编写jQuery选择器不区分大小写的版本 [英] Writing jQuery selector case-insensitive version

问题描述

我正在使用以下行，并且希望使其不区分大小写:

I'm using following line and I would like to make it case-insensitive:

var matches = $(this).find('div > span > div#id_to_find[attributeName ^= "filter"]');
if (matches.length > 0) {
}

我的问题是，如何使选择器^=不区分大小写?也许更改为过滤器，然后再添加一些正则表达式?

My question is that how can I make the selector ^= to be case-insensitive? Maybe changing to filter and then some regexp?

推荐答案

要选择不区分大小写的属性，您需要编写一个自定义选择器函数.

To do a case-insensitive attribute selection, you need to write a custom selector function.

$.expr[':'].iAttrStart = function(obj, params, meta, stack) {
    var opts = meta[3].match(/(.*)\s*,\s*(.*)/);
    return (opts[1] in obj) && (obj[opts[1]].toLowerCase().indexOf(opts[2].toLowerCase()) === 0);
};

您可以这样使用:

$('input:iAttrStart(type, r)')

这将匹配其type属性以R或r开头的所有input元素(因此它将匹配RADIO，radio，RESET或reset).这是一个非常愚蠢的示例，但是它应该可以满足您的需求.

This will match any input elements whose type attribute begins with R or r (so it would match RADIO, radio, RESET or reset). This is a pretty silly example, but it should do what you need.

关于该功能难以理解的评论，我将对其稍作解释.

Re the comment that the function is hard to understand, I'll explain it a little.

$.expr[':'].iAttrStart = function(obj, params, meta, stack) {

这是用于创建自定义选择器的标准签名.

This is the standard signature for creating custom selectors.

var opts = meta[3].match(/(.*)\s*,\s*(.*)/);

meta是有关调用的详细信息的数组. meta[3]是作为参数传递的字符串.在我的示例中，这是type, r.正则表达式分别匹配type和r.

meta is an array of details about the call. meta[3] is the string passed as the parameter. In my example, this is type, r. The regex matches type and r separately.

return (opts[1] in obj) && (obj[opts[1]].toLowerCase().indexOf(opts[2].toLowerCase()) === 0);

如果这两个条件都成立，则返回:

Return if both these are true:

1. 请求的属性存在于此对象(opts[1] in obj)
2. 搜索项(更改为小写)位于元素属性值的开头，也更改为小写.

我本可以使用jQuery语法而不是本机JS语法来使其更易于阅读，但这将意味着性能降低.

I could have made this easier to read using jQuery syntax rather than native JS syntax, but that would have meant reduced performance.

这篇关于编写jQuery选择器不区分大小写的版本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！