Is there an open-source version of Facebook's Linter? - screen-scraping

Question

When you post a link to Facebook, it grabs the article title, description and relevant images. Most major sites have the required OG tags, making it easy to grab this info, but FB is also able to handle websites that don't have them (you can try it here).
Clearly they've got a system in place for grabbing this info in the absence of OG tags. Does anyone know if there's an open-source version?
I'm thinking it would need (in order of preference for each section):
Title:
Check for og:title tag.
Check for regular meta "title" tag.
Check for h1 tag.
Description:
Check for og:description tag.
Check for regular meta "description tag"
Check for div or p tags with sufficient content to indicate a body paragraph
Images:
Check for og:image tags
Check for images over a certain size (say 100x100) and give priority to those that come first.
Thanks a lot!

Answer 1

https://github.com/Anonyfox/node-htmlcarve
The htmlcarve module for Node.js does most of what you're after, here's the output generated from this page:
htmlcarve = require('htmlcarve');
htmlcarve.fromUrl('https://scotch.io/tutorials/using-mongoosejs-in-node-js-and-mongodb-applications', function(error, data) {
console.log(JSON.stringify(data, null, 2));
});
This produces:
{
"source": {
"html_meta": {
"title": "Easily Develop Node.js and MongoDB Apps with Mongoose ⥠Scotch",
"summary": "",
"image": "/wp-content/themes/thirty/img/scotch-logo.png",
"language": "en-US",
"feed": "https://scotch.io/feed",
"favicon": "https://scotch.io/wp-content/themes/thirty/img/icons/favicon-57.png",
"author": "Chris Sevilleja"
},
"open_graph": {
"title": "Easily Develop Node.js and MongoDB Apps with Mongoose",
"summary": "",
"image": "https://scotch.io/wp-content/uploads/2014/11/mongoosejs-node-mongodb-applications.png"
},
"twitter_card": {
"title": "Easily Develop Node.js and MongoDB Apps with Mongoose",
"summary": "",
"author": "sevilayha"
}
},
"result": {
"title": "Easily Develop Node.js and MongoDB Apps with Mongoose",
"summary": "",
"image": "https://scotch.io/wp-content/uploads/2014/11/mongoosejs-node-mongodb-applications.png",
"author": "sevilayha",
"language": "en-US",
"feed": "https://scotch.io/feed",
"favicon": "https://scotch.io/wp-content/themes/thirty/img/icons/favicon-57.png"
},
"links": {
"deep": "https://scotch.io/tutorials/using-mongoosejs-in-node-js-and-mongodb-applications",
"shallow": "https://scotch.io/tutorials/using-mongoosejs-in-node-js-and-mongodb-applications",
"base": "https://scotch.io"
}
}
If you've got Node.js installed, then install it using
npm i -g htmlcarve
and you can run it from the command line directly.