Robby on Rails

We’ve been doing some early (or late… if you’re a half-full kind of person) spring cleaning on some of our projects. One of the small projects, flash_message_conductor, which we released last year as a plugin is now a gem. We’ve been moving away from using plugins in favor of gems as we like locking in specific released versions and being able to specify them in our environment.rb file is quite convenient.

To install, just run the following:

  sudo gem install flash-message-conductor --source=http://gemcutter.org
  Successfully installed flash-message-conductor-1.0.0
  1 gem installed
  Installing ri documentation for flash-message-conductor-1.0.0...
  Installing RDoc documentation for flash-message-conductor-1.0.0...

You’ll then just need to include the following in your config/environment.rb file.

Rails::Initializer.run do |config|
  # ...
  config.gem 'flash-message-conductor', :lib => 'flash_message_conductor', :source => "http://gemcutter.org"
end

You can take a peak at the README for usage examples.

We’ll be packaging up a handful of our various plugins that we reuse on projects and moving them to gems. Stay tuned… :-)

In my last post, Subdomain accounts with Ruby on Rails explaind, I mentioned that you’d need to modify your /etc/hosts file to use custom subdomains for development/testing. Apparently, there is a much better way to handle this that I was introduced to by Nathan de Vries. Nathan suggests using a gem that I hadn’t heard of before that bares the name of Ghost (view project on github).

Ghost describes itself as…

“A gem that allows you to create, list, and modify local hostnames in 10.5 with ease…”—

If you’ve ever had to modify your /etc/hosts file for anything local, I highly encourage you to check out this shiny gem.

Installing Ghost

Like most gems, you can just install Ghost with the following command.

~ : sudo gem install ghost
Password:
Successfully installed ghost-0.1.2-universal-darwin-9
1 gem installed
Installing ri documentation for ghost-0.1.2-universal-darwin-9...
Installing RDoc documentation for ghost-0.1.2-universal-darwin-9...

Okay, now that Ghost is installed, let’s see what we can do with it.

Using Ghost for local domains/subdomains

Ghost is fairly straight forward. It’s essentially a friendly wrapper for dscl, which is the Directory Service command line utility for Mac OS X. I’ve never played with that directly, but it seems that with Ghost… I shouldn’t need to. :-)

With Ghost, you can add, modify, and delete entries in the Directory Service by issuing any of the following commands. Let’s start out by running ghost to see what we have here.

 ~ : ghost
USAGE: ghost add <hostname> [<ip=127.0.1.1>]
       ghost modify <hostname> <ip>
       ghost delete <hostname>
       ghost list
       ghost empty

Okay, let’s see if there is anything already listed.

   ~ : ghost list
  Listing 0 host(s):

Nope. Let’s test this out. First, we’ll try to ping a domain name that we hope doesn’t exist.

   ~ : ping bigbrown.cow
  ping: cannot resolve bigbrown.cow: Unknown host  

Alright, now we’ll add bigbrown.cow with ghost.

   ~ : ghost add bigbrown.cow
  Password:
    [Adding] bigbrown.cow -> 127.0.0.1

As you can see, it required root credentials to do this as it’s system-wide. Let’s now see if we can talk to bigbrown.cow.

   ~ : ping bigbrown.cow     
  PING bigbrown.cow (127.0.0.1): 56 data bytes
  64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.047 ms
  64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.035 ms
  ^C
  --- bigbrown.cow ping statistics ---
  2 packets transmitted, 2 packets received, 0% packet loss
  round-trip min/avg/max/stddev = 0.035/0.041/0.047/0.006 ms

Excellent! If we run ghost list again, we should see this record.

~ : ghost list
Listing 1 host(s):
  bigbrown.cow -> 127.0.0.1

We can modify the record to a non-localhost IP as well with ghost modify.

   ~ : ghost modify bigbrown.cow 192.168.10.104
    [Modifying] bigbrown.cow -> 192.168.10.104
   ~ : ghost list
  Listing 1 host(s):
    bigbrown.cow -> 192.168.10.104  

I’ll let you play with it yourself as there isn’t much to it. This is a great little addition to my development environment. Thanks to Nathan for pointing it out and to Bodaniel Jeanes for creating this useful gem.

