linkify-it-rb

Gem Version

Links recognition library with full unicode support. Focused on high quality link pattern detection in plain text. For use with both Ruby and RubyMotion.

This gem is a port of the linkify-it javascript package by Vitaly Puzrin, that is used for the markdown-it package.

Javascript Demo

Features:

  • Full unicode support, with astral characters
  • International domain support
  • Allows rules extension & custom normalizers

Install

Ruby

Add it to your project's Gemfile

gem 'linkify-it-rb'

and run bundle install

RubyMotion

Add it to your project's Gemfile

gem 'linkify-it-rb'

Edit your Rakefile and add

require 'linkify-it-rb'

and run bundle install

Usage examples

Example 1
linkify = Linkify.new

# add unoffocial `.mydomain` domain.
linkify.tlds('.mydomain', true)  # Add unofficial `.mydomain` domain
linkify.add('git:', 'http:')     # Add `git:` ptotocol as "alias"
linkify.add('ftp:', null)        # Disable `ftp:` ptotocol

linkify.test('Site github.com!'))
=> true

linkify.match('Site github.com!'))
=> [#<Linkify::Match @schema="", @index=5, @lastIndex=15, @raw="github.com", @text="github.com", @url="github.com">]
Exmple 2. Add twitter mentions handler
linkify.add('@', {
  validate: lambda do |text, pos, obj|
    tail = text.slice(pos..-1)
    if (!obj.re[:twitter])
      obj.re[:twitter] =  Regexp.new('^([a-zA-Z0-9_]){1,15}(?!_)(?=$|' + LinkifyRe::SRC_Z_P_CC + ')')
    end
    if (obj.re[:twitter] =~ tail)
      return 0 if (pos >= 2 && text[pos - 2] == '@')
      return tail.match(obj.re[:twitter])[0].length
    end
    return 0
  end,
  normalize: lambda do |m, obj|
    m.url = 'https://twitter.com/' + m.url.sub(/^@/, '')
  end
})

API

LinkifyIt.new(schemas)

Creates new linkifier instance with optional additional schemas.

By default understands:

  • http(s)://... , ftp://..., mailto:... & //... links
  • "fuzzy" links and emails (google.com, [email protected]).

schemas is a Hash, where each key/value describes protocol/rule:

  • key - link prefix (usually, protocol name with : at the end, skype: for example). linkify-it-rb makes shure that prefix is not preceeded with alphanumeric char.
  • value - rule to check tail after link prefix
    • String - just alias to existing rule
    • Hash
    • validate - validator block (should return matched length on success), or RegExp.
    • normalize - optional block to normalize text & url of matched result (for example, for twitter mentions).

.test(text)

Searches linkifiable pattern and returns true on success or false on fail.

.pretest(text)

Quick check if link MAYBE can exist. Can be used to optimize more expensive .test calls. Return false if link can not be found, true - if .test call needed to know exactly.

.testSchemaAt(text, name, offset)

Similar to .test but checks only specific protocol tail exactly at given position. Returns length of found pattern (0 on fail).

.match(text)

Returns Array of found link matches or nil if nothing found.

Each match has:

  • schema - link schema, can be empty for fuzzy links, or // for protocol-neutral links.
  • index - offset of matched text
  • lastIndex - index of next char after mathch end
  • raw - matched text
  • text - normalized text
  • url - link, generated from matched text

.tlds(list[, keepOld])

Load (or merge) new tlds list. These are used for fuzzy links (without prefix) to avoid false positives. By default this algorithm uses:

  • hostname with any 2-letter root zones are ok.
  • biz|com|edu|gov|net|org|pro|web|xxx|aero|asia|coop|info|museum|name|shop|рф are ok.
  • encoded (xn--...) root zones are ok.

If list is replaced, then exact match for 2-chars root zones will be checked.

.add(schema, definition)

Add new rule with schema prefix. For definition details see constructor description. To disable existing rule use .add(name, nil)

License

MIT