Perplexed Labs » Ruby on Rails

google-define and last-fm plugins released

Eric — Thu, 06 May 2010 16:44:58 +0000

Over the last few days I released my first open-source plugins on GitHub.

google-define - Extracted from a side project I worked on, it's basically a wrapper class for parsing definitions from Google (define:perplexed).
last-fm - This plugin was inspired by a previous gist, which itself was taken from an app I wrote to aggregate the last week's movies, books, and music to send to Posterous (example here). It's another wrapper class for easily parsing last.fm XML feeds.

I hope someone finds these useful. Any and all feedback is appreciated.

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FormStack API Call Over SSL With Ruby

Eric — Wed, 28 Apr 2010 17:45:44 +0000

I recently had to use the FormStack API in the context of a Rails app. You need to make these calls over SSL, and API returns either XML or JSON. I chose JSON because it's much easier to work with in my opinion and I hate XML.

Below is a simple example. Check out the FormStack API documentation for all the other API calls.

8 Books To Get A Developer For The Holidays

Matt — Mon, 30 Nov 2009 13:30:06 +0000

Send this to your significant other/parent/relative/friend so, instead of that sweater, you get one of these nuggets of awesome this Christmas.

The Pragmatic Programmer: From Journeyman to Master

Write better, cleaner, more maintainable code. Learn how to manage your projects and focus on shipping your product. With insight that covers the gamut of software development from low level to management
this one is a must have for anyone involved in this industry.

The Passionate Programmer: Creating a Remarkable Career in Software Development

Highly recommended! Read my full review.

Code Complete: A Practical Handbook of Software Construction

Another classic "software construction" book. Sharpen your saw with timeless information that can be applied to any project in any language. Less bugs, more productivity, more programmer happiness.

Coders at Work

This one is different. Written as a set of interview transcripts with 15 legendary industry giants, this book is a fantastic insight into how some of the great minds think. It's inspiring to hear it from the source, must have!

Programming Clojure

A developer should learn at least one new language a year. This year that language should be Clojure. Clojure is a dynamic, general purpose, language targeting the Java virtual machine and designed for multi-threaded use. It's growing popularity, ability to leverage the Java standard library, and its multi-threaded nature make this a must have.

The Mythical Man-Month: Essays on Software Engineering

Another classic. Primarily discusses project management from the perspective of Fred Brooks and his experiences at IBM. Brooks' Law states that "adding manpower to a late software project makes it later".

Don't Make Me Think: A Common Sense Approach to Web Usability

Web developers should always keep in mind the user of the product their creating. Usability becomes increasingly important as applications move to the web. The design and usability of your app can make or break its success. This classic is a must read.

Design Patterns: Elements of Reusable Object-Oriented Software

This classic known most commonly as the "gang of four" book is the definitive reference on design patterns. Covering all of the most common cases and time and time again serving as an invaluable source of information.

Twitter and SD News

Eric — Fri, 31 Jul 2009 17:24:28 +0000

Motivation: SD News is a "social news site" (basically a Hacker News clone), written in Rails, that I work on as part of my efforts with a Christian publishing company I run with some friends. As part of the administrative backend, I wanted to be able to send posts to our Twitter profile. The site is still young, and the community still growing, so I wanted the admins to have complete control over what gets sent to Twitter. I had thought of automating this process based on which items have the most votes in a given time period, but trust is easy to lose and all it would take is 1 or 2 irrelevant, or irreverent. posts to lose that trust.

Methodology: I would first need a good Twitter gem for Ruby, and I'd need to decide which URL shortening service I'd use. Ruby Twitter seemed to be the simplest gem for Twitter. For the URL shortening I chose bit.ly, because the bitly gem seemed like the easiest, and the documentation was good. My plan of attack was:

Grab one item from the queue, that has not been Twittered
Shorten the URL via bitly
Send the item's title and shortened URL to Twitter
Save the shortened URL in the database so I could retrieve stats later

The script that did this would be run every hour.

