jQuery $.data()方法使用注意细节
人气:0
前段时间同事在群里对jQuery里的.data()方法大发牢骚:
XXX(NNNNNNN) 15:11:34
<a id="a" data-xxx="00123" />
alert($('#a').data('xxx'));//123
data方法不靠谱
XXX(NNNNNNN) 15:13:17
老老实实用attr('data-xxx')吧细研究了下jQuery文档对.data()方法的描述:
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.
针对如下示便:
<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";
即当使用.data()获取值时,jQuery会首先尝试将获取的字符串值转化成JS类型,包括布尔值,null,数字,对象,数组:
若值是”true|false”,则返回相应的布尔值;
若值是”null”,则返回null;
若值是纯数字构成的字符串(+data + ”” === data),则返回相应的数字(+data);
若值是由(?:\{[\s\S]*\}|\[[\s\S]*\])$,比如”{key:value}“或[1,2,3],则尝试使用jQuery.parseJSON解析之;
否则返回字符串值
当然文档里也特意说明了——如果就是想获取字符串值而不想获得自动转换的值,可以使用.attr(“data-”+key)来获取相应的值:
To retrieve the value's attribute as a string without any attempt to convert it, use the attr() method.
如下为jQuery源码
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)方法尝试将获取的值转化成JS类型,包括布尔值,null,数字,对象,数组*/
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]*\}|\[[\s\S]*\])$/,*/
rbrace.test( data ) ? jQuery.parseJSON( data ) :
data;
} catch( e ) {}
// Make sure we set the data so it isn't changed later
jQuery.data( elem, key, data );
} else {
data = undefined;
}
}
return data;
}
XXX(NNNNNNN) 15:11:34
<a id="a" data-xxx="00123" />
alert($('#a').data('xxx'));//123
data方法不靠谱
XXX(NNNNNNN) 15:13:17
老老实实用attr('data-xxx')吧细研究了下jQuery文档对.data()方法的描述:
复制代码 代码如下:
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.
针对如下示便:
复制代码 代码如下:
<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";
即当使用.data()获取值时,jQuery会首先尝试将获取的字符串值转化成JS类型,包括布尔值,null,数字,对象,数组:
若值是”true|false”,则返回相应的布尔值;
若值是”null”,则返回null;
若值是纯数字构成的字符串(+data + ”” === data),则返回相应的数字(+data);
若值是由(?:\{[\s\S]*\}|\[[\s\S]*\])$,比如”{key:value}“或[1,2,3],则尝试使用jQuery.parseJSON解析之;
否则返回字符串值
当然文档里也特意说明了——如果就是想获取字符串值而不想获得自动转换的值,可以使用.attr(“data-”+key)来获取相应的值:
复制代码 代码如下:
To retrieve the value's attribute as a string without any attempt to convert it, use the attr() method.
如下为jQuery源码
复制代码 代码如下:
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)方法尝试将获取的值转化成JS类型,包括布尔值,null,数字,对象,数组*/
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;
}
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