CSS rules utilities

function allowing to find or change the CSS rule(s) applied to an element

Ce script ne devrait pas être installé directement. C'est une librairie créée pour d'autres scripts. Elle doit être inclus avec la commande // @require https://updategreasyfork.deno.dev/scripts/394970/768785/CSS%20rules%20utilities.js

// ==UserScript==
// @name         CSS rules utilities
// @namespace    http://tampermonkey.net/
// @version      0.4
// @description  functions allowing to get the CSS rules applied to an element
// @author       CoStiC
// @match        *://*/*
// @grant        none
// ==/UserScript==

function findCssRules(el) {
    var sheets = document.styleSheets, ret = [];
    el.matches = el.matches || el.webkitMatchesSelector || el.mozMatchesSelector || el.msMatchesSelector || el.oMatchesSelector;
    for (var i in sheets) {
        var rules = sheets[i].rules || sheets[i].cssRules;
        for (var r in rules) {
            if (el.matches(rules[r].selectorText)) {
                ret.push(rules[r].cssText);
            }
        }
    }
    return ret;
}

function modCssRules(el, newRule, frDoc) {
    if (!frDoc || (frDoc === window)) frDoc = window.document;
    let elHover = "",
        sheets = frDoc.styleSheets;

    if (el !== null) {
        el.matches = el.matches || el.webkitMatchesSelector || el.mozMatchesSelector || el.msMatchesSelector || el.oMatchesSelector;
        for (let sheet of sheets) {
            var rules = sheet.rules || sheet.cssRules;
            for (let rule of rules) {
                if (rule.type === 1) {
                    if (el.matches(rule.selectorText)) {

                        for (let newProp in newRule.cssNormal) {
                            rule.style[newProp] = newRule.cssNormal[newProp];
                        }

                        if (typeof newRule.cssHover !== 'undefined') {
                            var rul = "";
                            for (let propHover in newRule.cssHover) {
                                rul += `${propHover}:${newRule.cssHover[propHover]} !important;`;
                            };
                            elHover = `${rules[rule].selectorText}:hover{${rul}}`;
                        }
                    } else {};
                }
            }
        }
    }

    if (elHover !== "") {
        let newHoverStyle = document.createElement('style'),
            hoverRule = document.createTextNode(elHover);
        newHoverStyle.appendChild(hoverRule);
        document.head.appendChild(newHoverStyle)
        //sheets[sheets.length - 1].insertRule(elHover);
    };
}