Kotlin - Persist MutableList on SharedPreferences

Question

I've been playing around with Kotlin for Android. I have a mutable list which is a list of objects. Now I want to persist them, but I don't know what's the best way to do it. I think it can be done with SharedPreferences but I don't know how to parse the objects to a plain format or something. The objects are actually coming from a data class, maybe that can be useful.

Thanks

Answer 1

It is very easy to persist any data within SharedPreferences. All you need to do is get Gson implementation 'com.squareup.retrofit2:converter-gson:2.3.0' and then create class you would like to persist like this:

class UserProfile {

    @SerializedName("name") var name: String = ""
    @SerializedName("email") var email: String = ""
    @SerializedName("age") var age: Int = 10

}

and finally in your SharedPreferences

fun saveUserProfile(userProfile: UserProfile?) {
            val serializedUser = gson.toJson(userProfile)
            sharedPreferences.edit().putString(USER_PROFILE, serializedUser).apply()
        }


fun readUserProfile(): UserProfile? {
            val serializedUser = sharedPreferences.getString(USER_PROFILE, null)
            return gson.fromJson(serializedUser, UserProfile::class.java)
        }