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inheritor

Inheritor Build Status NPM version

Plain and simple, Inheritor is an inheritance library that emulates the inheritance pattern of backbone extend. This library functions

Install

npm install inheritor

Usage

Inheritor uses the UMD format so there are many ways of including the libary in your projects.

Global

<script src="lib/bin/inheritor.min.js"></script>
<script>
  alert(inheritor.version);
</script> 

RequireJS

define([
  'inheritor'
], function(inheritor) {
  alert(inerits.version);
});
 

Node / CommonJS

inheritor = require('inheritor');

After the library has been loaded, usage is pretty straight forward.

Emitter = require('events').EventEmmitter
 
MyEmitter = inheritor.from(Emitter, {
  someMethod: function() {
    console.log('MyEmitter Says Hi!');
  } 
});
 
MyEmitter.extend = inheritor.extend;
 
SubClassMyEmitter = MyEmitter.extend({
  someMethod: function() {
    console.log('SubClassMyEmitter Says Hi!');
 
    SubClassMyEmitter.__super.someMethod.call(this);
  }
});
 

There are a couple things to note.

  • from and extend are the same method. From takes a source as context and extends from the other provided parameters. extend uses this as its source and uses the other paramters to extend from. Adding the extend method to the MyEmitter constructor gave this context to MyEmitter.
  • __super is added to each extended constructor which directly points to the parents prototype.

Methods

from(source, [prototype [, static]])

This method will extend a source object by copying its prototype and merging it with the provided prototype. static items are added directly to the constructor and are also copied from the source and merged with the provided statics. Properties that exist in source are overwriten by properties provided.

Person = function(name) {
  this.name = name;
}
 
Person.prototype = {
  getName: function() {
    return this.name; 
  }
};
 
Employee = inheritor.from(Person, {
  work: function() {
    console.log(this.getName() + ' is doing work.');
  }
}, {
  create: function() {
    var instance = Object.create(this.prototype);
 
    instance.constructor.apply(instance, arguments);
 
    return instance
  }
});
 
Employee.create('bob').work(); // bob is doing work. 
 
john = Employee.create('john');
 
john.instanceof Employee // true 
john.instanceof Person // true 

extend([prototype [, static]])

Exactly the same as from except that the source is this. This allows you to assign the method to objects and have it work directly off them instead of having to constantly use a source.

Person = function(name) {
  this.name = name;
}
 
Person.extend = inheritor.extend;
 
Person.prototype = {
  getName: function() {
    return this.name; 
  }
};
 
Employee = Person.extend({
  work: function() {
    console.log(this.getName() + ' is doing work.');
  }
}, {
  create: function() {
    var instance = Object.create(this.prototype);
 
    instance.constructor.apply(instance, arguments);
 
    return instance
  }
});
 
EmployeeSubClass = Employee.extend({
  // more stuff 
});
 
bob = EmployeeSubClass.create('bob').work(); // bob is doing work. 
 
john = EmployeeSubClass.create('john');
 
john instanceof EmployeeSubClass // true 
john instanceof Employee // true 
john instanceof Person // true 

Building

To build the project checkout out the repository and simply use npm install and gulp.

npm install
gulp

Links

Changelog
License