Package Exports
- classy
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (classy) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
Classy - Classes for JavaScript
Classy offers the ability to easily define classes, call super or overriden methods, define static properties, and mixin objects in a very flexible way.
Meant to be used in the browser and in node.js as well.
Use dist/classy.js
var Vehicle = classy.define({
alias: 'vehicle',
init: function(year){
this.year = year
}
})
var Car = classy.define({
extend: 'vehicle'
//or extend: Vechicle
alias: 'car',
init: function(year, make){
this.callSuper()
this.make = make
},
getName: function(){
return this.make
}
})
var ford = new Car(1980, 'Ford')
console.log(ford.year)
console.log(ford.make)Notice the callSuper() method call, which can be used in any class method, and will call the method with the same name found on the super class. It also automatically transmits all the arguments it has, so you don't have to manually do so.
ford.getName() === 'Ford' //is true classy.override('car', {
getName: function(){
return this.callOverriden() + ', made in ' + this.year
}
})
//now
ford.getName() === 'Ford, made in 1980' //is trueYou can use the class alias in order to easily reference which class you want to extend or override. This also helps you get a reference to your class by
var Car = classy.getClass('car')
var Vehicle = classy.getClass('vehicle')init as constructor
Use the init method as the constructor
Example
var Animal = classy.define({
//when a new Animal is created, the init method is called
init: function(config){
config = config || {}
//we simply copy all the keys onto this
Object.keys(config).forEach(function(key){
this[key] = config[key]
}, this)
}
})
var Cat = classy.define({
extend: Animal,
alias: 'cat',
init: function(){
this.callSuper()
this.sound = 'meow'
},
getName: function(){
return this.name
}
})
var lizzy = new Cat({ name: 'lizzy' })callSuper and callOverriden
Use the callSuper and callOverriden methods to call the super and overriden methods. You don't have to worry about forwarding the arguments, since this is handled automagically for you.
If there is no super or overriden method with the same name you don't have to worry either, since callSuper and callOverriden won't break. they will simply and silently do nothing
Example
//create a shape class
classy.define({
alias: 'shape',
getDescription: function(){
return this.name
}
})
//create a rectangle class with a width and a height
classy.define({
extend: 'shape',
alias: 'rectangle',
name: 'rectangle',
init: function(size){
this.width = size.width
this.height = size.height
},
getArea: function(){
return this.width * this.height
},
setHeight: function(h){ this.height = h },
setWidth: function(w){ this.width = w }
})
classy.override('rectangle', {
getDescription: function(){
//reimplement the getDescription, but use the overriden implementation as well
return 'this is a ' + this.callOverriden()
}
})
//create a square class
classy.define({
extend: 'rectangle',
alias: 'square',
init: function(size){
if (size * 1 == size){
//the size is a number
size = { width: size, height: size}
} else {
size.width = size.height
}
this.callSuper()
},
setHeight: function(h){
//callSuper will automatically pass the arguments to Rectangle.setHeight, so h will be forwarded
this.callSuper() //or you could use this.callSuperWith(10) if you want to manually pass parameters
this.setWidth(h)
}
})You can also use callSuperWith and callOverridenWith to manually pass all parameters
Example
//...
setHeight: function(h){
this.callSuperWith(h*2)
}
//...Static properties and $ownClass
You can easily define static properties for classes.
var Widget = classy.define({
statics: {
idSeed: 0,
getDescription: function(){
return 'A Widget class'
},
getNextId: function(){
return this.idSeed++
}
},
init: function(){
this.id = this.$ownClass.getNextId()
}
})
Widget.getDescription() == 'A Widget class' // === true
var w = new Widget()
w.id === 0
w = new Widget()
w.id === 1On every instance, you can use the $ownClass property in order to get a reference to the class that created the instance.