1.初始化项目 #
$ mkdir zhufengskeleton
$ cd zhufengskeleton
$ npm init -y
$ cnpm i css-tree @babel/core @babel/preset-env @babel/preset-react babel-loader cross-env fs-extra html-webpack-plugin webpack webpack-cli webpack-dev-server -D
$ cnpm i react react-dom -S
$ cnpm i puppeteer -D
2.React项目构建 #
2.1 webpack.config.js #
const HtmlWebpackPlugin = require('html-webpack-plugin');
const {resolve} = require('path');
module.exports = {
mode:'development',
devtool:false,
entry: "./src/index.js",
output: {
path:resolve(__dirname,'dist'),
filename: "main.js"
},
module: {
rules: [{
test: /\.js$/,
use: [
{
loader:'babel-loader',
options:{
presets:["@babel/preset-env","@babel/preset-react"]
}
}
],
exclude: /node_modules/
}]
},
devServer: {
contentBase: resolve(__dirname,'dist')
},
plugins: [
new HtmlWebpackPlugin({
template: './src/index.html'
})
]
}
2.2 src\index.js #
src\index.js
import React from 'react';
import ReactDOM from 'react-dom';
ReactDOM.render((
<div>
<img src="http://upload-markdown-images.oss-cn-beijing.aliyuncs.com/zhufengjg.jpg" width="100%"></img>
<button>点我点我</button>
</div>
),document.getElementById('root'));
2.3 src\index.html #
src\index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>skeleton</title>
</head>
<body>
<div id="root"><!-- shell --></div>
</body>
</html>
3. 创建插件 #
3.1 skeleton\index.js #
skeleton\index.js
const SkeletonPlugin = require('./SkeletonPlugin')
module.exports = {
SkeletonPlugin
}
3.2 SkeletonPlugin.js #
skeleton\SkeletonPlugin.js
const PLUGIN_NAME = 'SkeletonPlugin';
const defaultOptions = {
}
class SkeletonPlugin {
constructor(options){
this.options = {...defaultOptions,...options};
}
apply(compiler) {
compiler.hooks.done.tap(PLUGIN_NAME, async () => {
console.log(PLUGIN_NAME,'done');
})
}
}
module.exports = SkeletonPlugin;
3.3 webpack.config.js #
const HtmlWebpackPlugin = require('html-webpack-plugin');
const {resolve} = require('path');
+const {SkeletonPlugin} = require('./skeleton');
module.exports = {
mode:'development',
devtool:false,
entry: "./src/index.js",
output: {
path:resolve(__dirname,'dist'),
filename: "main.js"
},
module: {
rules: [{
test: /\.js$/,
use: [
{
loader:'babel-loader',
options:{
presets:["@babel/preset-env","@babel/preset-react"]
}
}
],
exclude: /node_modules/
}]
},
devServer: {
contentBase: resolve(__dirname,'dist')
},
plugins: [
new HtmlWebpackPlugin({
template: './src/index.html'
}),
+ new SkeletonPlugin({
+
+ })
]
}
4. 启动服务 #
4.1 webpack.config.js #
webpack.config.js
const HtmlWebpackPlugin = require('html-webpack-plugin');
const {resolve} = require('path');
const {SkeletonPlugin} = require('./skeleton');
module.exports = {
mode:'development',
devtool:false,
entry: "./src/index.js",
output: {
path:resolve(__dirname,'dist'),
filename: "main.js"
},
module: {
rules: [{
test: /\.js$/,
use: [
{
loader:'babel-loader',
options:{
presets:["@babel/preset-env","@babel/preset-react"]
}
}
],
exclude: /node_modules/
}]
},
devServer: {
contentBase: resolve(__dirname,'dist')
},
plugins: [
new HtmlWebpackPlugin({
template: './src/index.html'
}),
new SkeletonPlugin({
+ staticDir: resolve(__dirname,'dist'),
+ port:8000,
+ origin:'http://localhost:8000'
})
]
}
4.2 SkeletonPlugin.js #
skeleton\SkeletonPlugin.js
const PLUGIN_NAME = 'SkeletonPlugin';
+const Server = require('./Server');
const defaultOptions = {
}
class SkeletonPlugin {
constructor(options){
this.options = {...defaultOptions,...options};
}
apply(compiler) {
compiler.hooks.done.tap(PLUGIN_NAME, async () => {
+ await this.startServer();
+ await this.server.close();
