Initial values for PreferenceScreen/PreferenceFragment when using PreferenceDataStore

user_2212458 0
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I'm implementing a preference screen which is an XML file with the PreferenceScreen tag inflated in a PreferenceFragment. Typically this is backed by SharedPreferences, however for my particular situation we are swapping the SharedPreferences for a custom PreferenceDataStore for some of the preferences.

In the Fragment onCreate method we get the individual preferences and hook them to the PreferenceDataStore.

SwitchPreference pref = (SwitchPreference) findPreference("my_boolean_preference");
pref.setPreferenceDataStore(dataStore);

This works fine except that the current value is ignored when the screen is first displayed. How can I get the value when the screen is first displayed to be correct. Should I put the above code somewhere other than onCreate? Is there some refresh or rebind I should call?

Currently I'm working around the issue by manually setting the value right after calling setPreferenceDataStore.

pref.setChecked(dataStore.getBoolean("my_boolean_preference", false));
sharedpreferences android
1 Answers

From here:

Note: If you set a data store for a Preference after the Preference is attached to the hierarchy, the initial value for the Preference is not propagated again.

You can do this:

class MyFragment : PreferenceFragmentCompat() {

    override fun onCreatePreferences(savedInstanceState: Bundle, rootKey: String) {
        super.onCreatePreferences(savedInstanceState, rootKey)

        // set dataStore before calling setPreferencesFromResource()
        preferenceManager?.preferenceDataStore = dataStore

        setPreferencesFromResource(R.xml.prefs_main, rootKey)
        ...
    }
}
user_51727150
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