mirror of
https://github.com/danog/inline-critical.git
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126 lines
3.3 KiB
JavaScript
126 lines
3.3 KiB
JavaScript
/**
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* Module to inline styles while loading the existing stylesheets async
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*
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* @author Ben Zörb @bezoerb https://github.com/bezoerb
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* @copyright Copyright (c) 2014 Ben Zörb
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*
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* Licensed under the MIT license.
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* http://bezoerb.mit-license.org/
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* All rights reserved.
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*/
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'use strict';
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var _ = require('lodash');
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var fs = require('fs');
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var path = require('path');
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var UglifyJS = require("uglify-js");
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var cave = require('cave');
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var reaver = require('reaver');
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var cheerio = require('cheerio');
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var render = require('dom-serializer');
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var parse = require('cheerio/lib/parse');
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var CleanCSS = require('clean-css');
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var slash = require('slash');
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var normalizeNewline = require('normalize-newline');
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// get loadCSS
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var loadCSS = read(path.join(__dirname, 'vendor', 'loadCSS.js'));
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loadCSS = UglifyJS.minify(loadCSS, {fromString: true}).code;
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/**
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* Fixup slashes in file paths for windows
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* @param {string} str
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* @return {string}
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*/
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function normalizePath(str) {
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return process.platform === 'win32' ? slash(str) : str;
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}
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/**
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* Read file *
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* @param {string} file
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* @returns {string}
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*/
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function read(file) {
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return fs.readFileSync(file, 'utf8');
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}
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module.exports = function (html, styles, options) {
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var $ = cheerio.load(String(html), {
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decodeEntities: false
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});
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var links = $('link[rel="stylesheet"]').filter(function () {
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return !$(this).parents('noscript').length;
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});
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var noscript = $('<noscript>\n</noscript>');
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var o = options || {};
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if (_.isString(o.ignore)) {
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o.ignore = [o.ignore];
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}
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if (o.ignore) {
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links = links.filter(function () {
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var href = $(this).attr('href');
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return _.findIndex(o.ignore, function (arg) {
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return _.isRegExp(arg) && arg.test(href) || arg === href;
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}) === -1;
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});
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}
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// minify if minify option is set
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if (o.minify) {
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styles = new CleanCSS().minify(styles).styles;
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}
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// insert inline styles right before first <link rel="stylesheet" />
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links.eq(0).before('<style type="text/css">\n' + styles + '\n</style>\n');
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// insert noscript block right after stylesheets
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links.eq(0).first().after(noscript);
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var hrefs = links.map(function (idx, el) {
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return $(this).attr('href');
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}).toArray();
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// extract styles from stylesheets if extract option is set
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if (o.extract) {
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if (!o.basePath) {
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throw new Error('Option `basePath` is missing and required when using `extract`!');
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}
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hrefs = hrefs.map(function (href) {
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var file = path.resolve(path.join(o.basePath, href));
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if (!fs.existsSync(file)) {
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return href;
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}
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var diff = normalizeNewline(cave(file, {css: styles}));
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fs.writeFileSync(reaver.rev(file, diff), diff);
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return normalizePath(reaver.rev(href, diff));
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});
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}
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// wrap links to stylesheets in noscript block so that they will evaluated when js is turned off
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links.each(function (idx) {
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var el = $(this);
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el.attr('href', hrefs[idx]);
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noscript.append(el);
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noscript.append('\n');
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});
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// build js block to load blocking stylesheets and insert it right before
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$(noscript).before('<script>\n' +
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'(function(u){' +
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loadCSS +
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'for(var i in u){loadCSS(u[i]);}' +
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'}([\'' + hrefs.join('\',\'') + '\']));\n' +
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'</script>\n');
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var dom = parse($.html());
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var markup = render(dom);
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return new Buffer(markup);
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};
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