})
}
+ async startServer(){
+ this.server = new Server(this.options);
+ await this.server.listen();
+ }
}
module.exports = SkeletonPlugin;
4.3 Server.js #
skeleton\Server.js
const http = require('http')
const express = require('express');
class Server {
constructor(options) {
this.options = options;
}
listen() {
const app = this.app = express();
app.use('/',express.static(this.options.staticDir));
this.listenServer = http.createServer(app);
return new Promise( (resolve) =>{
this.listenServer.listen(this.options.port, () => {
console.log(`server listen at port: ${this.options.origin}`);
resolve();
})
});
}
async close() {
return new Promise( (resolve) =>{
this.listenServer.close(() => {
console.log('server closed!');
resolve();
})
});
}
}
module.exports = Server;
5. 启动puppeteer #
5.1 webpack.config.js #
const HtmlWebpackPlugin = require('html-webpack-plugin');
const {resolve} = require('path');
const {SkeletonPlugin} = require('./skeleton');
module.exports = {
mode:'development',
devtool:false,
entry: "./src/index.js",
output: {
path:resolve(__dirname,'dist'),
filename: "main.js"
},
module: {
rules: [{
test: /\.js$/,
use: [
{
loader:'babel-loader',
options:{
presets:["@babel/preset-env","@babel/preset-react"]
}
}
],
exclude: /node_modules/
}]
},
devServer: {
contentBase: resolve(__dirname,'dist')
},
plugins: [
new HtmlWebpackPlugin({
template: './src/index.html'
}),
new SkeletonPlugin({
staticDir: resolve(__dirname,'dist'),
port:8000,
origin:'http://localhost:8000',
+ device: 'iPhone 6'
})
]
}
5.2 SkeletonPlugin.js #
skeleton\SkeletonPlugin.js
const PLUGIN_NAME = 'SkeletonPlugin';
const Server = require('./Server');
+const Skeleton = require('./Skeleton');
const defaultOptions = {
}
class SkeletonPlugin {
constructor(options){
this.options = {...defaultOptions,...options};
}
apply(compiler) {
compiler.hooks.done.tap(PLUGIN_NAME, async () => {
await this.startServer();
+ this.skeleton= new Skeleton(this.options);
+ await this.skeleton.initialize();
+ const skeletonHtml = await this.skeleton.genHtml(this.options.origin);
+ console.log('skeletonHtml',skeletonHtml);
+ await this.skeleton.destroy();
await this.server.close();
})
}
async startServer(){
this.server = new Server(this.options);
await this.server.listen();
}
}
module.exports = SkeletonPlugin;
5.3 Skeleton.js #
skeleton\Skeleton.js
let puppeteer = require('puppeteer');
class Skeleton {
constructor(options = {}) {
this.options = options
}
async initialize() {
this.browser = await puppeteer.launch({ headless: false });
}
async newPage() {
const { device } = this.options;
const page = await this.browser.newPage();
await page.emulate(puppeteer.devices[device]);
return page;
}
async genHtml(url) {
const page = await this.newPage()
const response = await page.goto(url, { waitUntil: 'networkidle2' });
if (response && !response.ok()) {
throw new Error(`${response.status} on ${url}`)
}
return 'html';
}
async destroy() {
if (this.browser) {
await this.browser.close();
this.browser = null
}
}
}
module.exports = Skeleton;
6. 截取骨架内容 #
6.1 SkeletonPlugin.js #
skeleton\SkeletonPlugin.js
const PLUGIN_NAME = 'SkeletonPlugin';
const Server = require('./Server');
const Skeleton = require('./Skeleton');
+const {resolve} = require('path');
+const {readFileSync,writeFileSync} = require('fs');
const defaultOptions = {
}
class SkeletonPlugin {
constructor(options){
this.options = {...defaultOptions,...options};
}
apply(compiler) {
compiler.hooks.done.tap(PLUGIN_NAME, async () => {
await this.startServer();
