This is a node server that uses phantomjs to render a javascript-rendered page as HTML.
It should be used in conjunction with these middleware libraries to serve the prerendered HTML to crawlers for SEO. Facebook and Twitter also crawl the prerendered HTML when someone posts a link to your site on their social network. You don't have to run this service on your own since I have it deployed on Heroku already. Get started in two lines of code using Rails or Node.
This service also adheres to google's _escaped_fragment_ proposal for AJAX calls if you use it on your website.
It is also meant to be proxied through your server so that any relative links to things like CSS will work.
It is currently deployed at http://prerender.herokuapp.com, or you can deploy your own.
$ git clone https://github.com/collectiveip/prerender.git
$ heroku create
$ git push heroku master
If you are running the prerender service locally. Make sure you set your middleware to point to your local instance with:
export PRERENDER_SERVICE_URL=<your local url>
Otherwise, it will 404 and your normal routing will take over and render the normal JS page.
$ npm install
$ node index.js
// also supports heroku style invocation using foreman
$ foreman start
This is a simple service that only takes a url and returns the rendered HTML (with all script tags removed).
Note: you should proxy the request through your server so that relative links to CSS still work (see prerender_rails or prerender-node for an example)
GET http://prerender.herokuapp.com/https://google.com
GET http://prerender.herokuapp.com/https://google.com/search?q=angular
We use a plugin system in the same way that Connect and Express use middleware. Our plugins are a little different and we don't want to confuse the prerender plugins with the prerender middleware, so we opted to call them "plugins".
Plugins are in the lib/plugins directory, and add functionality to the prerender service.
Each plugin can implement any of the 3 plugin methods:
####init = function(){}
init is called when you call prerender.use(require('my_plugin'));.
Use this function to initialize defaults.
####beforePhantomRequest = function(req, res, next){}
beforePhantomRequest is called at the beginning of the request lifecycle, before phantomjs starts to load the url.
Use this function to short circuit the lifecycle.
Examples:
- Find and return a cached version of the url before loading it.
- Reject a request based on the host sending too many requests per second.
####afterPhantomRequest = function(req, res, next){}
afterPhantomRequest is called at the end of the request lifecycle, after phantomjs successfully loads the HTML for a url.
Use this function to access/modify the HTML returned from a url.
Examples:
- Save off the HTML to a cache for quick access later.
- Change the HTML to remove all script tags.
console.log(req.prerender);
{
//the url that will be hit (transformed from _escaped_fragment_ if passed in)
url: 'http://site.com/#!/path/to/a/site',
//the HTML that came back from the webpage (only in afterPhantomRequest)
documentHTML: '<html></html>'
}We remove script tags because we don't want any framework specific routing/rendering to happen on the rendered HTML once it's executed by the crawler. The crawlers may not execute javascript, but we'd rather be safe than have something get screwed up.
For example, if you rendered the HTML of an angular page but left the angular scripts in there, your browser would try to execute the angular routing and rendering on a page that no longer has any angular bindings.
We use cache management to reduce the latency on common requests
The default is an in memory cache but you can easily change it to any caching system compatible with the cache-manager nodejs package.
For example, with the request:
GET http://prerender.herokuapp.com/https://facebook.com
First time: Overall Elapsed: 00:00:03.3174661
With cache: Overall Elapsed: 00:00:00.0360119
By default, cache system isn't enabled, you need to uncomment it in index.js to enable it.
This is a list of middleware available to use with the prerender service:
- prerender-node (Express)
- prerender_rails (Rails)
- zfr-prerender (Zend Framework 2)
- YuccaPrerenderBundle (Symfony 2)
Request more middleware for a different framework in this issue.
The MIT License (MIT)
Copyright (c) 2013 Todd Hooper <todd@collectiveip.com>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.