Object Reflector

Table of Contents

• Features
• Examples
• Installation
• API
• FAQ

Features

• lightweight: weighing only 4kb
• minimal: there are only 4 methods
• powerful: create powerful references with minimal effort

This library lets you create powerful references between objects without affecting your code style. You can reuse and update data references between huge amounts of objects with only a few lines of code. The data between reflected objects is shared, not copied. This can save a lot memory and speed up your app performance!

Examples

The library's flow is all about parents and childrens. You define an object as a parent and then add childrens to it which inherit and share the properties you want.

Parent reflections

let a = {};
let b = {};

let reflector = new ObjectReflector({
  object: a, // our parent object
  properties: ["data"] // we want "data" to be reflected
});
reflector.createReflection(b); // b.data is now a reflection to a.data

a.data = { color: "red" }; // this updates all reflected objects
b.data; // -> { color: "red" }
a.data === b.data; // true

Child reflections

This example shows how to change a parent's data from within a child. The previous example showed us how a parent can change it's children, now we do the opposit!

let a = {};
let b = {};

let reflector = new ObjectReflector({
  object: a, // our parent object
  properties: ["data"], // we want "data" to be reflected
  enableChildReflection: true // this enables child reflections
});
reflector.createReflection(b); // b.data is now a reflection to a.data

a.data = { color: "red" }; // this updates all reflected objects
b.data; // -> { color: "red" }
b.data = { meow: 42 };  // this also updates the parent's data!
a.data; // -> { meow: 42 }
a.data === b.data; // true

Installation

Node:

npm install object-reflector

Browser:

<script type="text/javascript" src="https://raw.githubusercontent.com/maierfelix/object-reflector/master/dist/object-reflector.min.js"></script>

API

reflector = new ObjectReflector(opts)

Initializes a new ObjectReflector instance.

• opts.object The parent object to reflect from
• opts.properties Array of properties you want to reflect from the object
• opts.enableChildReflection Enables child reflections, so childs can update their parent too!

reflector.createReflection(object)

Creates a reflection to the passed in object.

reflector.unreflectChild(object)

Removes a reflection from the passed in object.

reflector.clear()

Clears all reflected childs.

FAQ

How is the performance?

Parent reflections are very fast, I use them in a 3D engine to share large amounts of meshes and textures between objects.

Child reflections are slower because they use getters/setters in the background. They are clearly fast enough for most cases, but too slow when it comes to realtime stuff or very very large sets of data.