autolinker

What is autolinker?

Autolinker is a utility for automatically linking URLs, email addresses, phone numbers, and social media handles in plain text. It transforms these elements into clickable links, making it easier to navigate and interact with text content.

What are autolinker's main functionalities?

Link URLs

Automatically converts URLs in the text into clickable links.

const Autolinker = require('autolinker');
const linkedText = Autolinker.link('Check out this website: www.example.com');
console.log(linkedText); // 'Check out this website: <a href="http://www.example.com" target="_blank">www.example.com</a>'

Link Email Addresses

Automatically converts email addresses in the text into clickable mailto links.

const Autolinker = require('autolinker');
const linkedText = Autolinker.link('Contact us at [e-mail]');
console.log(linkedText); // 'Contact us at <a href="mailto:[e-mail]">[e-mail]</a>'

Link Phone Numbers

Automatically converts phone numbers in the text into clickable tel links.

const Autolinker = require('autolinker');
const linkedText = Autolinker.link('Call us at 123-456-7890');
console.log(linkedText); // 'Call us at <a href="tel:[phone]">123-456-7890</a>'

Link Social Media Handles

Automatically converts social media handles in the text into clickable links to the respective social media profiles.

const Autolinker = require('autolinker');
const linkedText = Autolinker.link('Follow us on Twitter @example');
console.log(linkedText); // 'Follow us on Twitter <a href="https://twitter.com/example" target="_blank">@example</a>'

Other packages similar to autolinker

linkifyjs

LinkifyJS is a versatile library for finding and converting URLs, email addresses, and hashtags in plain text into clickable links. It offers more customization options compared to Autolinker, such as custom link types and formats.

anchor-js

AnchorJS is a lightweight library that adds anchor links to headings in your HTML content. While it focuses on a different use case than Autolinker, it provides a simple way to enhance navigation within a document.

linkify-it

Linkify-it is a fast and lightweight library for finding and converting URLs in plain text into clickable links. It is highly customizable and can be extended with plugins to support additional link types.

README

Autolinker.js

Because I had so much trouble finding a good autolinking implementation out in the wild, I decided to roll my own. It seemed that everything I found out there was either an implementation that didn't cover every case, or was just limited in one way or another.

So, this utility attempts to handle everything. It:

• Autolinks URLs, whether or not they start with the protocol (i.e. 'http://'). In other words, it will automatically link the text "google.com", as well as "http://google.com".
• Will properly handle URLs with special characters
• Will properly handle URLs with query parameters or a named anchor (i.e. hash)
• Will autolink email addresses.
• Will autolink Twitter handles.
• Will properly handle HTML input. The utility will not change the href attribute inside anchor (<a>) tags (or any other tag/attribute for that matter), and will not accidentally wrap the inner text of an anchor tag with a new one (which would cause doubly-nested anchor tags).

Hope that this utility helps you as well!

Installation

Download

Simply clone or download the zip of the project, and link to either dist/Autolinker.js or dist/Autolinker.min.js with a script tag:

<script src="path/to/Autolinker.min.js"></script>

Using with the Bower package manager:

Command line:

bower install Autolinker.js --save

Using with Node.js via npm:

Command Line:

npm install autolinker --save

JavaScript:

var Autolinker = require( 'autolinker' );
// note: npm wants an all-lowercase package name, but the utility is a class and should be 
// aliased with a captial letter

Usage

Using the static link() method:

var linkedText = Autolinker.link( textToAutolink[, options] );

Using as a class:

var autolinker = new Autolinker( [ options ] );

var linkedText = autolinker.link( textToAutoLink );

Note: if using the same options to autolink multiple pieces of html/text, it is slightly more efficient to create a single Autolinker instance, and run the link() method repeatedly (i.e. use the "class" form above).

Example:

var linkedText = Autolinker.link( "Check out google.com", { className: "myLink" } );
// Produces: "Check out <a class="myLink myLink-url" href="http://google.com" target="_blank">google.com</a>"

Options

These are the options which may be specified for linking. These are specified by providing an Object as the second parameter to Autolinker.link(). These include:

• newWindow : Boolean
  true to have the links should open in a new window when clicked, false otherwise. Defaults to true.
  
  

• stripPrefix : Boolean
  true to have the 'http://' or 'https://' and/or the 'www.' stripped from the beginning of links, false otherwise. Defaults to true.
  
