# 
[](http://travis-ci.org/zhongxingdou/mayjs)
[](http://badge.fury.io/js/mayjs)
[](https://sourcegraph.com/github.com/zhongxingdou/mayjs)
[](https://nodei.co/npm/mayjs/)
## Principle
+ Simple, but clear
+ Focus better javascript
+ Keep JavaScript as JavaScript
## Features
+ object wrapping
similary $() in jQuery but supported wrap any object
+ module
inspirits by module of Ruby
+ classes and inheritance
bring onExtend() and onInitialize() hook and more
+ interface
for documentation implicit interface and validate objects
+ method overload
help you clean up type assertion of paramerters in function head lines
+ keyword-like function
a series of function to simplify complex expressions and repetitive code
## Install
install for nodejs
```bash
npm intall mayjs
```
install for browser
```bash
bower install mayjs
```
## Getting started
The quickest way to start using May.js in your project, is by simply including may.js
```html
```
Export May.js keyword-like function to global object
```javascript
M.exportDSL(M.global);
// so you will got $class $module $interface $fn ...
```
## Module
```javascript
var MEvent = $module({
onIncluded: function(obj){
obj.__observers = {};
},
subscribe: function(obj, eventName, observer){
if(!obj.__observers[eventName]) obj.__observers[eventName] = [];
obj.__observers[eventName].push(observer);
},
publish: function(obj, eventName, data){
(obj.__observers[eventName] || []).forEach(function(observer){
observer(data);
});
},
__option__: {
methodize: true
}
});
var man = {};
$include(man, MEvent);
man.setName = function(name){
this.name = name;
this.publish("nameChanged", name);
}
man.subscribe("nameChanged", function(newName){
console.info("name changed to:" + newName);
});
man.setName("Hal"); // => name changed to:Hal
man.setName("Jerry"); // => name changed to:Jerry
```
## Object wrap
```javascript
// register a global wrapper
M.$.reg({
mix: function(obj, src){
for(var p in src){ obj[p] = src[p] }
},
__option__: {
methodize: true,
supports: [Object]
}
});
M(function($, $$){
//$() and $$() both use the same wrapper table
var Jim = {};
$(Jim).mix({
name: "Jim",
age: 20
});
Jim.name; // => Jim
Jim.hasOwnProperty("mix"); // => false
typeof(Jim.mix); // => undefined
$$(Jim); //copy mix() to Jim directly
Jim.hasOwnProperty("mix"); // => true
//register a wrapper locally
$.reg({
next: function(num){
return num + 1;
},
__option__: {methodize: true}
}, Number);
$(8).next(); // => 9
})
M.$(8).next() //Oh, no!
```
## Classes and inheritance
```javascript
M(function(){
var Animal = $class({
initialize: function(name){
var _name = name || "";
this.getName = function(){
return _name;
}
},
eat: function(food){
return this.getName() + " is eating " + food;
}
});
var Duck = Animal.extend({
initialize: function(name){
this.base(name);
},
eat: function(food){
return this.base(food) + ", she is so happy: quack quack!"
}
});
var monkey = new Animal("monkey");
monkey.eat("banana"); // => monkey is eating banana
var duck = new Duck("Litter yellow duck");
duck.eat("grass"); // => Little yellow duck is eating grass, she is so happy: quack quack!
});
```
## Interface
Using interface to validate object
```javascript
M(function(){
var IStudent = $interface({
name: String,
birthday: Date,
"[interest]": String
});
var Student = $class({
initialize: function(studentInfo){
$support(IStudent, studentInfo);
$mix(this, studentInfo);
}
});
var Jim = new Student({
name: "Jim",
birthday: new Date("1988/08/08")
});
var Lily = new Student({
name: "Luly",
birthday: new Date,
interest: "swimming"
});
$ensure(function(){
var Lucy = new Student({
name: "Lucy",
birthday: "1990/08/08"
});
// => error: birthday invlid
});
});
```
Implementation interface
```javascript
M(function($, $$){
var IMoveAble = $interface({
move: Function
});
var Car = $class({
initialize: function(name){
this.name = name;
},
move: function(place){
console.info(this.name + " is running to " + place);
}
});
$implement(IMoveAble, Car.prototype);
var Man = $class({
initialize: function(name){
this.name = name;
},
move: function(place){
console.info(this.name + " is walking to " + place);
}
});
$implement(IMoveAble, Man.prototype);
```
Register an module map to an interface
``` javascript
//continued codeblock above
var MoveStatus = $enum("Stoped", "Moving", "Arrived");
var Marathon = $module({
gotoPlace: function(obj, place, distance, secondsSpeed){
obj.status = MoveStatus.Moving;
obj.__moveTask ={
place: place,
distance: distance,
speed: secondsSpeed,
lastCounterTime: new Date
}
},
cancel: function(){
obj.status = MoveStatus.Stoped;
},
checkStatus: function(obj){
var task = obj.__moveTask;
switch(obj.status){
case MoveStatus.Stoped:
console.log(obj.name + ": Stoped");
break;
case MoveStatus.Moving:
var movedSeconds = (new Date() - task.lastCounterTime) / 1000;
var movedDistance = Math.round(movedSeconds * task.speed * Math.random());
