Ruby on Rails does a great job of parsing arrays in form data and populating a params hash, for quick and easy access in your controllers. For instance Gives you params[:item] # => ["item 1", "item 2"] Flask doesn't do this work f...

Here is a little ruby snippet that will download all pictures from a webpage. Rather than using XPath, we are going to first reduce the source code to capture everything inside of quotes. Some websites use JSON w/in a script tag to lazy load images an...

To get a Gravatar you need to hash an email address with the MD5 algorithm. MD5 is a part of the Ruby standard library. Rails loads it by default, but otherwise you will have to require it yourself. This is a simple implementation. Gravatar su...

r = /https?:\/\/[\S]+/i you_string.gsub(r, '') Here's the rubular regex to play around with yourself http://rubular.com/r/SRKkYrW4IJ

If you get this error message ActiveRecord::ConnectionTimeoutError could not obtain a database connection within 5.000 seconds (waited 5.001 seconds) Try closing the connection after each request using "after" in Sintara. # app.rb after { A...

Session based flash messages are fairly common in web apps. They work well when you have a temporary status to report back to the user, such as successfully saving a form. If you use Rails it comes with the Framework. If you are using Sinatra there ar...

Rails will infer the controller you want to test from the class name of the test case. For example... class PeopleControllerTest < ActionController::TestCase end will test the app/controllers/people_controller.rb. To change this is trivial. Us...

In your project's root directory add a .ruby-version file and add the ruby version to the file ruby-2.0.0-p247 Next source RVM in the .powrc file, also in your project's root directory. source "$rvm_path/scripts/rvm" rvm use `cat .ruby-versio...

Here is the snippet f path/to/directory 'search string' | open_in_mate This snippet (technically 2 snippets) will recursively scan the contents of files in a directory and then open all the files it finds in Textmate. It's useful on large projec...

You need to read from STDIN rather than parse command line arguments. while $stdin.gets puts $_ end

# time_ago_in_words(Time.now, 1.day.ago) # => 1 day # time_ago_in_words(Time.now, 1.hour.ago) # => 1 hour def time_ago_in_words(t1, t2) s = t1.to_i - t2.to_i # distance between t1 and t2 in seconds resolution = if s > 29030400 # seco...

Foreman is a process management gem for ruby applications. It is used in combination with a Procfile for configuration instructions. A typical Procfile looks something like this [name] : [script to execute] Example Rack application Procfile ...

Sinatra doesn't have a method for rendering partials. It defers to the template language of your choice. For instance, if you're using ERB, it's as simple as erb :'path/to/partial' Rails has a nice convention of using an underscore to mark file...

This actually has more to do with Rails and/or Sinatra than it does with Heroku. You have to enable IFrame support in your headers explicitly. With Rails you can add this to your config/application.rb file config.action_dispatch.default_headers = ...

This regular expression matches non alphanumeric characters in a string. r = /[^a-z0-9]{1,}/i You can use it to create URL friendly slugs. slug = "hello world!".gsub(/[^a-z0-9]{1,}/i, '-').downcase # => hello-world In combination wit...

If you run into this error message try switching to an earlier version of ExecJs. JSON::GeneratorError: only generation of JSON objects or arrays allowed # Gemfile gem 'execjs', '~> 1.4' gem 'coffee-script' gem 'sass' ...

This snippet will make a request to this page and extract the title from the title tag. require 'open-uri' html = open('http://www.seanbehan.com/how-to-extract-the-title-from-an-html-page-with-ruby').read title = html.match(/(.*)/) { $1 } pu...

# Edit Rakefile in project root # # Add a new rake test task... E.g., rake test:lib, below everything else in that file... # Alternatively, add a task in lib/tasks/ directory and plop in the same code namespace :test do desc "Test lib source" ...

Here is a gist that demonstrates how easy it is to transform text using #gsub and a block with Ruby. "Scs Epc Score".gsub (/scs|epc/i) { |i| i.upcase } # => SCS EPC Score For more helpful string extensions in Ruby check out our Ruby Gem on GitHub...

If you are testing using Test:Unit (rather than RSpec) and you're using Ruby 1.9.* colorized output of your tests using Autotest will not be immediately available. Since, 1.9 comes with mini test the test/unit/ui/console/testrunner.rb script is not loaded...

require 'yaml' # Nested YAML structure from something-nested.yml # # nested: # key: value # key_two: value_two # Procedural Approach to building a single Hash from nested YAML data structure. @yaml = YAML.load_file("something-nested...

Regular Expression that Matches Email Addresses: /\b[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}\b/

I had an old version of rvm installed and wanted to upgrade. So old in fact that the resource for upgrading no longer existed. rvm update just returned a 301, redirect. Luckily, the following worked # checks out from repo rvm update --head # will re...

