linkie

linkie is a library that extracts meta information about a link.

npm install linkie --save

Example

const linkie = require('linkie');

linkie.fetch('https://arpitbhayani.me/techie/rest-the-hard-way-with-netcat.html', {}, (err, metadata) => {
    if (err) { return console.error(err) };
    console.log(metadata);
});

Output

{ url: 'https://arpitbhayani.me/techie/rest-the-hard-way-with-netcat.html',
  status: 200,
  host: 'arpitbhayani.me',
  title: 'HTTP Requests - The Hard Way with Netcat',
  description: 'All our lives we have been hitting REST APIs with libraries and utilities like curl and postman. Its time we do it the hard way with netcat, just for fun!',
  type: 'article',
  keywords:
   [ 'http-requests',
     'netcat',
     'calling rest api with netcat',
     'calling rest api from microcontroller',
     'http request messages' ],
  image: 'https://arpitbhayani.me/static/images/http-requests/http-request-hard-way-with-netcat.jpg' }

API

fetch(url, [options,] callback)

Explanation:

• url -> Full URL whose meta information is to be fetched
• options -> Options for the fetching
  • verifyImage -> After successfully extracting image about the link, linkie can also validate if image really exists or not. By default this option is disabled and hence linkie will not verify the image. But if you want to verify the image just pass {verifyImage: true} and linkie will make another request and verufy if image is valid or not. If image does not exist then metadata will not contain field image.
• callback(err, metadata)

Explain me the output

• url -> The URL that was fetched.
• status -> HTTP Response status code
• host -> Hostname from which response was served
• title -> Title of the page
• description -> Meta description about the link
• type -> type of the page that link points to
• keywords -> Meta keywords about the link
• image -> meta image about the link

Features

Video

If a youtube link is given then the metadata will contain field extra which will contain the video id in field vid that you can directly use to embed in Youtube Player.

{ url: 'https://www.youtube.com/watch?v=0cMCo7lyQoY',
  status: 200,
  host: 'www.youtube.com',
  title: 'Film Theory: Was SpongeBob ADOPTED?! (SpongeBob SquarePants)',
  description: 'SUBSCRIBE for More Film Theories! ► http://bit.ly/1dI8VBH You\'ll Die Before this Spongebob Meme ► http://bit.ly/2C3IkhT Gravity Falls ISN’T OVER! ►► http://b...',
  type: 'video',
  keywords:
   [ 'spongebob',
     'spongebob squarepants',
     'spongebob episodes',
     'spongebob full episodes',
     'spongebob live',
     'spongebob remix',
     'spongebob songs',
     'spongebob squarepants movie',
     '...' ],
  site: 'youtube',
  extra: { vid: '0cMCo7lyQoY' },
  image: 'https://i.ytimg.com/vi/0cMCo7lyQoY/maxresdefault.jpg' }

Meta information and where it fetches from

The meta information about the link contains several fields. There is a possibility that some information might not be present on the page, hence linkie tries its best to get information. There is fallback on all important fields. For each of the following fields the list represents the places it tries to fetch information from.

Title

• OG Title meta[property='og:title']
• <title> tag

Description

• OG Description meta[property='og:description']
• <meta[name='description']>
• All <p> tags, combined to minimum length of 128 characters.

Image

• OG Image meta[property='og:image']
• First image tag <img>

Keywords

• meta[name='keywords']

Type

• OG Type meta[property='og:type']

Setup a development environment

Make sure you have node and npm installed.

Install all the required dependencies

npm install

Start local development server

npm run dev

This will start a local development server that listens on file change and rebuilds everytime that file is changed.

See if everythign is working

In the repository you will find a file named basic.js, execute the file and see the output.

node tst/basic.js

You should now see the output that looks something like this

{ url: 'https://arpitbhayani.me/techie/rest-the-hard-way-with-netcat.html',
  status: 200,
  host: 'arpitbhayani.me',
  title: 'HTTP Requests - The Hard Way with Netcat',
  description: 'All our lives we have been hitting REST APIs with libraries and utilities like curl and postman. Its time we do it the hard way with netcat, just for fun!',
  type: 'article',
  keywords:
   [ 'http-requests',
     'netcat',
     'calling rest api with netcat',
     'calling rest api from microcontroller',
     'http request messages' ],
  image: 'https://arpitbhayani.me/static/images/http-requests/http-request-hard-way-with-netcat.jpg' }