MongoidShortener is a gem that has to be used together with Mongoid to shorten URLs. It uses the yab62 gem to convert URLs to base 62 shortened link.

It is based on Rails engine. I have only tested this on Rails 3.1. You might have problem using with Rails version less than 3.1.

To use MongoidShortener, first you have to install the gem.

# Gemfile
gem "mongoid_shortener"
gem "yab62", require: "yab62"
# Terminal
bundle install

After that, make sure that you have set the MongoidShortener's root_url and prefix_url, you can do this like the following:

# /config/initializers/mongoid_shortener.rb
MongoidShortener.root_url = "http://dailymus.es"
MongoidShortener.prefix_url = "http://dailymus.es/~"

root_url is the url that gets redirected to if no matched shortened url is found.

prefix_url is the url get prefixed to the unique_key after the base 62 conversion. For example, if the link http://google.com gets converted to xYAwc. The returned link will be http://dailymus.es/~xYAwc for the above example code.

To use MongoidShortener in your project, it provides you with two simple helper functions. One is for internal use and another one is the view helper.

MongoidShortener.root_url = "http://dailymus.es"
MongoidShortener.prefix_url = "http://dailymus.es/~"

# helper function
MongoidShortener.generate("http://google.com") # -> "http://dailymus.es/~xYAwc"

# view helper function
shortened_url("http://google.com") # -> "http://dailymus.es/~xYAwc"

Besides that, MongoidShortener also provides a really good helper controllor that you can make use of. To use it, add this particular route to your config/routes.rb

# config/routes.rb
match '/:unique_key' => 'mongoid_shortener/shortened_urls#translate', :via => :get, :constraints => { :unique_key => "~.+" }

What this basically does is that it creates a routes that will only match anything starts with /~. So, when theres is a request that hits that route, it will get redirect to the helper controller of MongoidShortener.

The controller code in fact looks like:

module MongoidShortener
  class ShortenedUrlsController < ApplicationController
    # find the real link for the shortened link key and redirect
    def translate
      # pull the link out of the db
      sl = ShortenedUrl.where(:unique_key => params[:unique_key][1..-1]).first

      if sl
        sl.inc(:use_count, 1)
        # do a 301 redirect to the destination url
        head :moved_permanently, :location => sl.url
      else
        # if we don't find the shortened link, redirect to the root
        # make this configurable in future versions
        head :moved_permanently, :location => MongoidShortener.root_url
      end
    end
  end
end

Let me know if you find any bug for this particular plugin.

Parts of the code are from the gem shortener.

(The MIT License)

Copyright (c) 2011 Teng Siong Ong

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.