dataExtractionRules in Android12

Question

When we don't want to maintain SharedPreferences or any backup file, we can just set android:allowBackup="false" in AndroidManifest.xml.
But android:allowBackup="false" is deprecated in Android12. Even though it's deprecated, we can still keep using it just for the cloud-based backup. for example, if we're using SharedPreferences, after deleting our app and re-installing it, the SharedPreferences are gone. You can find the information from here.

So, What i want to know is about D2D. In Android12, The android system automatically send files from old device to new device(D2D). I want to stop the system from sending files(like SharedPreferences) automactically by default. So, I have to make dataExtractionRules which files include or not.

What i want to do is to exclude all files. it means that i can just transfer the app to new device but there are no data or cache like i just downloaded a new app. So, How can i write dataExtractionRules to acheive it?

please check the following code what i did.

data_exctration_rules.xml

<?xml version="1.0" encoding="utf-8"?>
<data-extraction-rules>

<!-- <cloud-backup> I don't write cloud-backups in here
 because i can still use android:allowBackup="false" </cloud-backup> -->
    
    <device-transfer>
        <exclude domain="root" path="where?" />
        <exclude domain="file" path="where?" />
        <exclude domain="database" path="where?" />
        <exclude domain="sharedpref" path="com.google.android.gms.appid.xml" />
        <exclude domain="sharedpref" path="user_pref.xml" />
        <!-- <exclude domain="external" path="where?" /> -->
    </device-transfer>
</data-extraction-rules>

Q1. Can i use several <exclude domain="sharedpref">? because i have 4 files of SharedPrefereces.

Q2. How exactly should I write down the path? ex) "data/data/com.myapp/sharedpref/user_pref.xml" or just "user_pref.xml"

Q3. What does "<exclude domain="root" path="" />" mean? does root mean my app? if it is, Don't I need to write another file(like file, database, sharedpref, external etc)?

Answer 1

You should read docs.

The brief answers about your questions.

Q1. Can i use several <exclude domain="sharedpref">? because i have 4 files of SharedPrefereces.

Yes, you can. You should indicate several declaration or just one with ./ path attribute(all files in this directory).

Q2. How exactly should I write down the path? ex) "data/data/com.myapp/sharedpref/user_pref.xml" or just "user_pref.xml"

You can check your shared preferences xml file name in device file explorer of Android Studio tool.

Just user_pref.xml the domain automatically generate a path for the matched filename.

Q3. What does <exclude domain="root" path="" /> mean? does root mean my app? if it is, Don't I need to write another file(like file, database, sharedpref, external etc)?

I think, you need just root domain and ./ path for ignoring all file backup.

But I recommended like that

<?xml version="1.0" encoding="utf-8"?>
<data-extraction-rules>
    <cloud-backup>
        <exclude
            domain="root"
            path="./" />
        <exclude
            domain="file"
            path="./" />
        <exclude
            domain="database"
            path="." />
        <exclude
            domain="sharedpref"
            path="." />
        <exclude
            domain="external"
            path="./" />
    </cloud-backup>
    <device-transfer>
        <exclude
            domain="root"
            path="./" />
        <exclude
            domain="file"
            path="./" />
        <exclude
            domain="database"
            path="." />
        <exclude
            domain="sharedpref"
            path="." />
        <exclude
            domain="external"
            path="./" />
    </device-transfer>
</data-extraction-rules>

Figure 1)