Core

The core library provides the RxSharedPreferences class that contains APIs to get typed Preference objects, which represent the preferences stored in the Android SharedPreferences.

Getting the dependency

implementation "com.frybits.rx.preferences:core:2.0.1"

Usage

Creating RxSharedPreferences

Kotlin Java

val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)
val rxSharedPreferences = sharedPreferences.asRxSharedPreferences()

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
RxSharedPreferences rxSharedPreferences = RxSharedPreferences.create(sharedPreferences);

Basic usage of preferences

Kotlin Java

// Using a string preference
val usernamePref: Preference<String?> = rxSharedPreferences.getString("username") // Default value optional

println(usernamePref.value) // null

usernamePref.value = "bob"

println(usernamePref.value) // "bob"

// Using a string prefrence
Preference<String> usernamePref = rxSharedPreferences.getString("username"); // Default value optional

System.out.println(usernamePref.getValue()); // null

usernamePref.setValue("bob");

System.out.println(usernamePref.getValue()); // "bob"

Using Enums

Kotlin Java

enum class Cats {
    TABBY,
    BLACK,
    ORANGE
}
val catsPref: Preference<Cats> = rxSharedPreferences.getEnum("cats", Cats.TABBY)

println(catsPref.value) // "TABBY"

catsPref.value = Cats.ORANGE

println(catsPref.value) // "ORANGE"

enum Cats {
    TABBY,
    BLACK,
    ORANGE
}
Preference<Cats> catsPref = rxSharedPreferences.getEnum("cats", Cats.TABBY, Cats.class);

System.out.println(catsPref.getValue()); // "TABBY"

catsPref.setValue(Cats.ORANGE);

System.out.println(catsPref.getValue()); // "ORANGE"

Using custom types

Kotlin Java

@Serializable
data class Foobar(val someString: String = "", val someInt: Int = 0)

// Create the converter
val converter = object : Converter<Foobar?> {
    override fun deserialize(serialized: String?): Foobar? {
        return serialized?.let { Json.decodeFromString<Foobar>(it) }
    }

    override fun serialize(value: Foobar?): String? {
        return value?.let { Json.encodeToString(it) }
    }
}

val foobarPref: Preference<Foobar?> = rxSharedPreferences.getObject("foobar", null, converter)

println(foobarPref.value) // null

foobarPref.value = Foobar("str", 42)

println(foobarPref.value) // "Foobar(someString=str, someNum=42)"

public static class Foobar {
    final String someString;
    final int someInt;

    public Foobar() {
        someString = "";
        someInt = 0;
    }

    public Foobar(String someString, int someInt) {
        this.someString = someString;
        this.someInt = someInt;
    }

    @NonNull
    @Override
    public String toString() {
        return "Foobar(someString=" + someString + ", someInt=" + someInt + ")";
    }
}

// Assuming Gson usage in Java
Gson gson = new Gson();

// Create the converter
Preference.Converter<Foobar> converter = new Preference.Converter<Foobar>() {
    @Nullable
    @Override
    public Foobar deserialize(@Nullable String serialized) {
        if (serialized == null) {
            return new Foobar();
        }
        return gson.fromJson(serialized, Foobar.class);
    }

    @Nullable
    @Override
    public String serialize(@Nullable Foobar value) {
        if (value == null) {
            return null;
        }
        return gson.toJson(value);
    }
};
Preference<Foobar> foobarPref = rxSharedPreferences.getObject("foobar", null, converter);

System.out.println(foobarPref.getValue()); // null

foobarPref.setValue(new Foobar("str", 42));

System.out.println(foobarPref.getValue()); // "Foobar(someString=str, someInt=42)"

Clearing the preferences

Kotlin Java

// Using a string preference
val usernamePref: Preference<String?> = rxSharedPreferences.getString("username", "bob") // Default value optional

println(usernamePref.isSet) // false
println(usernamePref.defaultValue) // "bob"
println(usernamePref.value) // "bob"

usernamePref.value = "domokun"

println(usernamePref.isSet) // true
println(usernamePref.defaultValue) // "bob"
println(usernamePref.value) // "domokun"

// Clears this preference
usernamePref.delete()
// or to clear everything
// rxSharedPreferences.clear() 

println(usernamePref.isSet) // false
println(usernamePref.defaultValue) // "bob"
println(usernamePref.value) // "bob"

// Using a string prefrence
Preference<String> usernamePref = rxSharedPreferences.getString("username", "bob"); // Default value optional

System.out.println(usernamePref.isSet()); // false
System.out.println(usernamePref.getDefaultValue()); // "bob"
System.out.println(usernamePref.getValue()); // "bob"

usernamePref.setValue("domokun");

System.out.println(usernamePref.isSet()); // true
System.out.println(usernamePref.getDefaultValue()); // "bob"
System.out.println(usernamePref.getValue()); // "domokun"

// Clears this preference
usernamePref.delete();
// or to clear everything
// rxSharedPreferences.clear();

System.out.println(usernamePref.isSet()); // false
System.out.println(usernamePref.getDefaultValue()); // "bob"
System.out.println(usernamePref.getValue()); // "bob"