By Charles Max Wood
Your Playbook for Ruby on Rails
CoffeeScript is a language written by Jeremy Ashkenas that compiles to Javascript. Its syntax is much more friendly than native JavaScript. Especially if you're used to languages like Ruby or Python. As or Rails 3.1, CoffeeScript is available by default and...
A generator is a way of creating code from the command line. Rails has several of these built in, including generators for models, controllers, tests, helpers, scaffold (models, views, and controllers that support Rails' RESTful routing), and much more. Generators are...
NoSQL is a terrible term for a collection of widely varied databases. You have key-value stores like Redis, Tokyo Cabinet, Memcached, etc. You also have document databases like couchDB and mongoDB. Finally you have column based systems like Cassandra. And...
I've been using Backbone.js for a few weeks and really like the way it helps you manage your data on the client side. It's also a terrific way to keep your UI in sync when your data changes through Javascript...
One of the most handy websites out there for people trying to find specific API's in Ruby is ruby-doc.org. From the main page, you can search or select your Ruby version. From the core page, you can narrow down the class or...
I've been using VIM for a while to do my development. It's a terrific text editor that has been around for quite some time. Here's the rundown of what I've got set up. MacVim: http://code.google.com/p/macvim/ Janus: https://github.com/carlhuda/janus I've also found a few resources to help...
A counter cache is a handy way to speed up queries where you only need the number of an associated model rather than the entire collection. In your code, you might see something like this: @post.comments.count When you run this code, you...
Eager loading is a terrific way of speeding up your response times. Let's consider a piece of code that pulls a list of associated objects from the database. For example, a view that displays the posts written by a given...
Assets in Rails before version 3.1 were kept in the /public folder. In Rails 3.1 they've been moved to /app/assets and function in a slightly different way. Here are some of the highlights: Javascript assets written in Coffeescript will now be compiled...
About a month ago, I talked about ActiveRecord Callbacks. Observers are a way of moving callbacks out of the Model. Usually this is done to adhere to the Single Responsibility principle. So, for example, programmers will move sending an email...
I’ve been working on an ORM for Cassandra. One of the things I’ve been using to build the ORM is ActiveModel. ActiveModel gives you modules you can add to your class that makes it behave like an ActiveRecord Model. Here are...
Building web forms in Rails was something that confused me when I was new to the framework. This is probably due to the fact that there are some methods that are a lot alike and there are a couple of...
Rails has the concept of Polymorphic associations, which are associations that can be of different data types. For example, let’s say we have a Comment model. A comment in your app can be on a post or a page. Rather...
ActiveRecord models are based upon tables in relational databases. This, of course, means that they can be relational. Models can associate in three main ways: one to many, one to one, and many to many. One to many is usually achieved...
In your Rails controllers you have filters you can place on incoming requests, outgoing responses, or wrap around your actions. Before filters are run on requests before the request gets to the controller’s action. It can return a response itself and...
You can get a full list of the ActiveRecord callbacks here. Callbacks are a handy way of insuring specific behaviors on your models as well as managing the events that follow the callbacks. For example, a before_destroy callback can be called to...
According to The Pragmatic Programmer by Andy Hunt and Dave Thomas, "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system." Last week I talked about extending your Ruby on Rails application. This is because in many...
I’m going to be talking about the DRY principle next week. However, before I jump into that, I need to discuss how to extend Ruby on Rails so you know where you can put functionality to keep your application DRY. There...
Rails is made up of several components that all have specific jobs in making your Rails application work. Here’s a quick list of what they are and what they do. ActionMailer - The basis for mailers. This is the library...
We talked quite a bit today about debugging tools in the Ruby Rogues podcast. I recorded this before that episode. Here's a brief introduction on how to use debuggers to find problems in your Rails code. The basic idea is that...
The idea behind convention over configuration is that rather than having several or one large configuration file to set up the framework for you to use, Rails uses conventions to determine how things should work without configuration. In many cases...
Ruby on Rails routing can be a little confusing. Here are some of the high points. The root path is specified by the 'root' method. It matches the '/' path and behaves like 'match'. The 'match' method will match the requested path...
Rails Engines are a terrific way of mounting on Ruby on Rails application into another. A Rails Engine is basically a Rails application with an Engine class installed. The main application—the application your engine is mounted into—uses the generators, rake tasks,...
Ruby has a package manager for its libraries or gems. It should be a concept familiar with other package managers like apt, yum, or yast. Gems are libraries for Ruby. Many gems are built to extend Ruby on Rails and...
Rails Migrations are generally pretty straightforward, but there are a few things that people do that wind up giving them headaches later on. First, don't change migrations once they've been committed or deployed. This causes problems because ActiveRecord tracks migrations...
Libraries for Authorization controls in Ruby on Rails are not nearly is prolific as they are with Authorization. The one I typically use is Cancan. The thing I like about Cancan is that it provides fairly granular model level controls. You...
In a lot of web applications, you need to control who can access your data. Authentication is the key to this type of security. Ruby on Rails has some plugins and gems that make authentication pretty easy. Here are a...
There are a lot of tools for testing Rails. Here are links to several of the ones mentioned in this podcast. Test Unit RSpec Cucumber Mocha Flexmock Factory Girl You can find my interview with David Heinemeier Hansson here, and my response to his comments on Twitter...
You can get the video version of this podcast here. I've also updated the audio files for episodes 2 & 3 so you can hear them now. Sorry for the trouble. Ruby on Rails provides some excellent ways to validate the data...
Single Table Inheritance is a slightly advanced topic in Ruby on Rails. It stems from class inheritance, which is a core Object Oriented Programming principle. In Ruby, if you inherit one class from another, you use the '<' operator. Here's an...
This is a brief explanation of how Rails implements the MVC design pattern to create such an awesome framework for building websites. In a nutshell, when a request comes to a Ruby on Rails website, it's handed the dispatcher. The dispatcher...
Some people wonder if they need to know Ruby to program Ruby on Rails. My answer is "kind of." Ultimately, when you program in Ruby on Rails, you program in Ruby. That being said, you don't need to know the ins...
