Prerender is a node server that uses Headless Chrome to render HTML, screenshots, PDFs, and HAR files out of any web page. The Prerender server listens for an http request, takes the URL and loads it in Headless Chrome, waits for the page to finish loading by waiting for the network to be idle, and then returns your content.

Use

• yarn install or npm install It will install dependencies.
• yarn start or npm start It will run chrome server.

How Works

Farmy prerender only works with farmy_prerender gem that should be stay in vendor/gems/farmy_prerender configured in config/initializers/prerender.rb When request, the gem check if is a robot or if parameter is passed, when result is true, it send http call chrome server. Chrome server check if a redis key exists and if exists it will be response with it. if it does not exist, it will respond with a json that contains prerendering: true and will start asynchronously the rendering of the p it will initialize rendering process. Now you can pass a param using _force_rendered_:

• clear: Always will serve a rendered version even if there's one cached.

Options

Chrome Server

In server.js file you can specify several options.

Rails Middleware

In prerender.rb you can setup:

• render_server (string): url where chrome server is running.
• host (string): url that chrome server use to request page to render. It can be the same that farmy instance.
• default_render_robot (bool): If it is true the server will respond with a rendered page as long as it detects that it is a robot, on the other hand if it is false, it will only respond with a rendered view if the parameter force_rendered is passed.