Implementation: The two gems made this an almost trivial implementation.

require 'twitter'
require 'bitly'

@item = Item.find(:first, :conditions => "send_to_twitter = 1 and twitterd = 0", :order => "posted_on desc")

if !@item.nil?
   b = Bitly.new(username, password)
   @url = b.shorten("http://news.sensusdivinitatis.com/item/#{@item.id}").short_url

   httpauth = Twitter::HTTPAuth.new(username, password)
   base = Twitter::Base.new(httpauth)
   base.update("#{@item.title[0...110]} - #{@url}") #shorten the title if it's too long

   Item.update(@item.id, :twitterd => 1, :bitly_url => @url) #save the bit.ly url
end

That's pretty much it. Incidentally, the bitly gem makes it very easy to grab the stats for any URL. For instance, if you wanted to see how many clicks a given URL has received:

require 'twitter'
require 'bitly'

@item = Item.find(id)
b = Bitly.new(username, password)
@clicks = b.stats(i.bitly_url).stats["clicks"]

Done.

Be Language Agnostic – Solve the Problem!

Matt — Mon, 01 Jun 2009 14:15:28 +0000

I like Python. I like Ruby. I like C, C++, and Objective-C. I like Java. I also (actually) like PHP. I like programming - get it? Use whatever gets the job done and done well. Use whatever achieves the performance and scalability you require for a given task. Use what makes sense given a specific problem's domain. ~~Use whatever aligns itself with the way your mind works~~. Don't be a one trick pony (that isn't a Django reference). Learn multiple languages, their strengths, and their weaknesses. Understand when a language's strengths will allow you to solve a problem faster, easier, better. Don't force a square peg through a round hole.

Watch this video. It's excellent food for thought and drives home the importance, as a programmer, of learning new, different, languages to expand your ability to solve problems in a variety of ways. The video mentions the Sapir–Whorf hypothesis which suggests that a particular language influences how a person understands and interacts with the world. This makes a lot of sense.

A programmer who thinks only in terms of a single language will attempt to solve every problem with that language. You need more than one tool on your belt because not every problem is a nail.

37Signals and PHP?

Matt — Tue, 21 Apr 2009 16:39:31 +0000

What exactly are they using it for? Front-end?

Installing Ruby Enterprise Edition with Phusion Passenger

Eric — Tue, 13 Jan 2009 15:00:18 +0000

I've been using Phusion Passenger for a few months now and I'm really pleased with it. The performace vs. Mongrel is better, but what makes it so useful is the ease of deployment. Being able to setup a vhost in Apache just like you would for a PHP application was very appealing to me. Having previously worked with the Apache/Rails/Mongrel/mod_proxy stack in an "enterprise" environment for over a year, I have experienced pretty much every nightmare deployment scenario possible. I recently decided to install Phusion's Ruby Enterprise Edition, which promises up to a 33% savings in memory usage.

Before you do anything, and to save you trouble down the road, I recommend generating a list of all the gems currently installed. You'll need this later because you'll have to reinstall all of them in Ruby Enterprise Edition.

$ gem list

*** LOCAL GEMS ***

actionmailer (2.0.2)
actionpack (2.0.2)
activerecord (2.0.2)
activeresource (2.0.2)
activesupport (2.0.2)
acts_as_taggable (2.0.2)
amazon-ecs (0.5.3)
cgi_multipart_eof_fix (2.5.0)
daemons (1.0.10)
fastthread (1.0.1)
gem_plugin (0.2.3)
hpricot (0.6)
mongrel (1.1.4)
mysql (2.7)
passenger (1.0.1)
rails (2.0.2)
rake (0.8.1)
rspec (1.1.3)
will_paginate (2.2.2)
xml-simple (1.0.11)

Copy your list and save it somewhere. Next, we download and extract the current version of Ruby Enterprise Edition. The latest version number can be found at the download page.

