Here’s a list of things I like about Ruby on Rails. Almost every single one of these are available in at least one Python framework in some form, but the best thing about Rails is how polished the pieces are and how well they all fit together. The whole is truly greater than the sum of its parts.
Rails has a fantastic out-of-box experience. Simply execute rails new and you’re off to the races with a directory full of goodies that every real web app needs: dependency management, build system, multi-environment configuration, development storage, logging, custom error pages, robots.txt file and more. See section 3.2 of the getting started guide for a complete list. Hell, they even fill out a .gitignore file for you! A place for everything and everything in its place.
Dependency Management: RubyGems
In the Python world, easy_install and its ilk are all kinds of broken. You can’t even uninstall a package! Luckily, there is Pip and Virtualenv, but assuming Pip supports all your packages, you’ve still got to make sense of dependency freezing and manually setup a virtual environment. With Rails, that all just works: rails server runs in a virtualized environment and loads gems as defined by your Gemfile; rails console for a repl. No need to muck with sys.path! Any seasoned developed has spent many an hour in dependency hell, but it is still hard to justify the infrastructure investment before writing a line of HTML. Bonus points for the “vendor” directory, in case you need to patch a third party package (or Rails itself) and want to keep it under version control.
Build System: Rake
gnu.org/software/make/manual/make.html”>Makefiles. A lot of people really hate them, but they are just so damn useful. Frequently, you need to transform some set of files into some other set of files, but only when they change. Makefiles help you do that reliably. They accomplish their feat explicitly by not being a programming language, but a dependency and build rule declaration language. I’ve seen a lot of attempts at build systems that aim to be idiomatic with respect to their host languages. Java has Ant and Maven. Python has Scons and others. Scala has Simple Build Tool. None of them are as good as plain old Makefiles. Then, I discovered Rake. Rakefiles rock. They are 90% Makefiles, and 90% Ruby. Rake expertly uses the features of Ruby to craft an API/DSL that looks a lot like Make declarations without compromising on general purpose programmability.
Markup and Style Sheets: Haml and Sass
Haml and Sass are so amazing, they ought to be illegal. Just click those links and check out the HTML and CSS comparisons. It is no contest. I never want to write HTML or CSS ever again. As far as I’m concerned, HTML and CSS are object code: to be generated by a compiler. Whenever I have to look at the generated code, it feels like I am reading assembly. Simply add gem ‘haml’ to your Gemfile, then start writing .html.haml files instead of .html.erb and .sass files instead of .css. Use html2haml and sass-convert to upgrade your crusty old markup and style sheets instantly.
Object Relational Mapper: ActiveRecord
I’ve discussed my preference for database schema reflection at great length, so I won’t reiterate here. I will, however, say that ActiveRecord makes simple things simple and complex things possible while embodying successful best practices in its various subsystems, like migrations. It doesn’t try to be everything to everyone, unlike SqlAlchemy. And it seems to be nicely onion layered for pealing back when necessary. For example, ActiveModel validations can be used on plain old Ruby objects. Which brings me to…
Form Handling: FormBuilder, params and mass assignment
I don’t need to learn and manage three different data marshaling techniques to map a database record to a web form. In fact, I don’t need to manage any. Schema reflection spares me in the model layer, FormBuilder/FormHelpers in the views, and the hash & array structured params in the controllers layer. Almost every user interaction boils down to interpreting a form’s worth of JSON-like data structures as an API call, implemented via a (secured) mass assignment to virtual attributes.
Templating: Layouts, Partials, and Helpers
When I’m getting my Haml on, I frequently want to run some non-trivial code. Feel free to shout about your separation of concerns religion, but I’ve got real things to worry about. Furthermore, we as engineers should be writing our production views/templates, not some hypothetical designer who is technical enough to write loops and branching statements, but not to be trusted with a function definition. Views are composed of markup and presentation declarations in the templates, presentation logic goes in helpers (which conveniently share scope with templates and controllers), and are neatly organized into partials. Simple, but effective.
URL Design: Routes
Rail’s routing system makes clever use of blocks to provide a hierarchical, declarative URL map that just makes sense to read. I used to design URLs in an indented text file and then map it to a list of regexps, but the routes.rb file is close enough to a spec and doesn’t require me to even think about regexes, ‘nuff said.
Authentication is hard. Really, really hard. And boring. Really, really boring. But important. Really, really important. Everyone knows that the sign-up funnel is critical to get right and security is easy to get wrong. Most quality sites have a little bit of domain-specific special sauce in their authentication model. Trivial sign-up and log-in forms just don’t cut it. One size simply does not fit all for authentication front-ends, but the authentication back-ends tend to be pretty repeatable. Authlogic turns repeatable into re-usable, without the baggage of views you’re going to need to rewrite anyway. Thinking about authentication as CRUD operations on a user-session model blew my mind slightly. I had a full authentication system tuned to my needs up and running within two hours.
I hate ACLs. Role-based authorization simply has too much impedance mismatch for most problem domains. CanCan is a clever little library which makes zero assumptions about how permissions are represented. Simply declare a list of everything a user can do and how to tell if they may. Query with the can? function, or assert with the authorize! method. Beautiful.
Rope to Hang Yourself: Ruby Itself
One keyword in my previous post triggered much discussion: magic. The concept of magic is a topic for a whole ‘nother blog post (as I’ve already been hung a few times), but as several commenters pointed out: it’s all just Ruby. Between mixins, include, require, blocks, method_missing, symbols, and many other features, Ruby is a very capable internal domain specific language development toolkit. Most of the time, you don’t want a DSL. If you’re not an expert in both the host language and the DSL, there is almost certain confusion and maintenance danger. Most projects are either small or distinct enough to justify writing more verbose code that can more readily be understood by successors or even your future self. The gains of a DSL do not always outweigh the costs. Python excels at not supporting DSLs; it is basically executable pseudocode. However, when it comes to a task as common as web application development, it’s worth the time to develop or learn a DSL or two. Rails is loaded with DSL features and “magic” behavior that increases the learning curve, but also increases peak productivity.
These sites have been invaluable: The Ruby Toolbox, RailsPlugins, Railscasts. The quantity and quality of Ruby libraries on Github continues to impress. The educational infrastructure is extensive. Somehow, the Ruby community seems to consistently be at the forefront of the biggest trends in software development. Much like Rails compared to other frameworks, the community distinctions are subtle, but meaningful. For example, Rubyists championed Git while Python adopted Hg. To the untrained eye, they are virtually identical tools, but extensive experience with both has convinced me that Git is significantly superior. I’m new to the community, but it seems like Rubyists tend to insist on quality and bet on the winning horses.
Other Random Things
- Static files are served with version stamps for better caching behavior
- Console and file logging are usefully configured by default
- git push heroku
- ActiveMerchant looks awesome
- Only been working with Rails for two weeks; lots more goodness to uncover
Just who the hell do I think I am?
I’m nobody. Just some opinionated computer geek working on a start-up. Not unlike many of you! My co-founder and I are currently participating in TechStars Seattle and hope to launch something killer come demo day, November 11th, 2010. We’ve got a grand vision for next generation enterprise collaboration software, but we’re starting small by focusing on making weekly status reports less painful and more useful. More details soon, but please visit http://www.thinkfuse.com. Thanks!