extasy
- Extend function inspired by YUI, coffeescript, typescript and google closure inheritance patterns.
- 2.5k minified (950 bytes gzipped)
Install
Node
npm install extasyBrowser
component install extasybower install extasy<script src="extasy-browser.min.js"></script><script> function Child() {}; function Parent() {}; extasy(Child, Parent);</script>Docs
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Full Example
var extasy = require('./lib/main.js'); function Parent() {};Parent.prototype.foo = function(x, y) { return x + y;}; function Child() {};// must extend before overwriting prototype methods!extasy(Child, Parent);Child.prototype.foo = function(x, y) { return 2 + this.super_.foo(x, y);}; /*--------------------------------------no tests throw an error---------------------------------------*/var ChildInst = new Child(); var assert = require('assert');assert(ChildInst.constructor === Child);assert(ChildInst.super_ === Parent.prototype);assert(Object.getPrototypeOf(ChildInst) === Child.prototype);assert(Object.getPrototypeOf(Object.getPrototypeOf(ChildInst)) === Parent.prototype);assert(ChildInst instanceof Child);assert(ChildInst instanceof Parent); console.log('ok');API
extasy(childConstructor, ParentClass, StaticProps)
function Child() {};
function Parent() {};
extasy(Child, Parent, {
iam: 'optional static props'
}));
@param {Constructor} Child Constructor Class
Function for child class that you want to create
@param {Class|Array} ParentClass
A single class or an array of classes that you want the child to inherit from. The paren(t's/ts') methods will be put on the child's prototype. If the parent is a dynamic class (ie uses a constructor function) then the parent's prototype methods will be put on the child's prototype. If the parent is a static class (ie an object literal) then it's static methods will be put on the child's prototype. If an array of classes is passed in then these will be flattened (ie a single parent class combining all the methods to be inherited will be created) before applying to the child's prototype.
@param {[Object]} StaticProps
Optional instance methods to give the class when instantiated (won't be put on proto). By default the paren(t's/ts') instance methods are applied to the child as instance methods
@return {Class}
The child class is returned
Features
Accepts Constructor or Static Class Parents
Parent can be either a constructor or static class (ie constructor functions or object literals).
Constructor Parents
Parent's prototype methods are placed on child's prototype (static methods if parent is object literal).
function Child() {};function Parent() {};extasy(Child, Parent);var ChildInst = new Child();assert(ChildInst.super_ === Parent.prototype);assert(ChildInst.hello === 'world');Static Parents
function Child() {};var Parent = {};extasy(Child, Parent);assert(Child.super_ === Parent);var ChildInst = new Child();assert(ChildInst.constructor.super_ === Parent);Multiple Parents
function Child() {};function Parent() {};Parent.prototype.kinky = function () { return 'yes, ' + this.menage; };function Parent2() {};var Parent3 = {menage: 'a trois'}; // inheritextasy(Child, [Parent, Parent2, Parent3]);var ChildInst = new Child(); assert(Child.prototype.kinky === Parent.prototype.kinky);assert(ChildInst.constructor.prototype.kinky === Parent.prototype.kinky);assert(Child.kinky() === 'yes, a trois');assert(ChildInst.kinky() === 'yes, a trois');Copies Constuctor* Parent's Instance Methods & Properties
Parent's instance methods are set as child instance methods if parent is a constructor class. Does not do this for static classes because their 'instance' methods are put on the prototype
function Child() {};function Parent() {};Parent.prototype.random = 'randomness';Parent.random = 'random';Parent.bar = 'bar';extasy(Child, Parent);// differences child class vs instancevar ChildInst = new Child();assert(Child.bar === Parent.bar);assert(Child.super_ === undefined);assert(ChildInst.super_ !== undefined);assert(Child.random === Parent.random);assert(Child.random === 'random');assert(ChildInst.constructor.random === 'random');assert(ChildInst.super_.random === 'randomness');Overloading
Overloading Constructor Class Parent
function Child() {};function Parent() {};Parent.prototype.foo = function () { return 'father'; };extasy(Child, Parent); // extend the protoype after extending or else will fail...Child.prototype.foo = function () { return 'you are my ' + this.super_.foo();} // initialisevar ChildInst = new Child();assert(ChildInst.foo() === 'you are my father'); // overloadChildInst.foo = function () { return 'you WERE my ' + this.super_.foo();}assert(ChildInst.foo() === 'you WERE my father');Overloading Static Class Parent
function Child() {};var Parent = {foo: function () { return 'father'; }};extasy(Child, Parent); // can't overload thru prototype - need to do thru instanceassert(Child.super_.foo === Parent.foo);assert(Child.prototype.foo === Parent.foo);Child.foo = function () { return 'you are my ' + this.super_.foo();} // overloading instancevar ChildInst = new Child();assert(Child.foo() === 'you are my father');assert(ChildInst.constructor.foo() === 'you are my father');Overloading Multiple Parents
function Child() {};function Parent() {};Parent.prototype.kinky = function () { return 'yes, ' + this.menage; };function Parent2() {};var Parent3 = {menage: 'a trois'}; // inheritextasy(Child, [Parent, Parent2, Parent3]);var ChildInst = new Child(); // can't overload thru prototype - need to do thru instanceassert(Child.super_.kinky === Parent.prototype.kinky);assert(Child.prototype.kinky === Parent.prototype.kinky); // class overloadingChild.kinky = function () { return 'Q: Is my parent kinky? A: ' + this.super_.kinky();};assert(Child.kinky() === 'Q: Is my parent kinky? A: yes, a trois');assert(ChildInst.kinky() !== 'Q: Is my parent kinky? A: yes, a trois'); // instance overloadingvar ChildInstOverload = new Child();assert(ChildInstOverload.kinky() === 'yes, a trois');ChildInstOverload.kinky = function () { return 'Q: Is my class\'s parent kinky? A: ' + this.constructor.super_.kinky();};assert(ChildInstOverload.kinky() === 'Q: Is my class\'s parent kinky? A: yes, a trois');