express-middleware-seo's Introduction

express-middleware-seo

SEO middleware for express base on chrome-render, a substitute for prerender.

Modern web app use technique like react.js vue.js which render html in browser, this lead to search engine can't crawl your page content.

This project want to solve this kind of problem in a general-purpose way, it detect request is from search engine crawler then use headless chrome to render out your modern web page and return to crawler.

Here is express-middleware-seo's architecture diagram:

Use

npm i express-middleware-seo

then use it:

const express = require('express')
const path = require('path')
const app = express()
const { seoMiddleware } = require('express-middleware-seo')

app.use(
  seoMiddleware({
    enable: true,
    render: {
      useReady: true,
      renderTimeout: 10000
    }
  })
)

app.use(express.static(__dirname + '/static'))

app.listen(3000)

you can download and run this complete demo

Notice

You should install Chrome 59+ in your servers before you use this middleware

Options

options come form chrome-render

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.
renderTimeout: number in ms, chromeRender.render() will throw error if html string can't be resolved after renderTimeout, default is 5000ms.
useReady: boolean whether use window.isPageReady=1 to notify chrome-render page has 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