编写jQueryUI插件(widget)

最近在做一个项目的时候，要实现动态渲染弹出框的样式，所以用到widget编写插件。学习一下。

使用Jquery ui 的widget来写插件，比较以实现，因为widget已经实现了一些基本的方法，如_create(),destroy(),其次是踏实单例的。

基本语法：

（function($){

function foo(){}

$.widget("命名空间.插件名"，$.继承插件的命名空间.插件名,{/snip/})

}）（jQuery）;

一般来说工具函数写在widget外面比较合适，但如果你想要这些工具函数被子类继承，则需要写在widget里面。

写在widget里面的，就有public和private之分，规则是：

public方法首字符不是_

private方法首字符是_

当调用方法时，会先判断是否以_开头，如果是则不执行调用。

如果我非要在外面调用private方法，该怎么做？并非一点办法也没有：

var instance = $('<div>');instance.mywidget('publicFunction'); // workinstance.mywidget('_privateFunction'); // silently failinstance.data('mywidget')._privateFunction(); // work$.mynamespace.mywidget.prototype._privateFunction(); // work

Jquery的官方文档中对此写的很清晰。一般来说，jquery ui都是继承自jquery.ui.widget.js这个文件的。这个文件提供了一个工厂方法来创建widget对象。其方法是$.widget(String name, Options prototype).下面简单介绍下这个类提供的方法和属性。在创建widget的时候将重写这些。

destroy()：将widget实例从dom对象上移除，在开发widget的时候一般此方法是必须的。就是移除你自己在dom element上添加的样式和行为以及dom结构

options：在这里面保存的是widget的配置信息，在创建widget的时候需要设置一些配置参数。

element：就是widget作用的dom对象。

enable()和disable()这两个方法就是禁用和启用widget的。其实是修改options.disabled。

还有两个私有方法是创建widget的时候要重写的。

_create() 这个方法就是创建widget的方法，在页面调用widget的时候，就会执行此方法，来构建widget。Widget的绝大大多数行为和结构都是在这里创建的。

_init() 这个方法大多数时候不会被重写，这个方法在构建widget的时候在_create后执行。从相关的文档上查询到：

_create()方法在widget构建的时候执行，而_init()方法在构建和重新初始化的时候执行。而destroy方法则是在移除widget的时候被执行。在widget中，所有的私有方法都将加以"_"前缀

_setOption():此方法提供了options的属性的设置，一般情况下如果options里面的参数不需要特殊处理（校验，类型转换，以及设置属性的时候触发某一操作等）的时候不需要对此方法进行重写

事件

如果有自定义的事件，可以采用widget为我们封装好的方法来处理_trigger()这个方法来处理，其调用方法 this._trigger(type, event, data)，第一个参数为时间类型，第二个参数为事件event对象，第三个参数为事件要传递的参数。

接下来会写一个简单的jquery ui widget来说明如何开发widget

代码Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->$(function(){
 
    // _create() 和 _init() 在第一次调用的时候被执行
    $("div").mywidget();
 