if(movedDistance < task.distance){
obj.move(task.place);
var remaining = task.distance - movedDistance;
console.log(" To " + task.place + " remaining: " + remaining);
task.distance = remaining;
task.lastCounterTime = task.lastCounterTime;
}else{
obj.status = MoveStatus.Arrived;
}
break;
case MoveStatus.Arrived:
console.info(obj.name + ": Arrived");
break;
}
return obj.status;
},
onIncluded: function(obj){
obj.status = MoveStatus.Stoped;
},
__option__: {
methodize: true
}
});
$.reg(Marathon, IMoveAble);
var toyota = new Car("Toyota");
var liuXiang = new Man("LiuXiang");
//liuXiang and toyota will wrapping by Marathon cause Car and Man both implementation IMoveAble
var marathonMan = $(liuXiang);
var marathonCar = $(toyota);
marathonCar.gotoPlace("Beijing", 3 * 1000, 20);
marathonMan.gotoPlace("Home", 1 * 1000, 8);
var timer = setInterval(function(){
if(marathonMan.checkStatus() == MoveStatus.Arrived){
console.info("==== LiuXiang Win ====")
return clearInterval(timer);
}
if(marathonCar.checkStatus() == MoveStatus.Arrived){
console.info("==== Toyota Win ====")
clearInterval(timer);
}
}, 3000);
});
```
## Method overload
may.js $overload() rely on interface and $is()
lets write a tiny jQuery
```javascript
M(function($, $$){
var supportCollectionFn = function(fn){
return function(el){
var self = this;
var args = Array.prototype.slice.call(arguments, 1);
if(el instanceof HTMLCollection || el instanceof NodeList){
var result;
Array.prototype.slice.call(el).forEach(function (item) {
result = fn.apply(self, [item].concat(args));
});
return result;
}else{
return fn.apply(self, arguments);
}
}
}
var DomHelper = {
css: supportCollectionFn(function(el, cssProp, cssValue){
el.style[cssProp] = cssValue;
return this;
}),
html: supportCollectionFn(function(el, html){
if(html){
el.innerHTML = html;
}else{
return el.innerHTML;
}
return this;
}),
prop: supportCollectionFn(function(el, prop, propValue){
if(propValue){
el[prop] = propValue;
}else{
return el[prop];
}
return this;
}),
__option__: {
supports: [Element.prototype, NodeList.prototype, HTMLCollection.prototype],
methodize: true
}
}
$.reg(DomHelper);
var jjQuery = $overload([String], function(selector){
return $(document.querySelectorAll(selector));
}).overload([Element.prototype],function(el){
return $(el);
}).overload([HTMLCollection.prototype],function(els){
return $(els);
}).overload([String,Element.prototype], function(selector, parentElement){
return $(parentElement.querySelectorAll(selector));
}).overload([/^#[^ ]*/],function(id){
return $(document.getElementById(id));
});
//we assume you have some html like below
/*
*/
jjQuery("#content").html("Hi, Mayjs!");
jjQuery(document.body).css("backgroundColor","gray");
jjQuery(document.forms).css("backgroundColor", "blue");
jjQuery("button", document.forms[0]).prop("disabled", true);
jjQuery("#myForm input").css("backgroundColor", "yellow");
})
```
## Keyword-like function
assertion
```javascript
$is("string", "hello");
$is(String, "hello");
$is(Array, []);
$is(null, undefined);
A=$class({});
$is(A, new a);
$hasProto(A.prototype, new A);
function Person(name, age){
$check($is(String, name), "name invalid");
$check($is(Number, age), "age invalid");
this.name = name;
this.age = age;
}
var lily = new Person("lily", "16"); //throw error=> age invalid
```
syntactic sugar
```javascript
//$obj() object extend
var a=$obj({name: "jerry", "gender":"male"});
var b=a.extend({name:"hal", age:18});
b.gender; // => male
a.isPrototypeOf(b); // => true
//$run() just run function
$run(function(){
console.info("hello, mayjs");
});
//$ensure() Preventing errors thrown
var errorFn = function(){
throw "some error"
}
$ensure(errorFn); // => false
$ensure(function(){}); // => undefined
$ensure(function(){ return "hello"; }); // => hello
// $methodize()
// in may.js, 'Pure function' means the function which does not refer to this object
function capitalize(string){
return string.charAt(0).toUpperCase() + string.slice(1);
}
var china = new String("china"); //value type object can't have members
// string "china" will be binding as first parameter for capitalize
china.capitalize = $methodize(capitalize, china);
china.capitalize(); // => China
// $overwrite()
var a={hi: function(){
return "hello";
}}
$overwrite(a, "hi", function(hi){
return hi() + " world!";
})
a.hi(); // => hello world!
// $merge()
var man = function(option){
option = $merge({name: "noname"}, {age: 0}, option);
return option;
}
var hal = man({name: "hal", age: 20});
hal.name; // => hal
hal.age; // => 20
// $mix()
var a = {};
$mix(a, {name: "jim"});
a.name; // => jim
// $enum()
var Gender = $enum("Male","Female")
// both are unique object
typeof Gender.Male // => object
typeof Gender.Female // => object
var Gender2 = {
male: 1,
female: 2
}
Gender2 == $enum(Gender2); // => true
```
## License
Copyright (c) 2015 Zhong Xingdou
Licensed under the MIT license.