# Base.js

**Repository Path**: tinyset/Base.js

## Basic Information

- **Project Name**: Base.js
- **Description**: Github clone of Dean Edwards' latest Base.js
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2015-05-23
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

From http://dean.edwards.name/weblog/2006/03/base/

The Base Class
==============

I’ve created a JavaScript class (Base.js) that I hope eases the pain of JavaScript OO. It’s a simple class and extends the Object object by adding two instance methods and one class method.

The Base class defines two instance methods:

extend
------
Call this method to extend an object with another interface:

    var object = new Base;
    object.extend({
      value: "some data",
      method: function() {
        alert("Hello World!");
      }
    });
    object.method();
    // ==> Hello World!
    
base
----
If a method has been overridden then the base method provides access to the overridden method:

    var object = new Base;
    object.method = function() {
      alert("Hello World!");
    };
    object.extend({
      method: function() {
        // call the "super" method
        this.base();
        // add some code
        alert("Hello again!");
      }
    });
    object.method();
    // ==> Hello World!
    // ==> Hello again!
    
You can also call the base method from within a constructor function.

Creating Classes
================
Classes are created by calling the extend method on the Base class:

    var Animal = Base.extend({
      constructor: function(name) {
        this.name = name;
      },
  
      name: "",
  
      eat: function() {
        this.say("Yum!");
      },
  
      say: function(message) {
        alert(this.name + ": " + message);
      }
    });
    
All classes created in this manner will inherit the extend method so we can easily subclass the Animal class:

    var Cat = Animal.extend({
      eat: function(food) {
        if (food instanceof Mouse) this.base();
        else this.say("Yuk! I only eat mice.");
      }
    });
  
    var Mouse = Animal.extend();
    
Class Properties and Methods
============================
A second parameter passed to the extend method of a class defines the class interface:

    var Circle = Shape.extend({ // instance interface
      constructor: function(x, y, radius) {
        this.base(x, y);
        this.radius = radius;
      },
  
      radius: 0,
  
      getCircumference: function() {
        return 2 * Circle.PI * this.radius;
      }
    }, { // class interface
      PI: 3.14
    });
    
Note the use of the base method in the constructor. This ensures that the Shape constructor is also called. Some other things to note:

  * If you define a class method (not an instance method) called init it will be automatically called when the class is created
  * Constructor functions are never called during the prototyping phase (subclassing)
  
Classes With Private Data
=========================
Some developers prefer to create classes where methods access private data:

    function Circle(radius) {
      this.getCircumference = function() {
        return 2 * Math.PI * radius;
      };
    };
    
You can achieve the same result using the Base class:

    var Circle = Shape.extend({
      constructor: function(radius) {
        this.extend({
          getCircumference: function() {
            return 2 * Math.PI * radius;
          }
        });
      }
    });
    
The code is slightly more verbose in this case but you get access to the base method which I find incredibly useful.

Single Instances
================

I changed my mind a lot about this but finally decided to allow the creation of single instance classes by defining a null constructor:

    var Math = Base.extend({
      constructor: null,
      PI: 3.14,
      sqr: function(number) {
        return number * number;
      }
    });