    // widget已经实例化到div上了，此时只执行_init()方法

 /* * jQuery Mobile Framework : plugin to provide a dialogs Widget. ver2 * Copyright (c) JTSage * CC 3.0 Attribution.  May be relicensed without permission/notifcation. * https://github.com/jtsage/jquery-mobile-simpledialog */ (function($, undefined ) {  $.widget( "mobile.simpledialog2", $.mobile.widget, {options: {version: '1.0.1-2012022700', // jQueryMobile-YrMoDaySerialmode: 'blank', // or 'button'themeDialog: 'b',themeInput: false,themeButtonDefault: false,themeHeader: 'a',fullScreen: false,fullScreenForce: false,dialogAllow: false,dialogForce: false,headerText: false,headerClose: false,buttonPrompt: false,buttonInput: false,buttonPassword: false,blankContent: false,resizeListener: true,safeNuke: true,forceInput: true,showModal: true,animate: true,transition: 'pop',clickEvent: 'click',zindex: '500',width: '580px',left: false,top: false,callbackOpen: false,callbackOpenArgs: [],callbackClose: false,callbackCloseArgs: []},_eventHandler: function(e,p) {// Handle the triggersvar self = e.data.widget,o = e.data.widget.options;if ( ! e.isPropagationStopped() ) {switch (p.method) {case 'close':self.close();break;case 'html':self.updateBlank(p.source);break;}}},_create: function () {var self = this,o = $.extend(this.options, this.element.jqmData('options')),initDate = new Date(),content = $("<div class='ui-simpledialog-container ui-overlay-shadow ui-corner-all ui-simpledialog-hidden " + ((o.animate === true) ? o.transition : '') + " ui-body-" + o.themeDialog + "'></div>");if ( o.themeButtonDefault === false ) { o.themeButtonDefault = o.themeDialog; }if ( o.themeInput === false ) { o.themeInput = o.themeDialog; }$.mobile.sdCurrentDialog = self;if ( typeof $.mobile.sdLastInput !== 'undefined' ) { delete $.mobile.sdLastInput; }self.internalID = initDate.getTime();self.displayAnchor = $.mobile.activePage.children('.ui-content').first();self.dialogPage = $("<div data-role='dialog' class='ui-simpledialog-dialog' data-theme='" + o.themeDialog + "'><div data-role='header'></div><div data-role='content'></div></div>");self.sdAllContent = self.dialogPage.find('[data-role=content]');content.appendTo(self.sdAllContent);self.sdIntContent = self.sdAllContent.find('.ui-simpledialog-container');self.sdIntContent.css('width', o.width);if ( o.headerText !== false || o.headerClose !== false ) {self.sdHeader = $('<div style="margin-bottom: 0px;background-color:black;" class="ui-header win-title ui-bar-'+o.themeHeader+'"></div>');if ( o.headerClose === true ) {$("<a class='ui-btn-right' rel='close' href='#'>Close</a>").appendTo(self.sdHeader).buttonMarkup({ theme  : o.themeHeader, icon   : 'delete', iconpos: 'notext', corners: true, shadow : true });}$('<h1 class="ui-title">'+((o.headerText !== false)?o.headerText:'')+'</h1>').appendTo(self.sdHeader);self.sdHeader.appendTo(self.sdIntContent);}if ( o.mode === 'blank' ) {if ( o.blankContent === true ) {o.blankContent = self.element.html();}$(o.blankContent).appendTo(self.sdIntContent);} else if ( o.mode === 'button' ) {self._makeButtons().appendTo(self.sdIntContent);}self.sdIntContent.appendTo(self.displayAnchor.parent());self.dialogPage.appendTo( $.mobile.pageContainer ).page().css('minHeight', '0px').css('zIndex', o.zindex);if ( o.animate === true ) { self.dialogPage.addClass(o.transition); }self.screen = $("<div>", {'class':'ui-simpledialog-screen ui-simpledialog-hidden'}).css('z-index', (o.zindex-1)).appendTo(self.displayAnchor.parent()).bind(o.clickEvent, function(event){if ( !o.forceInput ) {self.close();}event.preventDefault();});if ( o.showModal ) { self.screen.addClass('ui-simpledialog-screen-modal'); }$(document).bind('simpledialog.'+self.internalID, {widget:self}, function(e,p) { self._eventHandler(e,p); });},_makeButtons: function () {var self = this,o = self.options,buttonHTML = $('<div></div>'),pickerInput = $("<div class='ui-simpledialog-controls'><input class='ui-simpledialog-input ui-input-text ui-shadow-inset ui-corner-all ui-body-"+o.themeInput+"' type='"+((o.buttonPassword===true)?"password":"text")+"' name='pickin' /></div>"),pickerChoice = $("<div>", { "class":'ui-simpledialog-controls' });if ( o.buttonPrompt !