Android Kotlin firebase.database.DatabaseException: No properties to serialize found on class

Question

I have followed the advice of other SO solution: 1. Make my class Serializeable 2. Have a default constructor for Firebase 3. Update my proguard rules (Not sure about this o

Answer 1

Solved, even in Kotlin it seems the variables had to be explicitly Public.

import java.io.Serializable

/**
 * Created by fyi2 on 2/21/18.
 */
class User :Serializable {
    public var displayName:String=""
    public var email:String=""
    public  var photoUrl:String=""
    public var userId:String=""

    constructor() {}

    constructor(displayName: String, email: String, photoUrl: String, userId: String) {
        this.displayName = displayName
        this.email = email
        this.photoUrl = photoUrl
        this.userId = userId
    }

}

Once that was modified, the rest worked as is.

Answer 2

you can easily use a data class, it already comes with an empty constructor ect.

@IgnoreExtraProperties
data class User(
    var displayName: String? = null,
    var email: String? = null,
    var photoUrl : String? = null,
    var userId: String? = null
)

Answer 3

If you got the issue on release apk then Do like this in your proguard file

    -keepattributes Signature

    -keepclassmembers class com.yourcompany.models.** {
      *;
    }