$ wget http://rubyforge.org/frs/download.php/48623/ruby-enterprise-1.8.6-20081215.tar.gz
$ tar xzvf ruby-enterprise-1.8.6-20081215.tar.gz

And run the installer

$ ./ruby-enterprise-1.8.6-20081215/installer

As the installation proceeds, you'll be prompted for an installation directory. I went with the default. When the installation is over, you should see a message like this:

Ruby Enterprise Edition is successfully installed!
If want to use Phusion Passenger (http://www.modrails.com) in combination
with Ruby Enterprise Edition, then you must reinstall Phusion Passenger against
Ruby Enterprise Edition, as follows:

/opt/ruby-enterprise-1.8.6-20081215/bin/passenger-install-apache2-module

Make sure you don't forget to paste the Apache configuration directives that
the installer gives you.

If you ever want to uninstall Ruby Enterprise Edition, simply remove this
directory:

/opt/ruby-enterprise-1.8.6-20081215

If you have any questions, feel free to visit our website:

http://www.rubyenterpriseedition.com

Enjoy Ruby Enterprise Edition, a product of Phusion (www.phusion.nl)

I do want to use Ruby Enterprise Edition and Apache, so I immediately installed the Apache module.

$ /opt/ruby-enterprise-1.8.6-20081215/bin/passenger-install-apache2-module

You need to pay attention to the Apache directives that this installation generates, since you'll have to put them into your httpd.conf:

The Apache 2 module was successfully installed.

Please edit your Apache configuration file, and add these lines:

LoadModule passenger_module /opt/ruby-enterprise-1.8.6-20081215/lib/ruby/gems/1.8/gems/passenger-2.0.6/ext/apache2/mod_passenger.so
PassengerRoot /opt/ruby-enterprise-1.8.6-20081215/lib/ruby/gems/1.8/gems/passenger-2.0.6
PassengerRuby /opt/ruby-enterprise-1.8.6-20081215/bin/ruby

What that message doesn't explain is that, if you previously installed Passenger without Ruby Enterprise Edition, you need to comment out any old directives attached to that previous setup. I made that mistake the first time around.

Next you have to reinstall all the gems that you were using with old Ruby, including Rails:

/opt/ruby-enterprise-1.8.6-20081215/bin/ruby /opt/ruby-enterprise-1.8.6-20081215/bin/gem install rails --version 2.0.2

Just to prove my point, if you listed all of Enterprise Ruby's gems at this point, the list would look something like this:

$ /opt/ruby-enterprise-1.8.6-20081215/bin/ruby /opt/ruby-enterprise-1.8.6-20081215/bin/gem list

*** LOCAL GEMS ***

actionmailer (2.2.2, 2.0.2)
actionpack (2.2.2, 2.0.2)
activerecord (2.2.2, 2.0.2)
activeresource (2.2.2, 2.0.2)
activesupport (2.2.2, 2.0.2)
fastthread (1.0.1)
mysql (2.7)
passenger (2.0.6)
rack (0.9.1)
rails (2.2.2, 2.0.2)
rake (0.8.3)

None of my old gems are installed. Once Rails is installed, you need to reinstall your old gems:

$ /opt/ruby-enterprise-1.8.6-20081215/bin/ruby /opt/ruby-enterprise-1.8.6-20081215/bin/gem install will_paginate
$ /opt/ruby-enterprise-1.8.6-20081215/bin/ruby /opt/ruby-enterprise-1.8.6-20081215/bin/gem install xml-simple
$ /opt/ruby-enterprise-1.8.6-20081215/bin/ruby /opt/ruby-enterprise-1.8.6-20081215/bin/gem install hpricot
$ /opt/ruby-enterprise-1.8.6-20081215/bin/ruby /opt/ruby-enterprise-1.8.6-20081215/bin/gem install rmagick

And on and on. If you haven't used Passenger before, check out the Deployment Guide. If you have used Passenger and your Rails apps are already set up in Apache to take advantage of it's deployment procedures, simply restart Apache.