js.class

js.class

js.class is a class library which focuses on simplifying OOP in javascript by providing rich set of tools like: mixins, inheritance, getters, setters and more.

Version 2.6.0 contains sjs macros for ES6 syntax.

###Features:

• super fast!
• small footprint, no dependency, 0.2K minimized
• works on both browser (with UMD wrapper) and node.js
• supports: inheritance, statics, constans, mixins, getters, setters
• typeOf
• build in singleton support
• ES6 syntax via sjs

Installation

###Npm

npm install js.class

###Bower

bower install js.class

API

###Usage ####Node.js

var JSClass = require('js.class');
var MyClass = JSClass({
    myMethod: function() {} //your method declaration
});

####Browser #####Normal version

<script type="text/javascript" src="dist/js.class.min.js"></script>
<script>
var MyClass = JSClass({
    myMethod: function() {} //your method declaration
});
</script>

#####AMD version:

define(['JSClass'], function (JSClass) {
    var MyClass = JSClass({
        myMethod: function() {} //your method declaration
    });
});

###JSClass ES6 syntax JSClass supports ES6 syntax thanks to sweet.js. In order to use ES6 syntax make sure you have installed sweet.js node loader and library is required as JSClass.

###Class declaration

var MyClass = JSClass({
    myMethod: function() {} //your method declaration
});

####ES6 syntax

class MyClass {}

###Constructor pattern

var MyClass = JSClass({
    create: function(param1, param2) {//this will be called with new keyword
        this.param1 = param1;
        this.param2 = param2;
    }
});

var instance = new MyClass(1,2);
console.log(instance.param1);//1
console.log(instance.param2);//2

###Getting class

var MyClass = JSClass({});
var instance = new MyClass();
console.log(instance.getClass() === MyClass);//true

####ES6 syntax

class MyClass {
  create(param1, param2) {
    this.param1 = param1;
    this.param2 = param2;
  }
}

###Getters/Setters

Getters/Setters will not work in ie < 8 due to lack of Object.defineProperty support

var MyClass = JSClass({
    create: function(param1, param2) {//this will be called with new keyword
        this.param1 = param1;
        this.param2 = param2;
    },
    get: {
        allParams = function() {
            return [param1, param2];
        },
        evenParams = function() {
            return [param1];
        },
        oddParams = function() {
            return [param2];
        }
    },
    set: {
        allParams: function(value) {
            this.param1 = value[0];
            this.param2 = value[1];
        }
    }
});
var instance = new MyClass(1,2);
console.log(instance.allParams);//[1,2]
console.log(instance.oddParams);//[2]

instance.allParams = [3,4];
console.log(instance.allParams);//[3,4]

Check tests for more examples

###Inheritance

var MyChildClass = MyClass.extend({});

####ES6 syntax

class MyChildClass extends MyClass {}

###Invoking overridden methods

var MyClass = JSClass({
    myMethod: function() {};
});
var MyChildClass = MyClass.extend({
    myMethod: function() {
        MyClass.prototype.myMethod.apply(this, arguments);
    }
});

####ES6 syntax

class MyClass {
    myMethod() {
    }
}
class MyChildClass extends MyClass {
    myMethod() {
        super();//this will call MyClass#myMethod
    }
}

###Statics and constans

Constans will not work in ie >=8 due to lack of Object.defineProperty support

Static variables can be easy defined by usage of static function, which accepts literal object.

var StaticExample = JSClass({
}).static({
    myStatic: 'myStatic'
});
console.log(StaticExample.myStatic);//myStatic
StaticExample.myStatic = 'otherValue';
console.log(StaticExample.myStatic);//otherValue

If literal object will contain a key in uppercase js-class will treat a variable as a constans:

var ConstantExample = JSClass({
}).static({
    MY_CONST: 'const'
});
console.log(ConstantExample.MY_CONST);//const
ConstantExample.MY_CONST = 'otherValue';
console.log(ConstantExample.MY_CONST);//const

