是否有任何JavaScript库可解析jQuery中使用的CSS规则？

Question

The goal is to pollyfill css3 nth-child pseudo-class with jQuery. So I need to parse css rules and reapply them with jQuery for older browsers that do not support nth-child directly from css. So I wrote some code, but I am pretty sure that something similar should be already present for example at github. May be someone already encountered such a problem? Here is my code:

        // if ie7 or ie8
        if (!$.support.leadingWhitespace) {         

            var aStyleSheetList = document.styleSheets,
                aRules = [],
                current = '',
                aSelectors = [];

            for (var i = 0; i < aStyleSheetList.length; i++) {
                aRules = aStyleSheetList[i].cssRules || aStyleSheetList[i].rules;
                for (var j = 0; j < aRules.length; j++) {
                    current = aRules[j];
                    if (current.selectorText && current.selectorText.indexOf('nth-child') !== -1) {
                        aSelectors.push([current.selectorText, current.cssText.substring(current.cssText.indexOf('{') + 1, current.cssText.indexOf('}'))]);
                    }
                }
            }

            var jqCssObject = {},
                declarations = [],
                keyValuePair = [];

            for (var k = 0; k < aSelectors.length; k++) {
                declarations = aSelectors[k][1].split(';');
                for (var m = 0; m < declarations.length; m++) {
                    keyValuePair = declarations[m].split(':');
                    jqCssObject[keyValuePair[0]] = keyValuePair[1];
                }
                $(aSelectors[k][0]).css(jqCssObject);                   
            }

        }

Answer 1

If you want to use pseudo-selectors such as nth-child in older browsers, one option is to use Selectivizr :

"Selectivizr is a JavaScript utility that emulates CSS3 pseudo-classes and attribute selectors in Internet Explorer 6-8."

As you're already using jQuery, all you have to do is include the Selectivizr <script> in your page and you will have compatibility for various pseudo/attribute selectors in older browsers.