== false ) {self.buttonPromptText = $("<p class='ui-simpledialog-subtitle'>"+o.buttonPrompt+"</p>").appendTo(buttonHTML);}if ( o.buttonInput !== false ) {$.mobile.sdLastInput = "";pickerInput.appendTo(buttonHTML);pickerInput.find('input').bind('change', function () {$.mobile.sdLastInput = pickerInput.find('input').first().val();self.thisInput = pickerInput.find('input').first().val();});}pickerChoice.appendTo(buttonHTML);self.butObj = [];$.each(o.buttons, function(name, props) {props = $.isFunction( props ) ? { click: props } : props;props = $.extend({text   : name,id     : name + self.internalID,theme  : o.themeButtonDefault,icon   : 'check',iconpos: 'left',corners: 'true',shadow : 'true',args   : [],close  : true}, props);self.butObj.push($("<a href='#'>"+name+"</a>").appendTo(pickerChoice).attr('id', props.id).buttonMarkup({theme  : props.theme,icon   : props.icon,iconpos: props.iconpos,corners: props.corners,shadow : props.shadow}).unbind("vclick click").bind(o.clickEvent, function() {if ( o.buttonInput ) { self.sdIntContent.find('input [name=pickin]').trigger('change'); }//var returnValue = props.click.apply(self.element[0], arguments);var returnValue = props.click.apply(self, $.merge(arguments, props.args));if ( returnValue !== false && props.close === true ) {self.close();}}));});return buttonHTML;},_getCoords: function(widget) {var self = widget,docWinWidth   = $.mobile.activePage.width(),docWinHighOff = $(window).scrollTop(),docWinHigh    = $(window).height(),diaWinWidth   = widget.sdIntContent.innerWidth(),diaWinHigh    = widget.sdIntContent.outerHeight(),coords        = {'high'    : $(window).height(),'width'   : $.mobile.activePage.width(),'fullTop' : $(window).scrollTop(),'fullLeft': $(window).scrollLeft(),'winTop'  : docWinHighOff + ((widget.options.top !== false) ? widget.options.top : (( docWinHigh / 2 ) - ( diaWinHigh / 2 ) )),'winLeft' : ((widget.options.left !== false) ? widget.options.left : (( docWinWidth / 2 ) - ( diaWinWidth / 2 ) ))};coords.winTop = 40;//if ( coords.winTop < 55 ) { coords.winTop = 40; }return coords;},_orientChange: function(e) {var self = e.data.widget,o = e.data.widget.options,coords = e.data.widget._getCoords(e.data.widget);e.stopPropagation();if ( self.isDialog === true ) {return true;} else {if ( o.fullScreen === true && ( coords.width < 400 || o.fullScreenForce === true ) ) {self.sdIntContent.css({'border': 'none', 'position': 'absolute', 'top': coords.fullTop, 'left': coords.fullLeft, 'height': coords.high, 'width': coords.width, 'maxWidth': coords.width }).removeClass('ui-simpledialog-hidden');} else {self.sdIntContent.css({'position': 'absolute', 'top': coords.winTop, 'left': coords.winLeft}).removeClass('ui-simpledialog-hidden');}}},repos: function() {var bsEvent = { data: {widget:this}, stopPropagation: function () { return true; }};this._orientChange(bsEvent);},open: function() {var self = this,o = this.options,coords = this._getCoords(this);self.sdAllContent.find('.ui-btn-active').removeClass('ui-btn-active');self.sdIntContent.delegate('[rel=close]', o.clickEvent, function (e) { e.preventDefault(); self.close(); });if ( ( o.dialogAllow === true && coords.width < 400 ) || o.dialogForce ) {self.isDialog = true;if ( o.mode === 'blank' ) { // Custom selects do not play well with dialog mode - so, we turn them off.self.sdIntContent.find('select').each(function () {$(this).jqmData('nativeMenu', true);});}self.displayAnchor.parent().unbind("pagehide.remove");self.sdAllContent.append(self.sdIntContent);self.sdAllContent.trigger('create');if ( o.headerText !== false ) {self.sdHeader.find('h1').appendTo(self.dialogPage.find('[data-role=header]'));self.sdIntContent.find('.ui-header').empty().removeClass();}if ( o.headerClose === true ) {self.dialogPage.find('.ui-header a').bind('click', function () {setTimeout("$.mobile.sdCurrentDialog.destroy();", 500);});} else {self.dialogPage.find('.ui-header a').remove();}self.sdIntContent.removeClass().css({'top': 'auto', 'width': 'auto', 'left': 'auto', 'marginLeft': 'auto', 'marginRight': 'auto', 'zIndex': o.zindex});$.mobile.changePage(self.dialogPage, {'transition': (o.animate === true) ? o.transition : 'none'});} else {self.isDialog = false;self.selects = [];if ( o.fullScreen === false ) {if ( o.showModal === true && o.animate === true ) { self.screen.fadeIn('slow'); }else { self.screen.removeClass('ui-simpledialog-hidden'); }}self.sdIntContent.addClass('ui-overlay-shadow in').css('zIndex', o.zindex).trigger('create');if ( o.fullScreen === true && ( coords.width < 400 || o.fullScreenForce === true ) ) {self.sdIntContent.removeClass('ui-simpledialog-container').css({'border': 'none', 'position': 'absolute', 'top': coords.fullTop, 'left': coords.fullLeft, 'height': coords.high, 'width': coords.width, 'maxWidth': coords.width }).removeClass('ui-simpledialog-hidden');} else {self.sdIntContent.css({'position': 'absolute', 'top': coords.winTop, 'left': coords.winLeft}).removeClass('ui-simpledialog-hidden');}$(document).bind('orientationchange.simpledialog', {widget:self}, function(e) { self._orientChange(e); });if ( o.resizeListener === true ) {$(window).bind('resize.simpledialog', {widget:self}, function (e) { self._orientChange(e); });}}if ( $.isFunction(o.callbackOpen) ) {o.callbackOpen.apply(self, o.callbackOpenArgs);}},close: function() {if($("#chioceDramaScope_" + g_currentPage)){$("#chioceDramaScope_" + g_currentPage).hide();}if(searchTextHidden==1){$("#searchText_searchResult").css("visibility","visible");searchTextHidden = 0;}if(searchTextHidden==2){$("#searchText_searchResult2").css("visibility","visible");searchTextHidden = 0;}var self = this, retty;if ( $.isFunction(self.options.callbackClose) ) {retty = self.options.callbackClose.apply(self, self.options.callbackCloseArgs);if ( retty === false ) { return false; }}if ( self.isDialog ) {$(self.dialogPage).dialog('close');self.sdIntContent.addClass('ui-simpledialog-hidden');self.sdIntContent.appendTo(self.displayAnchor.parent());if ( $.mobile.activePage.jqmData("page").options.domCache != true ) {$.mobile.activePage.bind("pagehide.remove", function () {$(this).remove();});}} else {if ( self.options.showModal === true && self.options.animate === true ) {self.screen.fadeOut('slow');} else {self.screen.addClass('ui-simpledialog-hidden');}self.sdIntContent.addClass('ui-simpledialog-hidden').removeClass('in');$(document).unbind('orientationchange.simpledialog');if ( self.options.resizeListener === true ) { $(window).unbind('resize.simpledialog'); }}$.mobile.activePage.find('.ui-btn-active').removeClass('ui-btn-active');if ( self.isDialog === true || self.options.animate === true ) {setTimeout("$.mobile.sdCurrentDialog.destroy();", 700);//update 2012-6-17 by wyx wo} else {self.destroy();}},destroy: function() {var self = this,ele = self.element;if ( self.options.mode === 'blank' ) {$.mobile.sdCurrentDialog.sdIntContent.find('select').each(function() {if ( $(this).data('nativeMenu') == false ) {$(this).data('selectmenu').menuPage.remove();$(this).data('selectmenu').screen.remove();$(this).data('selectmenu').listbox.remove();}});}$(self.sdIntContent).remove();$(self.dialogPage).remove();$(self.screen).remove();$(document).unbind('simpledialog.'+self.internalID);delete $.mobile.sdCurrentDialog;$.Widget.prototype.destroy.call(self);if ( self.options.safeNuke === true && $(ele).parents().length === 0 && $(ele).contents().length === 0 ) {ele.remove();}},updateBlank: function (newHTML) {var self = this,o = this.options;self.sdIntContent.empty();if ( o.headerText !== false || o.headerClose !== false ) {self.sdHeader = $('<div style="background-color:black" class="ui-header win-title ui-bar-'+o.themeHeader+'"></div>');if ( o.headerClose === true ) {$("<a class='ui-btn-right' rel='close' href='#'>Close</a>").appendTo(self.sdHeader).buttonMarkup({ theme  : o.themeHeader, icon   : 'delete', iconpos: 'notext', corners: true, shadow : true });}$('<h1 class="ui-title">'+((o.headerText !== false)?o.headerText:'')+'</h1>').appendTo(self.sdHeader);self.sdHeader.appendTo(self.sdIntContent);}$(newHTML).appendTo(self.sdIntContent);self.sdIntContent.trigger('create');$(document).trigger('orientationchange.simpledialog');},_init: function() {this.open();}  });})( jQuery );

    $("div").mywidget();
 
    // 销毁widget
    $("div").mywidget("destroy");
 
    // 因为widget已经被销毁，此时_create()和_init()方法都将被执行
    $("div").mywidget();
 
});