###Mixins

Mixin is a class which contains a combination of methods from other classes Its really usefull strategy if you are going to follow DRY methodology. To define mixin we need to simply use mixin method:

var Pet = JSClass({
    name: function(name) {
        if (typeof name === 'undefined') {
            return this.name;
        }
        this.name = name;
    }
});
var Animal = JSClass({
    eat: function() {
        this.fed = true;
    },
    drink: function() {
        this.thirsty = false;
    }
});
var Dog = JSClass({
}).mixin(Pet, Animal);
var pluto = new Dog();
pluto.drink();
pluto.name('pluto');

console.log(pluto.name());//pluto
console.log(pluto.thirsty);//false

####ES6 syntax

class Pet {
  name(name) {
    if (typeof name === 'undefined') {
        return this.name;
    }
    this.name = name;
  }
}
class Animal {
  eat() {
    this.fed = true;
  }
  drink() {
    this.thirsty = false;
  }
}
class Dog implements Pet, Animal {}

var pluto = new Dog();
pluto.eat();
pluto.name('pluto');

console.log(pluto.name());//pluto
console.log(pluto.thirsty);//false

###Singleton In order to create singleton class set singleton property to true, eg.:

var Singleton = JSClass({
    singleton: true,
    doA: function() {
        return 'a';
    }
});

var p1 = Singleton.instance();
var p2 = Singleton.instance();

p1 === p2;//true

new Singleton();//will throw an Error

###typeOf

js.class provides handy typeOf method in every instance of class, the method allows you to determine whather object is a mixin of given class:

var pluto = new Dog();

console.log(pluto.typeOf(Dog));//true
console.log(pluto.typeOf(Animal));//true
console.log(pluto.typeOf(Pet));//true
console.log(pluto.typeOf(MyClass));//false

####ES6 syntax

var pluto = new Dog();

console.log(pluto is Dog);//true
console.log(pluto is Animal);//true
console.log(pluto is Pet);//true
console.log(pluto is MyClass);//false

Instance of support

js.class does support instanceof operator. Consider the following example:

var MyClass = JSClass({
    create: function(param1, param2) {
        this.param1 = param1;
        this.param2 = param2;
    }
});
var MyChildClass = MyClass.extend({});

var t = new MyChildClass();

console.log(t instanceof MyClass);//true
console.log(t instanceof MyChildClass);//true

####ES6 syntax

class MyClass {
  create(param1, param2) {
    this.param1 = param1;
    this.param2 = param2;
  }
}
class MyChildClass extends MyClass {

}

var t = new MyChildClass();

console.log(t instanceof MyClass);//true
console.log(t instanceof MyChildClass);//true

For Developers

###Running tests

npm install
npm test

###Running benchmarks

node ./benchmark/class-declaration.js
node ./benchmark/class-extend.js
node ./benchmark/class-mixins.js

####Class declaration benchs

node ./benchmark/class-declaration.js

class x 75,624 ops/sec ±3.23% (86 runs sampled)
js.class x 50,721 ops/sec ±9.67% (63 runs sampled)
klass x 44,743 ops/sec ±8.60% (74 runs sampled)
ee-class x 25,366 ops/sec ±6.20% (77 runs sampled)

####Class extension benchs

node ./benchmark/class-extend.js

js.class x 126,312 ops/sec ±3.57% (92 runs sampled)
class x 78,576 ops/sec ±5.05% (85 runs sampled)
klass x 59,602 ops/sec ±7.94% (76 runs sampled)
ee-class x 37,730 ops/sec ±4.70% (85 runs sampled)

####Mixins benchs

node ./benchmark/class-mixins.js

js.class x 677,574 ops/sec ±5.74% (86 runs sampled)
class x 541,828 ops/sec ±2.33% (93 runs sampled)
klass x 210,674 ops/sec ±6.61% (83 runs sampled)
ee-class x 140,770 ops/sec ±1.89% (96 runs sampled)

| Note that only js.class supports typeof method, which allows you to determine whether given object is a mixin of other object/class.

####Conclusion You may notice simple class declaration is the fastest in class library, but when it comes to more advanced oop features js.class is a good choice.

Version History

2.7.0

Added getClass method

2.6.1

Fixed bug with multiple statics

2.6.0

Added base javascript macros

2.5.3

Added UMD wrapper, organize the build folder and added npm run build to create both the build and the minified version.

2.5.2

Fix issue with set and get with multiple instances of the same Class (Thanks to fastrde)

2.5.1

Fixed constructor in factored objects

2.5.0

Added setters/getters support

2.4.1

Singleton object cannot be extended

2.4.0

Added singleton support

2.2.6

Mixin method accepts objects as well

2.2.5

Added benchmarks for libraries class, klass, ee-class

2.2.1

Fixed instance's statics. Now if you change instance's static it will be changed across all other instances of the same class

2.2.0

Removed behaviour which was copying consts/statics into children class