this.skeleton= new Skeleton(this.options);
await this.skeleton.initialize();
const skeletonHtml = await this.skeleton.genHtml(this.options.origin);
+ const originPath = resolve(this.options.staticDir,'index.html');
+ const orgiginHtml = await readFileSync(originPath, 'utf8');
+ const finalHtml = orgiginHtml.replace('<!-- shell -->',skeletonHtml);
+ await writeFileSync(originPath,finalHtml,'utf8');
+ await this.skeleton.destroy();
+ await this.server.close();
+ process.exit(0);
})
}
async startServer(){
this.server = new Server(this.options);
await this.server.listen();
}
}
module.exports = SkeletonPlugin;
6.2 Skeleton.js #
skeleton\Skeleton.js
let puppeteer = require('puppeteer');
+let {readFileSync} = require('fs');
+let {resolve} = require('path');
+let {sleep} = require('./utils');
class Skeleton {
constructor(options = {}) {
this.options = options
}
async initialize() {
this.browser = await puppeteer.launch({ headless: false });
}
async newPage() {
const { device } = this.options;
const page = await this.browser.newPage();
await page.emulate(puppeteer.devices[device]);
return page;
}
+ async makeSkeleton(page) {
+ const { defer = 5000 } = this.options;
+ const scriptContent = await readFileSync(resolve(__dirname, 'skeletonScript.js'), 'utf8');
+ await page.addScriptTag({ content: scriptContent })
+ await sleep(defer);
+ await page.evaluate((options) => {
+ Skeleton.genSkeleton(options);
+ }, this.options)
+ }
async genHtml(url) {
const page = await this.newPage()
const response = await page.goto(url, { waitUntil: 'networkidle2' });
if (response && !response.ok()) {
throw new Error(`${response.status} on ${url}`)
}
+ await this.makeSkeleton(page);
+ const { styles, html } = await page.evaluate(() => Skeleton.getHtmlAndStyle());
+ let result = `
+ <style>${styles.join('\n')}</style>
+ ${html}
+ `;
+ return Promise.resolve(result);
}
async destroy() {
if (this.browser) {
await this.browser.close()
this.browser = null
}
}
}
module.exports = Skeleton;
6.3 skeletonScript.js #
skeleton\skeletonScript.js
window.Skeleton = (function () {
const $$ = document.querySelectorAll.bind(document);
const REMOVE_TAGS = ['title', 'meta', 'style','script'];
function genSkeleton(options = {}) {
}
function getHtmlAndStyle() {
const styles = Array.from($$('style')).map(style => style.innerHTML || style.innerText);
Array.from($$(REMOVE_TAGS.join(','))).forEach(ele => ele.parentNode.removeChild(ele));
const html = document.body.innerHTML;
return { html, styles };
}
return {genSkeleton,getHtmlAndStyle};
}());
6.4 utils.js #
skeleton\utils.js
function sleep(duration) {
return new Promise((resolve) => {
setTimeout(resolve, duration)
})
}
module.exports = {
sleep
}
7. 元素转换 #
7.1 webpack.config.js #
webpack.config.js
const HtmlWebpackPlugin = require('html-webpack-plugin');
const {resolve} = require('path');
const {SkeletonPlugin} = require('./skeleton');
module.exports = {
mode:'development',
devtool:false,
entry: "./src/index.js",
output: {
path:resolve(__dirname,'dist'),
filename: "main.js"
},
module: {
rules: [{
test: /\.js$/,
use: [
{
loader:'babel-loader',
options:{
presets:["@babel/preset-env","@babel/preset-react"]
}
}
],
exclude: /node_modules/
}]
},
devServer: {
contentBase: resolve(__dirname,'dist')
},
plugins: [
new HtmlWebpackPlugin({
template: './src/index.html'
}),
new SkeletonPlugin({
staticDir: resolve(__dirname,'dist'),
port:8000,
origin:'http://localhost:8000',
device: 'iPhone 6',
+ image: {
+ color: '#EFEFEF',
+ },
+ button: {
+ color: '#EFEFEF',
+ }
})
]
}
7.2 skeletonScript.js #
