(title, content).apply()
    }

    /**
     * Save a key value pair to shared pref
     * @param title
     * @param content
     */
    fun write(title: String, content: Boolean) {
        editor.putBoolean(title, content).apply()
    }


    /**
     * Read value from shared prefs
     * @param title
     * @return
     */
    fun read(title: String): String? {
        return sharedPreferences.getString(title, null)
    }

    /**
     * Read value from shared prefs
     * @param title
     * @return
     */
    fun read(title: String, def: String): String {
        return sharedPreferences.getString(title, def)
    }


    /**
     * Read value from shared prefs
     * @param title
     * @return
     * @throws NullPointerException
     */
    fun read(title: String, def: Boolean): Boolean {
        val sharedPreferences = context.applicationContext.getSharedPreferences(SHAREDPREF, Context.MODE_PRIVATE)
        return sharedPreferences.getBoolean(title, def)
    }

   
    /**
     * Returns true for specific action only once
     * @param action String key for action
     * @return boolean true if not called before, false afterwards
     */
    infix fun isFirsTimeOf(action: String): Boolean {
        if (firstTimeSharedPreferences.getBoolean(action, true)) {
            firstTimeSharedPreferences.edit().putBoolean(action, false).apply()
            return true
        }
        return false
    }

    /**
     * Remove all data associated with the SharedPref key
     */
    fun burnEverything() {
        context.applicationContext.getSharedPreferences(SHAREDPREF, Context.MODE_PRIVATE).edit().clear().apply()
        context.applicationContext.getSharedPreferences(FIRST_TIME, Context.MODE_PRIVATE).edit().clear().apply()
    }

    companion object {
        fun with(context: Context): LocalData{
            return LocalData(context)
        }
        //To use it like LocalData.with(context).read("data")
    }
}