Weakness

Kotlin weak properties

Introduction

One of the unwanted features of classes is that you cannot add additional data in an object without declaring a field in its class.

This feature is unwanted when making a library since a library might need to tag user define objects to process them automagically without the user knowing how or implement extra interfaces.

This feature is inescapable. Or, is it?

This library bypasses this feature by storing the data in a global instance. A Map or more specifically a WeakHashMap to deal with garbage collection.

Additionally, this library adds more utilities to take more advantage from this library in kotlin.

Install

The main way of installing this library is using jitpack.io

repositories {
    // ...
    mavenCentral()
    maven { url = uri("https://jitpack.io") }
}

dependencies {
    // Replace TAG with the desired version
    implementation("org.cufy:weakness:TAG")
}

Setup and Usage

The following is basic usage example:

class Entity

var Entity.name: String by weak()

Or you can define your closed-scoped properties

class Entity

val MyWeakness = Weakness()

var Entity.closedName: String by weak(MyWeakness, "name")

So far, we only declared lateinit weak properties. To declare a lazily initialized property you need to pass a default value factory to the weak function.

class Entity

var Entity.name: String by weak { "default value" }