Firebase firestore variable name changed

Question

My firestore variables are saved by other names in cloud firestore. I think this is related to proguard, but I am not getting it.

Following are my username.

public String id;
public String name;
public String number;
public String profilePic;
public String shopPic;

and following is the screenshot, what is saved on firestore.

Here is some related code, which is very simple

        FirestoreUrls.get().getAccountsCollection()
                .document().set(binding.getUser()).addOnCompleteListener(new OnCompleteListener<Void>() {
            @Override
            public void onComplete(@NonNull Task<Void> task) {
                hideProgressBar();
                handleFirebaseException(getClass(), task, true);
            }
        });

Answer 1

You are experiencing this problem because you are using Proguard for security, which shuffles the code so others cannot see it right after you create the app's APK. This is also available in the case of Firebase. To solve this, please add the following lines of code in your build.gradle file:

buildTypes {
    release {
        minifyEnabled true
        shrinkResources true
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
    }
}

Then add the following rules in your project's Proguard file to prevent that behavior by replacing the package name with your own package name:

-keepattributes Signature //Global rule

-keepclassmembers class com.example.YourModelClass.** {
  *;
}

Please check the docs for more information:

• https://firebase.google.com/docs/database/android/start#proguard

Answer 2

proguard renames fields and class names to shorter ones. To prevent this you can exclude this class from proguard optimizations with "-keep class com.package.MyClass" line in proguard-android.txt file.

But IMHO instead of this you should somewhere in your code map your variables to proper strings and then send strings to cloud firestore. Because for now any refactoring in your class (renaming fields for example) may broke your firestore name matching.

UPDATE:

It looks like you can map object fileds to proper strings this way:

User user = binding.getUser()

Map<String, Object> docData = new HashMap<>();
docData.put("id", user.id);
docData.put("name", user.name);
docData.put("number", user.number);
docData.put("profilePic", user.profilePic);
docData.put("shopPic", user.shopPic);

FirestoreUrls.get().getAccountsCollection()
                .document().set(docData)...

Answer 3

• Ok, so I had the exact same problem and this is what I did to solve it.

Solution:

• Go inside you your proguard-rules.pro file and paste this:

# Add this global rule
    -keepattributes Signature
-keep class <Your class package here>.** { *; }

• The <Your class package here> can be found inside your class file:

package com.elliottsoftware.calftracker.domain.models.fireBase


//TODO THE GETTERS AND SETTERS USED BY FIREBASE ARE CASE SENSITIVE
data class FireBaseCalf(var calftag: String? = null,
                        var cowtag:String? = null,
                        var ccianumber: String? = null,
                        var sex:String? = null,
                        var details:String?=null,
                        var date: Date? = null,
                        var birthweight:String? = null,
                        var id: String? = null,

                        ) {
    // Null default values create a no-argument default constructor, which is needed
    // for deserialization from a DataSnapshot.
}

• notice the com.elliottsoftware.calftracker.domain.models.fireBase, that is what you are going to replace with <Your class package here>

• so in the end your proguard-rules.pro file will look like this:

# Add this global rule
    -keepattributes Signature

    -keep class com.elliottsoftware.calftracker.domain.models.fireBase.** { *; }