After releasing the new RubyURL API, I decided that it was time to look around at libraries to interact with it. I came across a new Ruby gem from John Nunemaker named, HTTParty, which aims to make it easy to talk to XML and JSON-based web services. Be sure to read John’s announcement of HTTParty.

So, I decided it might be fun to introduce more people to the gem by showing you all how to use it to talk to the new RubyURL API.

Install HTTParty

Before we get started, you’ll need to install the HTTParty gem with the following command:

   ~ : sudo gem install httparty
  Password:
  When you HTTParty, you must party hard!
  Successfully installed httparty-0.1.6
  1 gem installed
  Installing ri documentation for httparty-0.1.6...
  Installing RDoc documentation for httparty-0.1.6...

Great! Now that we’re ready to party hard, let’s build something.

Talking to the RubyURL API

The RubyURL API currently supports both XML and JSON, which are each supported by HTTParty. The great thing about HTTParty is that all you need to do is include it in a class and you’re able to quickly talk to remote services.

In this following example, we’re going to create a new class called Rubyurl.

class Rubyurl
end

What we’ll want to do now is include the HTTParty library. (note: you’ll need to require both rubygems and httparty gems and I’ll skip those lines in following code samples)

class Rubyurl
  include HTTParty
end

The HTTParty provides a few class methods, which we can use to configure our library. We’ll go ahead and specify the base_uri, which we’ll set to rubyurl.com.

class Rubyurl
  include HTTParty
  base_uri 'rubyurl.com'
end

Now that our class is setup to talk to the Rubyurl.com site, we’ll want to add a new method which we can use to communicate with the RubyURL API. We’ll call this shorten as we’re using RubyURL to shorten long URLs… right?

class Rubyurl
  include HTTParty
  base_uri 'localhost:3000'

  def self.shorten( website_url )
  end
end

Our new shorten method will expect us to provide it with a website url, which we’ll want RubyURL to return a shortened URL for. The PATH for the API that we’ll want to talk to is: /api/links, which we’re expected to pass XML or JSON to.

Here are two examples of using the RubyURL API with HTTParty.

RubyURL via JSON w/HTTParty

We’re going to use the post method that is provided with HTTParty to send a request to /api/links.json. As you can see, we’re providing the original website url to the web service.

class Rubyurl
  include HTTParty
  base_uri 'rubyurl.com'

  def self.shorten( website_url )
    post( '/api/links.json', :query => { :link => { :website_url => website_url } } )
  end
end

When ran, it’ll produce the following:

  >> Rubyurl.shorten( 'http://github.com/jnunemaker/httparty/tree/master/lib/httparty.rb' ).inspect
  => {"link"=>{"permalink"=>"http://rubyurl.com/uJVu", "website_url"=>"http://github.com/jnunemaker/httparty/tree/master/lib/httparty.rb"}}

Pretty simple, eh?

RubyURL via XML w/HTTParty

The great thing about HTTParty is that you can use XML without changing much.

class Rubyurl
  include HTTParty
  base_uri 'rubyurl.com'

  def self.shorten( website_url )
    post( '/api/links.xml', :query => { :link => { :website_url => website_url } } )
  end
end

Produces the following

<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<link>
  <website_url>http://github.com/jnunemaker/httparty/tree/master/lib/httparty.rb</website_url>
  <permalink>http://rubyurl.com/uJVu</permalink>
</link>

Closing thoughts

So… there you have it. HTTParty makes it extremely easy to interact with various web services that work over HTTP. I’d encourage you all to take a few minutes to experiment with it and see what crazy ideas that come to mind during the process. :-)

After noticing a few patch requests on Rubyforge.. I decided that I’d put the ShortURL gem up on GitHub as I spend quite a bit of my time there these days. :-)

• http://github.com/robbyrussell/shorturl/tree

I’ve also thrown up a few lines of code so that you can get the gist of the gem. ;-)

Earlier today, Vincent Foley was kind enough to hand over maitenance of the the ShortURL project on RubyForge to me. He first released it back in 2005, which I blogged about as RubyURL was the first shortening service that it supported (and is the default). Unfortunately, the release of RubyURL 2.0 broke backwards compatibility and Vincent wasn’t maintaining it anymore. So, earlier, I decided to patch this and got a new version released that now works with the current RubyURL site.