  

• truncate : Number
  A number for how many characters long URLs/emails/twitter handles should be truncated to inside the text of a link. If the URL/email/twitter is over the number of characters, it will be truncated to this length by replacing the end of the string with a two period ellipsis ('..').
  
  Example: a url like 'http://www.yahoo.com/some/long/path/to/a/file' truncated to 25 characters may look like this: 'yahoo.com/some/long/pat..'
  

• className : String
  A CSS class name to add to the generated anchor tags. This class will be added to all links, as well as this class plus "url"/"email"/"twitter" suffixes for styling url/email/twitter links differently.

  For example, if this config is provided as "myLink", then:

  1. URL links will have the CSS classes: "myLink myLink-url"
     
  2. Email links will have the CSS classes: "myLink myLink-email", and
     
  3. Twitter links will have the CSS classes: "myLink myLink-twitter"
     

• urls : Boolean
  true to have URLs auto-linked, false to skip auto-linking of URLs. Defaults to true.
  

• email : Boolean
  true to have email addresses auto-linked, false to skip auto-linking of email addresses. Defaults to true.
  
  

• twitter : Boolean
  true to have Twitter handles auto-linked, false to skip auto-linking of Twitter handles. Defaults to true.

• replaceFn : Function
  A function to use to programmatically make replacements of matches in the input string, one at a time. See the section Custom Replacement Function for more details.

For example, if you wanted to disable links from opening in new windows, you could do:

var linkedText = Autolinker.link( "Check out google.com", { newWindow: false } );
// Produces: "Check out <a href="http://google.com">google.com</a>"

And if you wanted to truncate the length of URLs (while also not opening in a new window), you could do:

var linkedText = Autolinker.link( "http://www.yahoo.com/some/long/path/to/a/file", { truncate: 25, newWindow: false } );
// Produces: "<a href="http://www.yahoo.com/some/long/path/to/a/file">yahoo.com/some/long/pat..</a>"

More Examples

One could update an entire DOM element that has unlinked text to auto-link them as such:

var myTextEl = document.getElementById( 'text' );
myTextEl.innerHTML = Autolinker.link( myTextEl.innerHTML );

Using the same pre-configured Autolinker instance in multiple locations of a codebase (usually by dependency injection):

var autolinker = new Autolinker( { newWindow: false, truncate: 25 } );

//...

autolinker.link( "Check out http://www.yahoo.com/some/long/path/to/a/file" );
// Produces: "Check out <a href="http://www.yahoo.com/some/long/path/to/a/file">yahoo.com/some/long/pat..</a>"

//...

autolinker.link( "Go to www.google.com" );
// Produces: "Go to <a href="http://www.google.com">google.com</a>"

Custom Replacement Function

A custom replacement function (replaceFn) may be provided to replace url/email/twitter matches on an individual basis, based on the return from this function.

Full example, for purposes of documenting the API:

var input = "...";  // string with URLs, Email Addresses, and Twitter Handles

var linkedText = Autolinker.link( input, {
    replaceFn : function( autolinker, match ) {
    	console.log( "href = ", match.getAnchorHref() );
    	console.log( "text = ", match.getAnchorText() );
    
        switch( match.getType() ) {
        	case 'url' : 
        		console.log( "url: ", match.getUrl() );
        		
        		if( match.getUrl().indexOf( 'mysite.com' ) === -1 ) {
        			var tag = autolinker.getTagBuilder().build( match );  // returns an `Autolinker.HtmlTag` instance, which provides mutator methods for easy changes
        			tag.setAttr( 'rel', 'nofollow' );
        			tag.addClass( 'external-link' );
        			
        			return tag;
        			
        		} else {
        			return true;  // let Autolinker perform its normal anchor tag replacement
        		}
        		
        	case 'email' :
        		var email = match.getEmail();
        		console.log( "email: ", email );
        		
        		if( email === "[e-mail]" ) {
        			return false;  // don't auto-link this particular email address; leave as-is
        		} else {
        			return;  // no return value will have Autolinker perform its normal anchor tag replacement (same as returning `true`)
        		}
        	
        	case 'twitter' :
        		var twitterHandle = match.getTwitterHandle();
        		console.log( twitterHandle );
        		
        		return '<a href="http://newplace.to.link.twitter.handles.to/">' + twitterHandle + '</a>';
        }
    }
} );

The function is provided two arguments:

1. The Autolinker instance that is performing replacements. This can be used to query the options that the Autolinker instance is configured with, or to retrieve its TagBuilder instance (via autolinker.getTagBuilder()).
2. An Autolinker.match.Match object which details the match that is to be replaced.

