Refresh / reload CSS bookmarklet

refresh-css.js

javascript:(function () {
    const now = Date.now().toFixed(2);

    /* Append timestamp to all linked stylesheet urls */
    for (const link of document.querySelectorAll('link[rel~="stylesheet"][href]')) {
        const url = new URL(link.href);
        url.searchParams.set('_cssrefresh', now);
        link.href = url.href;
    }

    for (const style of document.querySelectorAll('style')) {
        let css = style.innerHTML;

        /* Append timestamp to all @import-ed stylesheet urls */
        css = css.replace(/@import\s+?url\s*\(\s*(.+?)\s*\)\s*;/mg, function (m, url) {
            let oldUrl = url, newUrl = url, quote = '';
            if (url.startsWith("'") && url.endsWith("'")) {
                newUrl = url.slice(1, -1), quote = "'";
            } else if (url.startsWith('"') && url.endsWith('"')) {
                newUrl = url.slice(1, -1), quote = '"';
            }
            try {
                newUrl = new URL(newUrl);
                newUrl.searchParams.set('_cssrefresh', now);
                newUrl = quote + newUrl.href + quote;
                return m.replace(oldUrl, newUrl);
            } catch (e) {}
            try {
                newUrl = newUrl.replace(/[?&]_cssrefresh=([^&$]*)/, '');
                let qs = newUrl.indexOf('?') >= 0 ? '&' : '?';
                newUrl += `${qs}_cssrefresh=${now}`;
                newUrl = quote + newUrl + quote;
                return m.replace(oldUrl, newUrl);
            } catch (e) {}
            return m;
        });

        /* Append timestamp to end of stylesheet contents */
        const reRefresh = /\n\/\* _cssrefresh=(.+?) \*\/\n/mg;
        if (reRefresh.test(css)) {
            css = css.replace(reRefresh, function (m, then) {
                return `\n/* _cssrefresh=${now} */\n`;
            });
        } else {
            css += `\n/* _cssrefresh=${now} */\n`;
        }

        style.innerHTML = css;
    }
})();