kotlin-android-persisted-vars

var timesStarted by persisted.Int(0) - Easily persisting vars backed by Android's SharedPreferences.

This is not a library. It's just an implementation example.

The issue

Sometimes we have some SharedPreferences-backed variables, doing something like:

var x: Int
    get() = sharedPrefs.getInt("x", 0)  
    set(value) {  
        sharedPrefs.edit { putInt("x", value) }  
    }

We can reduce the boilerplate and simplify all of those cases to, for example:

var x by persisted.Int(0)

By using Kotlin's delegates and a bit of reflection.