如何打造高性能且SEO友好的单页应用(SPA)

如何打造⾼高性能 & SEO 友好单⻚页应⽤用(SPA)

#ngMY2019, 7⽉月6-7号 400+ 出席者, 30+ 国家

@JecelynYeen (阮阮⻉贝琪) • 编码⼗十年年 • ⾕谷歌开发者专家(GDE) • 软件架构师(Architect) • 培训
/ 咨询 • NG-MY 发起⼈人

⽣生平第⼆二次⽤用中⽂文演讲, 赏个脸，多多包涵, 别打盹！

@JecelynYeen ng-my.org

@JecelynYeen ➔项⽬目背景 ➔SEO优化 ➔提⾼高性能

7 项⽬目背景

@JecelynYeen 免付费的✌！

开发预算：¥0

@JecelynYeen 单⻚页应⽤用 (SPA) Firebase 寄存 (Free) ⽆无数据库 (JSON) Start with
Blank (Angular CLI)

ng new ng-my --createApplication false ng generate application site2019 创建
blank workspace 创建 application

12 SEO优化

@JecelynYeen

<title>July 06-07 | NG-MY 2019</title> <meta name="description" content="NG-MY 2019..."> <meta
property="og:url" content="https://2019.ng-my.org/" /> <meta property="og:description" content="NG-MY 2019..."> <meta property="og:type" content="website" /> <meta property="og:title" content="..." /> <meta property="og:image" content="img.png" /> <meta name="twitter:card" content="summary_large_image"> <meta name="twitter:image" content="img.png"> Title tag & Meta tags are essential for SEO

constructor(private title: Title, private meta: Meta) {} setPageMeta(title: string, metaDesc:
string, metaImg: string) { this.title.setTitle(title); this.meta.updateTag({ property: 'og:title', content: title }); this.meta.updateTag({ name: 'description', content: metaDesc }); this.meta.updateTag({ name: 'twitter:image', content: metaImg }); ... } export class PageService { } Utilize the built-in Title & Meta Service Set page title Update meta tag Inject title & meta services

Dev 开发环境 (No crawling) Prod ⽣生成环境 (Allow crawling) Robots.txt 协议
- To crawl or not to crawl? robots.txt robots.prod.txt

... "architect": { "build": { "assets": [ ..., "projects/site2019/src/robots.txt" ]
... } } angular.json Include robots.txt as output assets

"configurations": { "production": { "fileReplacements": [ ... { "replace": "projects/site2019/src/robots.txt",
"with": "projects/site2019/src/robots.prod.txt" } ] } } Replace file in angular.json Environment name Replace when env = production ng build -c production, or ng build --prod

@JecelynYeen 为啥还是不不work呢!?!

SEO Problem in SPA <html> <head> <script src="bundle.js"> </head> ...
</html> 伺服器器 sends HTML to 浏览器器 (No meta tags) <html> <head> <title>home</title> <meta ...> <script src="bundle.js"> </head> ... </html> 浏览器器 executes JS and add title & meta tags (too late!) Most crawlers only understand this. :(

@JecelynYeen Solution 构建时预渲染 Prerendering during build time

Brief: Angular Application Build Process (CLI) ng build --prod Generate
& Optimize files - js, css, etc Generate index.html Webpack Index transform We can extend & customize these!

Solution: Prerendering during build time ng build --prod Generate &
Optimize files - js, css, etc Open browser Browse & Save each route as .html Deploy all files to server Generate static html pages = Prerendering Generate index.html

Optimize files - js, css, etc Deploy all files to server Automate Prerendering using Puppeteer Generate index.html Program Puppeteer Browse & Save each route as .html

Puppeteer 前端神器器 - Programmable Chrome Browser const puppeteer = require('puppeteer');
(async () => { })(); const fs = require('fs').promises; await fs.writeFile('food.html', html, 'utf-8'); await browser.close(); await page.goto('https://ng-my.org/food', { waitUntil: ‘networkidle0'}); const html = await page.content(); const browser = await puppeteer.launch(); const page = await browser.newPage();

Optimize files - js, css, etc Program Puppeteer Browse & Save each route as .html Deploy all files to server Generate index.html Extend Angular CLI to customize this step Find an even easier library to help us!

Extend Angular CLI to handle Prerendering npm install -D @angular-builders/custom-webpack
npm install -D prerender-xs Extend Angular CLI Library to prerender with Puppeteer https://github.com/just-jeb/angular-builders https://github.com/chybie/prerender-xs

const Prerenderer = require('prerender-xs'); const routes = ['/food', '/team', '/speakers',
...]; index-html-transform.js Update angular.json to use this custom file module.exports = async (targetOptions, indexHtml) => { } const data = await Prerenderer.render({ staticDir: 'dist/site2019', routes, indexHtml }); return data.find(x => x.route === '/').html;

Sitemap is good to have https://support.google.com/webmasters/answer/156184?hl=en

Generate Sitemap Automatically ng build --prod Generate & Optimize files
- js, css, etc Deploy all files to server Generate sitemap.xml Extend Angular CLI Webpack to do so Generate index.html

Extend Angular CLI for Sitemap Generation npm install -D create-file-webpack
https://github.com/Appius/create-file-webpack Webpack plugin to create file (any format)

module.exports = { plugins: [ new CreateFileWebpack({ path: 'dist/site2019', fileName:
'sitemap.xml', content: generateSitemap(routes) })] } const CreateFileWebpack = require('create-file-webpack'); const routes = ['/food', '/team', '/speakers', ...] extra-webpack.config.js Our custom method to generate sitemap

