class-256.js

class-256.js is a less than 256 byte JavaScript classical inheritance pattern library (221 bytes minified or 363 bytes minified with UMD pattern).
Originally based on augment and extend (repository no longer exists).

Features

• OOP style declaration
• Constructor methods (optional - if you don't provide one, the parent's constructor will be called upon instantiation)
• Working instanceof
• Supports public and private/privileged methods, public and private static properties
• Non-overridden public properties/methods defined in parent naturally accessible
• Overridden public methods defined in parent accessible through parent parameter

Basic usage

var HelloWorld = Class.extend(function() { // default name of .extend() can be changed via constant
	this.greeting = 'Hello '; // public property

	var world = 'World!'; // private static property

	this.constructor = function(greeting) { // default name of .constructor() can be changed via constant
		if (typeof greeting != 'undefined') {
			this.greeting = greeting;
		}
	};

	this.say = function() { // public method
		return privileged.call(this);
	};

	function privileged() { // private/privileged method
		return this.greeting + world;
	}

	this.setWorld = function(newWorld) {
		world = newWorld;
	};

	this.getWorld = function() {
		return world;
	};
});

var helloWorld = new HelloWorld();

assert.equal(helloWorld.say(), 'Hello World!');
assert.instanceOf(helloWorld, HelloWorld);

var hiWorld = new HelloWorld('Hi ');

assert.equal(hiWorld.say(), 'Hi World!');
assert.instanceOf(hiWorld, HelloWorld);

helloWorld.setWorld('Earth!');
assert.equal(helloWorld.say(), 'Hello Earth!');
assert.equal(hiWorld.say(), 'Hi Earth!'); // Because 'world' is a static property

Extending

function isNonEmptyString(value) {
	return typeof value == 'string' && value.length > 0;
}

var Base = Class.extend(function() {
	this.name = '';

	this.constructor = function(name) {
		this.name = name;
	};

	// check name
	this.isValid = function() {
		return isNonEmptyString(this.name);
	};
});


var Extended = Base.extend(function(parent) {
	this.address = '';

	this.constructor = function(name, address) {
		parent.constructor.call(this, name); // call parent constructor
		// could be also written as: this.name = name;

		this.address = address;
	};

	// check name and address
	this.isValid = function() {
		return parent.isValid.call(this) && isNonEmptyString(this.address);
		// could be also written as: return isNonEmptyString(this.name) && isNonEmptyString(this.address);
	};
});

var emptyExample = new Extended(null, null);

assert.isFalse(emptyExample.isValid());

var nameExample = new Extended('John', null);

assert.isFalse(nameExample.isValid());

var addressExample = new Extended(null, 'London');

assert.isFalse(addressExample.isValid());

var validExample = new Extended('John', 'London');

assert.isTrue(validExample.isValid());

For more examples see test/test.js.

Installation

NPM

npm install class-256.js

Bower

bower install class-256.js

Browser

<script src="https://github.com/koffeine/class-256.js/blob/master/dist/class.umd.min.js"></script>

Files

| UMD | Minified | File | |:----|:---------|:----------------------------------------------------------------------------------------------------| | ✓ | ✓ | dist/class.umd.min.js | | ✓ | | dist/class.umd.js |

Develop

Requirements

Building requires NodeJS version 6.0.0 or later.

Set up

npm install

Build

Running the following command will start Gulp, which will run ESLint, create the UMD version, run Mocha/Chai tests and run UglifyJS:

gulp

License

Copyright © 2015-2018 Kornél Horváth

Licensed under the MIT License.