jQuery ui Combobox 擴充套件

[img]http://dl2.iteye.com/upload/attachment/0099/9490/2cff105c-7e20-3ca0-a9f6-071f4096faac.png[/img]


[b]jQuery ui[/b] 是一個UI的雛形， 一些UI都基於jQuery ui 開發，例如easy ui。

最近專案用jquery ui 做前臺，需要用到 combobox元件， 如果用easy ui 需要引入很多其他的js比較麻煩， jquery ui Demo中 autocomplete 裡面自帶一個Combobox， 但一些功能不是我們想要的。
自己在上面增加了幾個方法和事件。 並修改了對IE6支援的CSS 如下：

[b]好處[/b]： 下拉框的樣式隨jquery ui 的樣式改變而改變， 支援自動補全
[b]不足[/b]： 方法需要自己擴充套件
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引數：
tip: "提示",
isReadonly: true, //預設下拉框值不可編輯， 如果設定為false， 那麼下拉框支援自動補全

增加方法說明：
事件：
1.onChange： 當下拉框修改選中一條時候觸發

方法：
主動設定下拉框內容
1.$( "#combobox" ).combobox('setSelect', 'option中value', 'option中text');

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測試：

Html：  
<select id="combobox">
...
</select>

依賴：  jquery ui 為1.9.1
需要依賴jquery ui、 jquery
<link rel="stylesheet" type="text/css" href="jquery/jqueryui/css/redmond/jquery-ui.custom.min.css" />
<link rel="stylesheet" type="text/css" href="jquery/jqueryui/combobox/jquery.combobox.css" />

<script src="jquery/jquery.min.js" type="text/javascript"></script>
<script src="jquery/jqueryui/js/jquery-ui.custom.min.js" type="text/javascript"></script>
<script src="jquery/jqueryui/combobox/jquery.combobox.js" type="text/javascript"></script>


$( "#combobox" ).combobox({
        tip: "滑鼠劃入下拉按鈕時候會有提示！",
	onChange: function(option){
		alert($(option).attr('value'));
	}
});

(function( $ ) {
	$.widget( "ui.combobox", {
		version: "1.9.1",
		options: {
			tip: "",
			isReadonly: true,
			/**
			 * This event fire after selected select.
			 */
			onChange: function(option) {}
		},
		input: null,
		_create: function() {
			var that = this,
			select = this.element.hide(),
			selected = select.children( ":selected" ),
			value = selected.val() ? selected.text() : "",
			wrapper = this.wrapper = $( "<span>" )
				.addClass( "ui-combobox" )
				.insertAfter( select );

			function removeIfInvalid(element) {
				var value = $( element ).val(),
					matcher = new RegExp( "^" + $.ui.autocomplete.escapeRegex( value ) + "$", "i" ),
					valid = false;
				select.children( "option" ).each(function() {
					if ( $( this ).text().match( matcher ) ) {
						this.selected = valid = true;
						return false;
					}
				});
				if ( !valid ) {
					// remove invalid value, as it didn't match anything
					$( element )
						.val( "" )
						.attr( "title", value + " 沒有匹配結果！" )
						.tooltip( "open" );
					select.val( "" );
					setTimeout(function() {
						input.tooltip( "close" ).attr( "title", "" );
					}, 2500 );
					input.data( "autocomplete" ).term = "";
					return false;
				}
			}

			input = $( "<input>" )
				.appendTo( wrapper )
				.val( value )
				.attr( "title", "" )
//				.addClass( "ui-state-default ui-combobox-input" )
				.addClass( "ui-combobox-input" )
				.autocomplete({
					delay: 0,
					minLength: 0,
					source: function( request, response ) {
						var matcher = new RegExp( $.ui.autocomplete.escapeRegex(request.term), "i" );
						response( select.children( "option" ).map(function() {
							var text = $( this ).text();
							if ( this.value && ( !request.term || matcher.test(text) ) )
								return {
									label: text.replace(
										new RegExp(
											"(?![^&;]+;)(?!<[^<>]*)(" +
											$.ui.autocomplete.escapeRegex(request.term) +
											")(?![^<>]*>)(?![^&;]+;)", "gi"
										), "<strong>$1</strong>" ),
									value: text,
									option: this
								};
						}) );
					},
					select: function( event, ui ) {
						ui.item.option.selected = true;
						that._trigger( "selected", event, {
							item: ui.item.option
						});

						that.options.onChange(ui.item.option);
					},
					change: function( event, ui ) {
						if ( !ui.item )
							return removeIfInvalid( this );
					}
				})
				.addClass( "ui-widget ui-widget-content ui-corner-left" );

			input.data( "autocomplete" )._renderItem = function( ul, item ) {
				return $( "<li>" )
					.data( "item.autocomplete", item )
					.append( "<a>" + item.label + "</a>" )
					.appendTo( ul );
			};

			$( "<a>" )
				.attr( "tabIndex", -1 )
				.attr( "title", this.options.tip )
				.tooltip()
				.appendTo( wrapper )
				.button({
					icons: {
						primary: "ui-icon-triangle-1-s"
					},
					text: false
				})
				//移除
//				.removeClass( "ui-button" )
				.removeClass( "ui-corner-all" )
				.addClass( "ui-corner-right ui-combobox-toggle" )
				.click(function() {
					// close if already visible
					if ( input.autocomplete( "widget" ).is( ":visible" ) ) {
						input.autocomplete( "close" );
						removeIfInvalid( input );
						return;
					}

					// work around a bug (likely same cause as #5265)
					$( this ).blur();

					// pass empty string as value to search for, displaying all results
					input.autocomplete( "search", "" );
					input.focus();
				});

				input
					.tooltip({
						position: {
							of: this.button
						},	
						tooltipClass: "ui-state-highlight"
					});

				if (this.options.isReadonly) {
					input.attr('readonly', true);
				}
		},

		destroy: function() {
			this.wrapper.remove();
			this.element.show();
			$.Widget.prototype.destroy.call( this );
		},
		/**
		 * Set input value 
		 * @param value option's value 
		 * @param text  option's text
		 */
		setSelect: function(value, text) {
			input.val(text);
		}
	});
})( jQuery );

CSS

.ui-combobox {
	position: relative;
	display: inline-block;
	padding-right: 20px;
}
.ui-combobox-toggle {
	position: absolute;
	top: 0;
	bottom: 0;
	margin-left: -1px;
	padding: 0 0 0 0;
	/* adjust styles for IE 6/7 */
	*height: 16px;
	*top: 0.1em;
	PADDING-RIGHT: 0px;
	width: 20px;
}
.ui-combobox-input {
	margin: 0;
	padding: 0em;
	width: 120px;
}