A replacement of the match is made based on the return value of the function. The following return values may be provided:

• No return value (undefined), or true (Boolean): Delegate back to Autolinker to replace the match as it normally would.
• false (Boolean): Do not replace the current match at all - leave as-is.
• Any String: If a string is returned from the function, the string will be used directly as the replacement HTML for the match.
• An Autolinker.HtmlTag instance, which can be used to build/modify an HTML tag before writing out its HTML text.

Changelog:

0.12.1

• Expose the Autolinker.HtmlTag class, and allow it to be used in the replaceFn

0.12.0

• Add replaceFn option

0.11.0

• Allow Autolinker to link fully-capitalized URLs/Emails/Twitter handles.

0.10.1

• Added fix to not autolink strings like "version:1.0", which were accidentally being interpreted as a protocol:domain string.

0.10.0

• Added support for protocol-relative URLs (ex: //google.com, which will effectively either have the http:// or https:// protocol depending on the protocol that is hosting the website)

0.9.4

• Fixed an issue where a string in the form of abc:def would be autolinked as a protocol and domain name URL. Autolinker now requires the domain name to have at least one period in it to be considered.

0.9.3

• Fixed an issue where Twitter handles wouldn't be autolinked if they existed as the sole entity within parenthesis or brackets (thanks @busticated for pointing this out and providing unit tests)

0.9.2

• Fixed an issue with nested tags within an existing <a> tag, where the nested tags' inner text would be accidentally removed from the output (thanks @mjsabin01)

0.9.1

• Added a patch to attempt to better handle extraneous </a> tags in the input string if any exist. This is for when the input may have some invalid markup (for instance, on sites which allow user comments, blog posts, etc.).

0.9.0

• Added better support for the processing of existing HTML in the input string. Now handles namespaced tags, and attribute names with dashes or any other Unicode character (thanks @aziraphale)

0.8.0

• Added className option for easily styling produced links (thanks @busticated)
• Refactored into a JS class. Autolinker can now be instantiated using:

var autolinker = new Autolinker( { newWindow: false, truncate: 25 } );

autolinker.link( "Check out http://www.yahoo.com/some/long/path/to/a/file" );
// Produces: "Check out <a href="http://www.yahoo.com/some/long/path/to/a/file">yahoo.com/some/long/pat..</a>"

This allows options to be set on a single instance, and used throughout a codebase by injecting the autolinker instance as a dependency to the modules/classes that use it. (Note: Autolinker may still be used with the static Autolinker.link() method as was previously available as well.)

0.7.0

• Changed build system to Grunt.
• Added AMD and CommonJS module loading support (ex: RequireJS, and Node.js's module loader).
• Added command line Jasmine test runner (grunt test)
• Upgraded Jasmine from 1.3.1 to 2.0
• Added license header to dist files.

(Thanks to @busticated!)

0.6.1

• Added LICENSE file to repository.

0.6.0

• Added options for granular control of which types are linked (urls, email addresses, and/or twitter handles). (thanks @aziraphale)

0.5.0

• Simplified the path / query string / hash processing into a single regular expression instead of 3 separate ones.
• Added support for parenthesis in URLs, such as: en.wikipedia.org/wiki/IANA_(disambiguation) (thanks @dandv)
• Add all known top-level domains (TLDs) (thanks @wouter0100)

0.4.0

Merged pull requests from @afeld:

• strip protocol and 'www.' by default - fixes #1
• truncate URLs from the end
• make simpler regex for detecting prefix
• remove trailing slashes from URLs, and handle periods at the end of paths
• re-use domain+TLD regexes for email matching
• add .me and .io to list of TLDs

Thanks Aidan :)

0.3.1

• Fixed an issue with handling nested HTML tags within anchor tags.

0.3

• Implemented the truncate option.

0.2

• Implemented autolinking Twitter handles.

0.1

• Initial implementation, which autolinks URLs and email addresses. Working on linking Twitter handles.