While working on the code, I decided to extend the compatible services to include moourl and urlTea.

These updates are available in ShortURL version 0.8.4.

Install the ShortURL gem

Installation is a snap… (like 99.7% of rubygems…)

  ~ > sudo gem install shorturl                                                                                                                                                                                                           Password:

  Successfully installed shorturl-0.8.4
  1 gem installed
  Installing ri documentation for shorturl-0.8.4...
  Installing RDoc documentation for shorturl-0.8.4.  

Using ShortURL

The ShortURL gem provides the ShortURL library, which you can use from any Ruby application.

Using the ShortURL library

  ~ > irb                                                                                                                                                                                                                           
  irb(main):001:0> require 'rubygems'
  => true
  irb(main):002:0> require 'shorturl'
  => true
  irb(main):003:0> ShortURL.shorten( 'http://www.istwitterdown.com' )
  => "http://rubyurl.com/P9w" 

As you can see…it’s really straight forward.

Let’s try it with a few other services.

irb(main):004:0> ShortURL.shorten( 'http://www.istwitterdown.com', :moourl )
=> "http://moourl.com/fvoky" 
irb(main):005:0> ShortURL.shorten( 'http://www.istwitterdown.com', :tinyurl )
=> "http://tinyurl.com/2t3qmh" 

Using the shorturl command-line tool

Many people don’t know that ShortURL provides a command-line tool, which you can use after installing the gem.

  ~ > shorturl http://istwitterdown.com                                                                                                                                                                                               
  http://rubyurl.com/Lwk

If you’d like to see more services provided than the ones listed here, please submit feature requests and/or patches on the rubyforge project.

• http://rubyforge.org/projects/shorturl/

ShortURL Documentation

To see the latest documentation for the project, please visit:

• http://rubyforge.org/projects/shorturl/

My favorite part about this? My rbot plugin for RubyURL works again!

Uploaded with plasq’s Skitch!

Happy URL-shortening!

Hey! You’re a cheater!

Well, if you’re not… I’m hoping to make one out of you.

“A thing worth having is a thing worth cheating for.”—W. C. Fields

I’m a fan of the PDF cheat sheets as I like the consolidated content contained in them. However, I don’t like having to read PDFs any more than I have to. Printing them isn’t always ideal either as I really don’t like to carry around extra paper in my laptop bag. So, what are we to do?

Well, you can cheat the system! ...and I’m going to show you how!

Cheat is this really nice command-line tool that outputs a plain text cheat sheet whenever and wherever you want.

Install the Cheat

Like all the happy and good Rubygems, this is quite simple…

$ sudo gem install cheat

Done! Okay… let’s try to do some cheating. Don’t worry, your friends and family will forgive you.

Becoming a Cheat(er)

To view a cheat sheet, just run the cheat command from your favorite terminal window.

$ cheat _cheat name_

So, for example… to see the cheat sheet for RSpec, run cheat rspec.

    $ cheat rspec
    rspec:
      INSTALL
      =======
      $ sudo gem install rspec

      $ ./script/plugin install
      svn://rubyforge.org/var/svn/rspec/tags/REL_X_Y_Z/vendor/rspec_on_rails/vendor/p
      ugins/rspec
      Where X_Y_Z is the version number.

      $ ./script/generate rspec
            create  spec
            create  spec/spec_helper.rb
            create  spec/test2spec.erb
            create  test/test2spec_help.rb
            create  script/rails_spec
            create  script/rails_spec_runner

      HOW TO USE
      ==========
      ./script/generate rspec_model User

####################################################
# truncated to save precious bandwidth
####################################################

Because this is all printing out in your shell, you can take advantage of your favorite command line tools.

Piping to grep

$ cheat rspec | grep 'equal' 
      @user.errors.on(:username).should_equal "is required" 
  target.should_equal <value>
  target.should_not_equal <value>

Piping to TextMate

$ cheat rspec | mate

Find more Cheats

Head over to this list of cheats to see what is currently available.

Thanks to the Err team for putting this together!