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enum deserialization of missing values to null

See original GitHub issue

My domain class has one field as an enum.

Recently I decided to change the enum values for a better readeability. But know when trying to load users from firebase i get the exception.

Giveaway giv = ds.getValue(Giveaway.class);

Process: com.tomatedigital.instagramgiveawaywinner, PID: 21593
       com.google.firebase.database.DatabaseException: Could not find enum value of com.tomatedigital.giveawaymaster.domain.CommentListType for value "COMMON_NAMES"
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToEnum(com.google.firebase:firebase-database@@19.2.1:314)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.1:229)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToType(com.google.firebase:firebase-database@@19.2.1:178)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.access$100(com.google.firebase:firebase-database@@19.2.1:47)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.1:592)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.1:562)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(com.google.firebase:firebase-database@@19.2.1:432)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.1:231)
           at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(com.google.firebase:firebase-database@@19.2.1:79)
           at com.google.firebase.database.DataSnapshot.getValue(com.google.firebase:firebase-database@@19.2.1:203)
           at com.tomatedigital.giveawaymaster.firabase.LoginValueEventListener$3.onDataChange(LoginValueEventListener.java:178)
           at com.google.firebase.database.Query$1.onDataChange(com.google.firebase:firebase-database@@19.2.1:179)
           at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@19.2.1:75)
           at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@19.2.1:63)
           at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@19.2.1:55)
           at android.os.Handler.handleCallback(Handler.java:883)
           at android.os.Handler.dispatchMessage(Handler.java:100)
           at android.os.Looper.loop(Looper.java:214)
           at android.app.ActivityThread.main(ActivityThread.java:7356)
           at java.lang.reflect.Method.invoke(Native Method)
           at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

COMMON_NAMES was changed to something else.

I completely understand the reason of this exception… my question is “are there any workaround?”…

I wish i could tell firebase to map unexisting enum values to null or any value, so then i could manually deal with them…

Is a very complicated restriction to throw a fatal exception like this on deserialization for a missing value… it means that ALL APPS RUNNING FIREBASE WONT BE ALLOWED TO REMOVE ENUM VALUES FOREVER…

Issue Analytics

State:
Created 3 years ago
Comments:12 (7 by maintainers)

Top GitHub Comments

1reaction

dconeybecommented, Apr 12, 2022

@risalfajar That is a great idea. If we ever implement this feature then we will likely do just that for Kotlin if it’s technically possible.

0reactions

risalfajarcommented, Apr 8, 2022

I am using Kotlin and I’ve experienced this unknown enum problem. However, in my case, it’s a little bit different since I’m using Kotlin.

I have a simple data class that contains an enum

data class User(
    val authority: Authority = Authority.USER // default value provided
)

enum class Authority {
    USER, SUPER_ADMIN
}

Let’s say that in the DB there’s a User with an authority of GENERAL_ADMIN, it will lead to a crash since it’s unknown to the app.

I think instead of throwing an exception and causing a crash, the serializer should use the default value provided instead.

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