Android Studio: Kotlin - How to read and edit DataStore Values in another Activity

Question

I am currently building an app that will have a passcode to enter at launch. I am storing this passcode value in datastore as using the room API for just one value seems silly. Thinking ahead, I know two activities will need to access passcode information: the launching activity and the settings activity to change the passcode. The problem with this is I see no way of accessing the datastore again after creation. I would like advice on how to proceed with accessing this information in multiple places.

I do have some ideas on how to get around this problem however as there does not seem to be a getDataStore function in existance.

1. Create a viewModel to contain passcode information so that datastore can act like a singleton class.(Problem: viewModels can not be shared across activities as answered here)

2. Create a singleton class that contains a dataStore instance in a companion object. (Problem: An instance of this singleton class created in activity is not guaranteed to maintain companion object values, once initial instance is destroyed as answered [here] (Do companion objects remain in memory for app's lifecycle), this will be a problem when accessing later on in settings after the launching activity is destroyed with finish()) Perhaps the solution to this problem is to pass an instance of the class in a bundle to the next activity, but I doubt a dataStore object is serializable to pass via bundle.

3. Multi-Process Data Store. This one admittedly boggles my mind on how to achieve. I know it runs CRUD operations via a service. I feel this is the most valid approach to my problem but I am confused by the official google guide on how to code my own version. The official google documentation is here

• The main problem with the above solution is my unfamiliarity with coding services. I am also unsure if multiple activities count as multiple process code, I possibly think so as two activities have their own lifecycles and hence processes?

Answer 1

You can use SharedPreferences to store data and access anywhere from ur app instead of Room DB.

Here is a rough dummy code -

private fun isFunctionEnabled(): Boolean {
        val prefs: SharedPreferences = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
        return prefs.getBoolean(FUNCTION_TIME_KEY, true)
    }

private fun setFunctionEnabled(value: Boolean) {
    val prefs: SharedPreferences = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
    val editor = prefs.edit()
    editor.putBoolean(FUNCTION_TIME_KEY, value)
    editor.apply()
}

Store this FUNCTION_TIME_KEY key in some constants file or somewhere

you can even create a common class where you can set and get all your shared pref values just by passing Keys. Hope this Helps