I love the Rails reload! function when in the console. I need it in Irb. To get it back this is what I did. If you don't already have an .irbrc file in your home directory, just create it. vim ~/.irbrc or textmate if you prefer mate ~/.irbrc Add this...

I just wrote and released my first Ruby Gem, Hashed Attributes https://rubygems.org/gems/hashed_attributes. It is a very simple ActiveRecord extension for saving variables through a serialized hash. The Gem will let you declare getter and setter methods t...

I assumed that rand would take a range as an argument. Something like rand(10..20), generating a random number between 10 and 20. Seems like you'd do this fairly often when working with random numbers and therefore, included. However, it doesn't work. But...

Short and sweet. Here all the commands I run in this order to set up a brand new box. It usually takes about 10 - 15 minutes on a 256 MB RAM instance. Compiling Ruby Enterprise Edition, which is super easy, will take the most amount of time. It will seem ...

After installing Ruby Enterprise Edition, REE, and Passenger on Ubuntu you may see this error message when you run script/console for the first time ./script/console production # => Loading production environment (Rails 2.3.5) Rails requires RubyGems >=...

What is RVM and why should you use it? RVM is a Ruby interpreter, version management tool. In short, it enables you to switch between different versions and releases of Ruby (for instance, version 1.8.6, 1.8.7, jruby 1.9.2, ruby enterprise edition) on the...

Forms can easily get cluttered when you're dealing with a lot of form fields... er, ERB tags. I've written about extending Rails form builders, which certainly goes along way to shrinking your views where forms are used. The plugin Formtastic is even bett...

Here is a simple rake task which will instantiate all of your Active Record models, provided that they are located in the RAILS_ROOT/app/models directory. Interestingly, all plugin models are instantiated by default when you run the task, for instance, if...

Working with Ruby and in particular Rails, it's easy to take the beauty inherent in the language for granted. I mean look at this code. If you read it aloud to yourself, it reads like an english sentence that any non programmer can understand. Forum.cate...

If you follow the instructions on how to install the Rails Redmine PM Software (available here) and are using Apache with Passenger (REE), you need to delete the .htaccess file that is kept in RAILS_ROOT/public directory. Otherwise you'll see a 404 page n...

Active Record find methods for selecting range from http://charlesmaxwood.com/notes-from-reading-activerecordbase/ Student.find(:all, :conditions => { :grade => 9..12 }) return a range Student.find(:all, :conditions => { :grade => [9,11,12] }) will retu...

%e # rather than %d Time.now.strftime("%e")

Here is how to install a Rails application out of a subdirectory (rather than as a subdomain) with the Apache web server(Apache2). In this example I'm going to use my own blog which is a Wordpress installation and serve a Rails application from the subdir...

What is Rack? Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and sof...

These aren't all of them, but I think they are some of the most useful. # making a directory in another directory that doesn't yet exist... FileUtils.mkdir_p '/path/to/your/directory/that/doesnt/exist/yet' # recursively remove a directory and the conten...

Great little gem that let's you quickly and easily send out mail from your ruby scripts. gem install pony require 'rubygems' require 'pony' Pony.mail :from=>"me@example.com", :to=>"you@example.com", :subject=>"hello", :body=>"world"

Installing monk like this will fail gem install monk You'll need to install the wycats-thor gem first with this command gem install wycats-thor -s http://gems.github.com

Check it out http://sinatra.seanbehan.com/ This assumes Apache2 and the Phusion Passenger module have already been installed. If not you can get up to speed w/ this resource http://seanbehan.com/ruby-on-rails/new-ubuntu-slice-apache-mysql-php-ruby-on-rail...

If you want to get version information about a gem the easiest way to do it is with this command gem list For example gem list activemerchant will output the activemerchant versions I have installed. You can pass only part of the name like gem list ...

[youtube]http://www.youtube.com/watch?v=sb2xzeWf-PM[/youtube]

I've got some pages that are cached using their permalinks on the filesystem, such as http://example.com/about-us.html which will need to map to RAILS_ROOT/public/about-us.html ... The issue I have is that I use a namespace for the admin area and the cont...

I'm working on a project that requires users/designers be allowed to edit the layout of their site. I'm using Liquid, Ruby templating system developed by the folks at shopify.com. Doing a little searching I found this great post http://giantrobots.though...

If you use a consistent date format often in your Rails applciation, it is worth it to add the format to your application environment. You can do this by adding  it to the bottom of the config/environment.rb file. Time::DATE_FORMATS[:my_custom_format] ...