skeleton\skeletonScript.js
window.Skeleton = (function () {
+ const SMALLEST_BASE64 = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
+ const CLASS_NAME_PREFEX = 'sk-';
const $$ = document.querySelectorAll.bind(document);
const REMOVE_TAGS = ['title', 'meta', 'style', 'script'];
+ const styleCache = new Map();
+ const setAttributes = (ele, attrs) => {
+ Object.keys(attrs).forEach(k => ele.setAttribute(k, attrs[k]));
+ };
+ const addStyle = (selector, rule) => {
+ if (!styleCache.has(selector)) {
+ styleCache.set(selector, rule)
+ }
+ }
+ function imgHandler(ele, options={}) {
+ const {width, height} = ele.getBoundingClientRect();
+ const attrs = {
+ width,
+ height,
+ src: SMALLEST_BASE64
+ };
+ setAttributes(ele, attrs);
+ const className = CLASS_NAME_PREFEX + 'image';
+ const rule = `{ background: ${options.color} !important;}`;
+ addStyle(`.${className}`, rule);
+ ele.classList.add(className)
+ }
+ function buttonHandler(ele,options={}) {
+ const classname = CLASS_NAME_PREFEX + 'button'
+ const rule = `{
+ color: ${options.color} !important;
+ background: ${options.color} !important;
+ border: none !important;
+ box-shadow: none !important;
+ }`
+ addStyle(`.${classname}`, rule)
+ ele.classList.add(classname)
+ }
function genSkeleton(options = {}) {
+ const rootElement = document.documentElement;
+ ;(function traverse(options) {
+ let { button, image } = options;
+ const buttons = [];
+ const imgs = [];
+ ;(function preTraverse(ele) {
+ if (ele.children && ele.children.length > 0) {
+ Array.from(ele.children).forEach(child => preTraverse(child))
+ }
+ if (ele.tagName === 'BUTTON') {
+ return buttons.push(ele);
+ }
+ if (ele.tagName === 'IMG') {
+ return imgs.push(ele)
+ }
+ })(rootElement);
+ buttons.forEach(e => buttonHandler(e, button))
+ imgs.forEach(e => imgHandler(e, image));
+ })(options);
+ let rules = ''
+ for (const [selector, rule] of styleCache) {
+ rules += `${selector} ${rule}\n`;
+ }
+ const styleEle = document.createElement('style')
+ styleEle.innerHTML = rules;
+ document.head.appendChild(styleEle)
}
function getHtmlAndStyle() {
const styles = Array.from($$('style')).map(style => style.innerHTML || style.innerText);
Array.from($$(REMOVE_TAGS.join(','))).forEach(ele => ele.parentNode.removeChild(ele));
const html = document.body.innerHTML;
return { html, styles };
}
return { genSkeleton, getHtmlAndStyle };
}());
8. cssTree #
8.1 cssTree.js #
const fs= require('fs')
const path= require('path')
const csstree = require('css-tree');
let createCode = async function (scssFilePath) {
let cssString = fs.readFileSync(scssFilePath,'utf8')
let ast = csstree.parse(cssString);
csstree.walk(ast, function (node) {
if (node.type == 'Dimension' && node.unit =='px') {
node.value = node.value/75;
node.unit ='rem';
}
});
let output = csstree.generate(ast);
fs.writeFile(path.join(__dirname,'output.css'), output, function () {
console.log('最终代码写入到output.css')
})
}
let scssFilePath= path.join(__dirname,'input.css');
createCode(scssFilePath);
8.2 input.css #
.avatar{
width: 750px;
}
8.3 output.css #
.avatar{width:10rem}
8.4 ast.json #
{
"type": "StyleSheet",
"loc": null,
"children": [
{
"type": "Rule",
"prelude": {
"type": "SelectorList",
"children": [
{
"type": "Selector",
"children": [
{
"type": "ClassSelector",
"name": "avatar"
}
]
}
]
},
"block": {
"type": "Block",
"children": [
{
"type": "Declaration",
"property": "width",
"value": {
"type": "Value",
"loc": null,
"children": [
{
"type": "Dimension",
"value": "750",
"unit": "px"
}
]
}
}
]
}
}
]
}
9. 参考 #
