前段時間同事在群裡對jQuery裡的.data()方法大發牢騷:
XXX(NNNNNNN) 15:11:34
<a id="a" data-xxx="00123" />
alert($('#a').data('xxx'));//123
data方法不靠譜
XXX(NNNNNNN) 15:13:17
老老實實用attr('data-xxx')吧細研究了下jQuery文檔對.data()方法的描述:
復制代碼 代碼如下:
As of jQuery 1.4.3 HTML 5 data- attributes will be automatically pulled in to jQuery's data object.
The treatment of attributes with embedded dashes was changed in jQuery 1.6 to conform to the W3C HTML5
specification.
針對如下示便:
復制代碼 代碼如下:
<div data-role="page" data-last-value="43" data-hidden="true" data-options='{"name":"John"}'></div>
$("div").data("role") === "page";
$("div").data("lastValue") === 43;
$("div").data("hidden") === true;
$("div").data("options").name === "John";
即當使用.data()獲取值時,jQuery會首先嘗試將獲取的字符串值轉化成JS類型,包括布爾值,null,數字,對象,數組:
若值是”true|false”,則返回相應的布爾值;
若值是”null”,則返回null;
若值是純數字構成的字符串(+data + ”” === data),則返回相應的數字(+data);
若值是由(?:\{[\s\S]*\}|\[[\s\S]*\])$,比如”{key:value}“或[1,2,3],則嘗試使用jQuery.parseJSON解析之;
否則返回字符串值 當然文檔裡也特意說明了——如果就是想獲取字符串值而不想獲得自動轉換的值,可以使用.attr(“data-”+key)來獲取相應的值:
復制代碼 代碼如下:
To retrieve the value's attribute as a string without any attempt to convert it, use the attr() method.
如下為jQuery源碼
復制代碼 代碼如下:
function dataAttr( elem, key, data ) {
// If nothing was found internally, try to fetch any
// data from the HTML5 data-* attribute
if ( data === undefined && elem.nodeType === 1 ) {
// rmultiDash = /([A-Z])/g
var name = "data-" + key.replace( rmultiDash, "-$1" ).toLowerCase();
data = elem.getAttribute( name );
if ( typeof data === "string" ) {
try {
/*.data(key)方法嘗試將獲取的值轉化成JS類型,包括布爾值,null,數字,對象,數組*/
data = data === "true" ? true :
data === "false" ? false :
data === "null" ? null :
// Only convert to a number if it doesn't change the string
+data + "" === data ? +data :
/*rbrace = /(?:\{[\s\S]*\}|\[[\s\S]*\])$/,*/
rbrace.test( data ) ? jQuery.parseJSON( data ) :
data;
} catch( e ) {}
// Make sure we set the data so it isn't changed later
jQuery.data( elem, key, data );
} else {
data = undefined;
}
}
return data;
}