es-class

    2.1.1 • Public • Published

    es-class build status

    A future proof, backward compatible, JavaScript class utility.

    • ES6 and ES7 friendly, through semantic extends and constructor plus other features
    • ES5 natively compatible granting that what you write is what you get
    • ES3 backward compatible, thanks to common minifiers that will make production code safe

    Feel free to test all features related to this project, and please come back if your browser is not green.

    via npm

    npm install es-class It is suggested to install this globally as it's a very small script.

    via cdn

    Many thanks to cdnjs for hosting this script. Following an example on how to include it.

    <script
      src="//cdnjs.cloudflare.com/ajax/libs/es-class/1.2.2/es-class.js"
    >/* ES-Class */</script> 

    Compatibility

    Following a list of tested browsers split in Desktop and Mobile, plus a list of server/micro-controller side supported engines.

    Desktop

    • IE 6 or greater
    • Firefox 3 or greater
    • Chrome
    • Safari
    • Opera

    Mobile

    • Android 2 or greater
    • iOS 5 or greater
    • UC Browser and UC Mini
    • IE9 Mobile or greater
    • Opera Mini and Mobile
    • Blackberry OS 7 and OS 10
    • Kindle Fire
    • Ubuntu Phone
    • Bada
    • Xpress
    • webOS

    Others (tested)

    • Espruino Pico
    • MIPS version of node for Arduino Yun
    • node.js 0.6+ and io.js every (so Raspberry PI and every other with node.js)
    • Duktape and Nashorn

    If you actually know a hybrid (like Espruino) or ES3+ engine that does not work, please file a bug, thank you!

    Features

    All features explained in the dedicated page.

    Following a summary:

    • constructor to optionally define the implicit initializer per each instance
    • extends to optionally define a class or an object to inherit from
    • super to shortcut super methods invocation
    • with to attach lightweight traits / mixins enabling composition behind optional initializers per each mixin. Compatible with universal-mixin since version 1.3.0
    • static to define public static class constants, inherited if extended, without ever polluting the prototype
    • implements to perform light checks over expected implementations and warn eventually when something is missing

    Features Example

    This is an example of what's possible:

    var Engineer = Class({
      extends: Person,
      with: [
        eventEmitter,
        growingEachYear,
        carrierPath
      ],
      implements: [
        iWorker
      ],
      static: {
        SOFTWARE: 0,
        CONSTRUCTIONS: 1
      },
      constructor: function (name, age, type) {
        this.super(name, age);
        this.type = type;
      }
    });
     
    var me = new Engineer(
      'Mr. Andrea Giammarchi',
      36,
      Engineer.SOFTWARE
    );
     
    me instanceof Person; // true
    me.type;              // Engineer.SOFTWARE
     
    me.emit('work:start', {
      tasks: ['do this', 'do that']
    });

    ES6 Ready

    Using Babel it is possible to make your code directly compatible down to ES5 or even ES3 without loosing the ability to debug in every platform without needing source-map. What you see is basically what you get.

    // how you would write in native ES6
    class B extends A {
      method(x, y) {
        return super.method(x, y);
      }
      get value() {
        return super.value;
      }
      set value(value) {
        super.value = value;
      }
    }
     
    // how you would write in es-class
    var B = Class({ extends: A,
      method(x, y) {
        return this.super(x, y);
      },
      get value() {
        return this.super();
      },
      set value(value) {
        return this.super(value);
      }
    });

    A simple call to babel --whitelist=es6.arrowFunctions,es6.properties.shorthand f.js and the output will be way cleaner than any automation produced by the same transpiler.

    Your output will be more readable and also probably faster at execution time.

    ES7 Ready

    Looking at the future, grouped static properties and lightweight traits are also in, giving the ability to compose classes through eventual traits initialization without being on the way after class definition.

    var wheels = {
      init: function () {
        if (this instanceof Car) {
          this.frontWheels = 2;
          this.rearWheels = 2;
        } else {
          this.frontWheels = 1;
          this.rearWheels =
            this instanceof Tricycle ? 2 : 1;
        }
      },
      turn: function (where) {
        console.log('turning ' + where);
      }
    };
     
    var engine = {
      hp: 120
    };
     
    var Car = Class({
      with: [
        wheels,
        engine
      ]
    });
     
    var c = new Car;
    c.turn('left'); // trning left
    c.hp;           // 80

    Which File ?

    You can also simply npm install -g es-class and use var Class = require('es-class'); whenever you need it.

    License

    MIT Style License

    Install

    npm i es-class

    DownloadsWeekly Downloads

    13,667

    Version

    2.1.1

    License

    MIT

    Last publish

    Collaborators

    • webreflection