33 提⾼高性能

遇到⻳龟速⽹网⻚页的⽆无奈奈…

@JecelynYeen Page Speed matters to SEO Ranking https://developers.google.com/web/updates/ 2018/07/search-ads-speed

http://bit.ly/mobile-page-weight Page Weight (Mobile)

@JecelynYeen ➔不不劳⽽而获* ➔图⽚片 ➔JavaScript ➔字体

@JecelynYeen 不不劳⽽而获*

@JecelynYeen ➔ 压缩丑化 Uglify (CLI) ➔ 事前编译 AOT (CLI) ➔
GZIP (Firebase) ➔ 差异化加载Differential Loading (CLI) Performance Optimization we get for FREE! ng build --prod

差异化加载能节省7-20% 的捆绑包⼤大⼩小现代浏览器器旧版浏览器器 Minimal polyfill Modern syntax Full
polyfill ES5 syntax

缓存静态资源 Cache Static Assets

{ "hosting": { "headers": [{ "source": "**/*.@(js|css|jpg|jpeg|gif|png|webp|svg)", "headers": [{ "key":
"Cache-Control", "value": "max-age=31536000" }] }], ... }, } Efficient cache (firebase.json) js, css, images longer cache

@JecelynYeen 图⽚片优化

5MB Images a page 流量量套餐

@JecelynYeen NPM: https://www.npmjs.com/package/svgo UI: https://jakearchibald.github.io/svgomg/ Optimize SVG with SVGOMG 32kb
-> 2kb (867B gzip)

@JecelynYeen WebP Images are 25-35% smaller than equivalent JPEG 0r
PNG.

78% Global User WebP has Arrived Based on data from
caniuse Source: bit.ly/webp-support Supported Supported Supported

.png - 119 kb .webp - 28 kb .png -
278 kb .webp - 30 kb

Serve WebP and support browsers <picture> <source srcset="拉茶.webp" type="image/webp"> <img
src=“拉茶.png"> </picture> Image container If browser supports WebP Else PNG it is

图⽚片压缩 Lossy Image For most images, 80-85% quality will reduce
file size by 30-40% with minimal effect on image quality.

495 kb 180 kb (80% quality) 图⽚片压缩 Lossy Image

Image in desktop & tablet can be ~2-4x larger than
mobile 28 kb 12 kb 响应式图⽚片 Responsive Images

Serve different image sizes <picture> <source media="(max-width: 800px)" srcset=“拉茶⼩小.webp" type="image/webp">
<source srcset="拉茶.webp" type="image/webp"> <img src="拉茶.png" > </picture> Small screen and if browser supports WebP https://developer.mozilla.org/en-US/docs/Learn/ HTML/Multimedia_and_embedding/ Responsive_images

@JecelynYeen squoosh.app resize, compress, format Or automate with these npm
packages: imagemin, sharp, jimp

@JecelynYeen Native lazy loading Defer fetching offscreen images / iframes
until a user scrolls near them. Load when scrolling down

image / iframe lazy load <picture> ... <img src="teh-tarik.png" loading="lazy">
</picture> <iframe src="https://www.youtube.com/embed/RYUPiv_lRFI" loading="lazy"> </iframe> https://developer.mozilla.org/en-US/docs/Learn/ HTML/Multimedia_and_embedding/ Add lazy loading attribute

Performant Images ➔Appropriate format 格式 ➔Appropriate compression 压缩 ➔Appropriate display
size 体积 ➔Is lazy 懒加载

JavaScript

倘若能瞬间消灭⼀一半的js files...

延迟加载 Lazy Loading 旧式 SPA (Eager Load) - big-bundle.js (60kb)
现代 SPA (Split & Lazy Load) - route-speakers.js (20kb) - route-food.js (20kb) - route-schedule.js (20kb) - ….

Lazy Loading 1-2 pages per module const routes: Routes =
[ { path: 'speakers', loadChildren: () => import('./speakers/speakers.module') .then(m => m.SpeakersModule) }, ... ]; Latest Angular version 8 syntax

Defer JavaScript <script> <script defer> HTML parsing HTML parsing paused
Script download Script execution

Defer 3rd party libraries <script defer src="https://www.googletagmanager.com/gtag/js?id=xxx"> </script> <script> ...
</script> Defer it Reduction of domComplete time

@JecelynYeen 字体

Display Font Immediately By default, if a font is not
loaded, The browser will hide text for up to:

Flash of Unstyled Text (FOUT) @font-face { font-family: Source Sans
Pro', sans-serif; src: url('...') format('woff'); font-display: swap; } Display unstyled text until font loaded .5s improvement in “Visual Complete” on 3G

fonts.googleapis.com/css? family=Source+Sans+Pro&display=swap

icomoon.io 减低图标体积 13 icons - 3.7kb

@JecelynYeen -猜猜⽹网⻚页最终体积-

343 kb 268 kb 结果 Result (ng-my.org)

⽹网站性能测试⼯工具 Lighthouse | Web Page Test | PageSpeed Insights

⽹网⻚页 (Web) ⽹网⻚页超能战⼠士 (We)

Make the Web Better for E.V.E.R.Y.O.N.E

谢谢⼤大家！我有贴纸。 @JecelynYeen 推特 / 微信 github: github.com/chybie/ng-my slides: bit.ly/ng-my-site video:
youtu.be/6l779_V4LV8 Instagram or FB me! @ngmykia

如何打造高性能且SEO友好的单页应用(SPA)

如何打造高性能且SEO友好的单页应用(SPA)

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