為jQuery提供一些實用擴展API：Lithium for jQuery

Lithium為jQuery提供一些實用擴展API：

1. 數據類型聲明: isDefined,isElement...
2. 綁定，繼承，命名空間...
3. 觀察模式(發布-訂閱模式) 可用于松耦合的模塊/組件之間進行通信。
4. IE8 JS 1.6 and JS 1.8 polyfills, like string trim, array forEach,lastIndexOf,filter,reduce...
5. 瀏覽器檢測(which is still useful in rare cases..like for statistics).

Lithium 依賴于jQuery。Lithium 劃分開成模塊，所以你可以只導入你所需要的使用的模塊。

瀏覽器支持

最新的Chrome,Firefox,Safari,Opera and IE8+.

API

Complete API documentation.

數據類型

Li.isDefined(val) - 返回true如果val不是undefined.

Li.isElement(o) - Returns true if o is an instance of HTMLElement

Li.isNaN(val) - Returns true if val is NaN.

Similarly Li.isObject, Li.isString, Li.isBoolean.

jQuery already has $.isFunction, $.isNumeric etc.

Patterns

• Li.namespace(string) - Creates a global namespace.

  Li.namespace('app.utils');

• Li.extend(base, obj) - Classical inheritence

  var myClass1 = Li.extend(Object, {
      constructor: function (cfg) {
          $.extend(this, cfg);
      },
      prop: "Lithium",
      method: function () { return 1;},
      statics: { //Special property to defined static methods/properties
          staticProp: "prop"
      }
  });
  
  //Create myClass2 using myClass1 as base class.
  var myClass2 = Li.extend(myClass1, {
      constructor: function (cfg) {
          this.super([cfg]); //call base class constructor
  
          //alternatively, this.super(arguments);
          //or this.superClass().constructor.call(this, cfg);
      },
      //Override 'method'
      method: function () {
          //Add 1 to the result of base class 'method'.
          return 1 + this.super(arugments);
      }
  });

• Observable

  var Restaurant = Li.extend(Object, {
      //Methods
      salesOffer: function () {
          this.fireEvent('freefood', '1.00 PM');
      }
  });
  Li.observable(Restaurant, ['freefood']); //Make class a publisher
  
  /*Subscriber/Listener*/
  var HungryMan = Li.extend(Object, {
      constructor: function (name, restaurant) {
          this.name = name;
          //Add listener
          restaurant.on('freefood', function (time) {
              console.log(name + ' says: Yay! free food!');
          }, this);
      }
  });
  /*----------------------------------*/
  
  /*Demonstration*/
  /*----------------------------------*/
  var someRestaurant = new Restaurant();
  var a = new HungryMan('man1', someRestaurant),
      b = new HungryMan('man2', someRestaurant);
  
  //Somewhere in a onclick event we execute...
  someRestaurant.salesOffer(); //...this would call all listeners. In this case it will display..
  //man1 says: Yay! free food!
  //man2 says: Yay! free food!

• Li.lbind(fn [, context, args...]) - Binds context and arguments to a function (like the JS.1.8.1 Function.bind). Argument list is prepended to fn.

  element.onclick = Li.lbind(function (val, e) {
    console.log(this ===  element); //true
    console.log(val); //10
    console.log(e); //If IE9+, you'll get event.
  }, element, 10);

• Li.rbind - Same as lbind, except that arguments are appended to fn arugment list.

• Li.forEach(obj [, callback, context]) - forEach on any object. For arrays, Array.forEach is called internally.

• Li.uuid([len=10, hypenate=false]) - Returns a random UID with length 'len' and hyphenated if hypenate=true, as string.
• Li.object.value(obj) - Returns all values of an object. Object.keys(obj) would return keys of an object.
• Li.object.size(obj) - Returns the number of enumerable properties of the object.
• Li.string.htmlEncode and Li.string.htmlDecode - Encodes/Decodes >,<," and &.

• Li.format(formatString, ...) - A quick string format method

  Li.format('<div class="{0}"></div>, 'box');
  Li.format('<div class="{cls}"></div>, {cls: 'box'});
  //Both returns '<div class="box"></div>'

• Li.dom(htmlString, ...) - Converts htmlString to DOM, inserts them into a document fragment and returns the fragment. Internally this uses Li.format for string formatting.

  var df = Cu.dom('<div class="{cls}" data-id="{id}"></div>', {cls: 'box', id: Cu.uuid()}); //DocumentFragment
  document.body.appendChild(df);

Browser Detection

Li.isIE - will be set when browser is MS IE.
Li.isIE9 - will be set when browser is MS IE 9.
Li.isChrome
Li.isWebKit
...similar for other browsers and versions
Li.isAndroid
Li.isIPhone
Li.isIPad
Li.isMobile - True if iPhone, Android, BlackBerry (Phone), Windows Phone or Symbian.

Additionally:
Li.browser.name - e.g. 'IE'
Li.browser.version - e.g. '9'
Li.browser.OS - e.g. 'Windows'
Li.browser.OSVersion (set if available) - e.g. '6.1'

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