Fiber.js: Lightweight, fast, JavaScript inheritance model


Why another JavaScript inheritance library?

Take a look at the performance tests to see how it compares against commonly used inheritance libraries.

Inheritance

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[[constructor]].extend( function )

#### Example

``javascript
// Animal base class
var Animal = Fiber.extend(function() {
return {
// The init method serves as the constructor.
init: function() {
// Private
function private1(){}
function private2(){}

// Privileged
this.privileged1 = function(){}
this.privileged2 = function(){}
},
// Public
method1: function(){}
}
});
`

The init method acts as the constructor, which is invoked when an instance is created:

`javascript
var animal = new Animal(); // Create a new Animal instance
`

init is invoked automatically.

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`javascript
// Extend the Animal class.
var Dog = Animal.extend(function() {
return {
// Override base class method1
method1: function(){
console.log('dog::method1');
},
scare: function(){
console.log('Dog::I scare you');
}
}
});
`

Create an instance of Dog:

`javascript
var husky = new Dog();
husky.scare(); // "Dog::I scare you'"
`

#### Accessing parent prototype

Every class definition has access to the parent's prototype via the first argument passed into the function:

`javascript
// Extend the Animal class.
var Dog = Animal.extend(function( base ) {
return {
// Override base class method1
method1: function(){
// Call the parent method
base.method1.call(this);
},
scare: function(){
console.log('Dog::I scare you');
}
}
});
`

Mixin

Mixins are a way to add functionality to a Fiber definition. Basically, they address the problem of "multiple inheritance". Read more.

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Fiber.mixin( object, function1, function2, ... )

`javascript
var Foo = Fiber.extend(function(base) {
return {
method1: function(){}
}
});

var f = new Foo();
f.method1();

var mix1 = function(base) {
return {
method2: function() {}
}
}

Fiber.mixin(Foo, mix1);

f.method2();
`

Decorators

With decorators you can dynamically attach additional properties to an instance. Read more.

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Fiber.decorate( instance, decorator_1, ... , decorator_n )

`javascript
function CarWithPowerWindows(base) {
return {
roll: function() {}
}
}

Fiber.decorate(myCar, CarWithPowerWindows);
`

Proxy

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Fiber.proxy( base, instance )

`javascript
// Extend the Animal class;
var Dog = Animal.extend(function(base) {
return {
init: function() {
this.base = Fiber.proxy(base, this);
this.base.init();
}
}
});
`

noConflict

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Fiber.noConflict()

Returns a reference to the Fiber object, and sets the Fiber` variable to its previous owner.