@ramumb/class

Class(function)

This is a port of the PrototypeJS class-based OOP system.

Class([superclass][, methods...]) -> Class

• superclass (Class): The optional superclass to inherit methods from.
• methods (Object): An object whose properties will be "mixed-in" to the new class. Any number of mixins can be added; later mixins take precedence.

[[Class]] creates a class and returns a constructor function for instances of the class. Calling the constructor function (typically as part of a new statement) will invoke the class's initialize method.

[[Class]] accepts two kinds of arguments. If the first argument is a [[Class]], it's used as the new class's superclass, and all its methods are inherited. Otherwise, any arguments passed are treated as objects, and their methods are copied over ("mixed in") as instance methods of the new class. In cases of method name overlap, later arguments take precedence over earlier arguments.

If a subclass overrides an instance method declared in a superclass, the subclass's method can still access the original method. To do so, declare the subclass's method as normal, but insert $super as the first argument. This makes $super available as a method for use within the function.

To extend a class after it has been defined, use [[Class#extend]].

Browser Support

• Microsoft Internet Explorer for Windows, version 6.0 and higher
• Mozilla Firefox 1.5 and higher
• Apple Safari 2.0.4 and higher
• Opera 9.25 and higher
• Chrome 1.0 and higher

Installation

npm install @ramumb/class

Usage

var Class = require('class');

// properties are directly passed to `create` method
var Person = new Class({
  initialize: function(name) {
    this.name = name;
  },
  say: function(message) {
    return this.name + ': ' + message;
  }
});
    
// when subclassing, specify the class you want to inherit from
var Pirate = new Class(Person, {
  // redefine the speak method
  say: function($super, message) {
    return $super(message) + ', yarr!';
  }
});
    
var john = new Pirate('Long John');
john.say('ahoy matey');
// -> "Long John: ahoy matey, yarr!"

Tests

npm test

Contributing

In lieu of a formal style guide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code. See the CONTRIBUTING file for more detailed information.