chrome-render

High-performance and universal server render base on Headless chrome, render any SPA(render data in browser) in server for SEO or other optimizes.

Use

1. install it from npm by npm i chrome-render

2. new a ChromeRender then use it to render a web page, a ChromeRender means a chrome.

   const ChromeRender = require('chrome-render');
   // ChromeRender.new() return a Promise, you can use async function in this way:
   // const chromeRender = await ChromeRender.new(); 
   ChromeRender.new({}).then(async(chromeRender)=>{
   const htmlString = await chromeRender.render({
      url: 'http://qq.com',
   });
   });    

   A chromeRender instance can call render multi-times and concurrent for high frequency use case. chromeRender will manage a tabs pool to render multi-pages concurrent.

3. After you don't need chromeRender anymore, you should call await chromeRender.destroyRender() to kill chrome add release all resource.

see more demo in unit test

API

ChromeRender.new() method support options:

• maxTab: number max tab chrome will open to render pages, default is no limit, maxTab used to avoid open to many tab lead to chrome crash. ChromeRender will create a tab poll to reuse tab for performance improve and resource reduce as open and close tab in chrome require time, like database connection poll.
• chromeRunnerOptions: object same as chrome-runner's options, can config chrome's startup options, detail see chrome-runner options

chromeRender.render() method support options:

• url: string is required, web page's URL
• cookies: object {cookieName:cookieValue} is an option param. set HTTP cookies when request web page
• headers: object {headerName:headerValue} is an option param. add HTTP headers when request web page
• useReady: boolean whether use window.isPageReady=1 to notify chrome-render page is ready. default is false chrome-render use domContentEventFired as page has ready.
• script: string is an option param. inject script source to evaluate when page on load
• renderTimeout: number in ms, render() will throw error if html string can't be resolved after renderTimeout, default is 5000ms.
• deviceMetricsOverride: object overrides the values of device screen dimensions for responsive websites, detail use see here
• clearTab: boolean if true after render chrome instance will navigate to about:blank to free resources. default is true. setting to false may increase page load speed when rendering the same website.

all request from chrome-render will take with a HTTP header x-chrome-render:${version}

Friends

• chrome-render dependent on chrome-pool headless chrome tabs manage pool.
• chrome-runner run chrome with nodejs in code.
• koa-chrome-render chrome-render middleware for koa.
• koa-seo SEO middleware for koa base on chrome-render substitute for prerender.