amogil / url_regex

Provides the best regex for validating or extracting URLs

UrlRegex

Provides the best known regex for validating and extracting URLs. It builds on amazing work done by Diego Perini and Mathias Bynens.

Why do we need a gem for this regex?

• You don't need to follow changes and improvements of original regex.
• You can slightly customize the regex: a scheme can be optional, and you can get the regex for validation or parsing.

Installation

Add this line to your application's Gemfile:

gem 'url_regex'

And then execute:

$ bundle

Or install it yourself as:

$ gem install url_regex

Usage

Get the regex:

UrlRegex.get(options)

where options are:

• scheme_required indicates that schema is required, defaults to true.

• mode can gets either :validation, :parsing or :javascript, defaults to :validation.

:validation asks to return the regex for validation, namely, with \A prefix, and with \z postfix. That means, it matches whole text:

UrlRegex.get(mode: :validation).match('https://www.google.com').nil?
# => false
UrlRegex.get(mode: :validation).match('link: https://www.google.com').nil?
# => true

:parsing asks to return the regex for parsing:

str = 'links: google.com https://google.com?t=1'
str.scan(UrlRegex.get(mode: :parsing))
# => ["https://google.com?t=1"]

# schema is not required
str.scan(UrlRegex.get(scheme_required: false, mode: :parsing))
# => ["google.com", "https://google.com?t=1"]

:javascript asks to return the regex formatted for use in Javascript files or as pattern attribute values on HTML inputs. For this purpose, you'd use the source method on the Regexp object instance in order to produce a string that Javascript will understand. These examples make use of the Rails text_field method to generate HTML input elements.

regex = UrlRegex.get(mode: :javascript)
text_field(:site, :url, pattern: regex.source)
# => <input type="text" id="site_url" name="site[url]" pattern="[javascript URL regex]" />

regex = UrlRegex.get(scheme_required: false, mode: :javascript)
text_field(:site, :url, pattern: regex.source)
# => <input type="text" id="site_url" name="site[url]" pattern="[javascript URL regex with optional scheme]" />

UrlRegex.get returns regular Ruby's Regex object, so you can use it as usual.

All regexes are case-insensitive.

FAQ

Q: Hey, I want to parse HTML, but it doesn't work:

str = '<a href="http://google.com?t=1">Link</a>'
str.scan(UrlRegex.get(mode: :parsing))
# => "http://google.com?t=1">Link</a>"

A: Well, you probably know that parsing HTML with regex is a bad idea. It requires matching corresponding open and close brackets, that makes the regex even more complicated.

Q: How can I speed up processing?

A: Generated regex depends only on options, so you can get the regex only once and cache it.

Contributing

1. Fork it ( https://github.com/[my-github-username]/url_regex/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request