Kotlin Android Library, that makes preference usage simple and fun.

KotlinPreferences now have a brother.

With KotlinPreferences, you can define different preference fields this way:

var SharedPreferences.canEatPie: Boolean by bindToPreferenceField(true)

And use it like any SharedPreference property:

preferences.canEatPie = true
if(preferences.canEatPie) //...

There are different ways to define this properties. Here are some possibilities: (see full example here and usage here)

With default value:

var SharedPreferences.canEatPie: Boolean by bindToPreferenceField(true)
var SharedPreferences.allPieInTheWorld: Long by bindToPreferenceField(0)

Nullable:

var SharedPreferences.monstersKilled: Int? by bindToPreferenceFieldNullable()
var SharedPreferences.experience: Float? by bindToPreferenceFieldNullable()
var SharedPreferences.className: String? by bindToPreferenceFieldNullable()

Can also keep other objects:

var SharedPreferences.character: Character by bindToPreferenceFieldNullable()
var SharedPreferences.savedGame: Game? by bindToPreferenceFieldNullable()

Node that this objects are serialized do string using Gson. If they include some, types that needs some serializers, then you need to set gson with converters. Instructions here.

Also keys can be specyfied: (this is important to make values immtuable to property name in case of changes in the app)

var SharedPreferences.monstersKilled: Int? by bindToPreferenceFieldNullable("MonstersKilledKey")
var SharedPreferences.allPieInTheWorld: Long by bindToPreferenceField(0, "AllPieKey")

To add KotlinPreferences to the project, add in build.gradle file:

dependencies {
    compile 'com.github.marcinmoskala:kotlinpreferences:1.00'
}

And while library is located on JitPack, remember to add on module build.gradle (unless you already have it):

repositories {
    maven { url 'https://jitpack.io' }
}

Copyright 2017 Marcin Moskała
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
   https://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.