The child who receives a hammer for Christmas will discover that everything needs pounding – Gerald Weinberg

Fred George’s keynote at “Rails Underground” was titled “Rails is an hammer”. It was along the “grumpy old developer” line that kids today jump to use all these fancy frameworks without considering whether they are appropriate to the job in hand. It’s a fun spiel, and one I’ve levelled against a lot of Java frameworks and libraries. Is Rails really inappropriate for most web applications? No, but it’s worth asking the question.

The main charges against Rails are:

• it does not have a domain layer
• the models are based on relational database tables rather than object design

Does Rails not have a domain model?

This is good point that is not often made. Having MVC not the same as a layered architecture. As Jay Fields “discovered” that his Presenter Pattern was not sufficient for some applications it was Domain Driven Design his team turned to concepts such as Services and Repositories. Nowhere does Rails mandate that ActiveRecord models should be accessed directly by controllers.

Good domain models are tough. It can take a long time working with an application before the right model is discovered. Leaping to a model too early – premature abstraction – often leads to an inappropriate object architecture that it can be difficult to write your way out of and Byzantine back channels are needed for operations that do not fit the original design.

Something that Rails has taught me is how far you can go with just MVC and a good framework. I wouldn’t say this for a typical Java web app, but you ain’t gonna need a layered architecture. Until you do need one. Then won’t be a big deal to refactor towards that, as long as you keep you’ve kept your code clean, DRY, and well-tested.

Are Rails ‘models’ are based on database tables?

This came up in the Scotland on Rails CouchDB controversy, and I dispute that Rails ActiveRecord models represent rows in relational database tables. It’s the other way round: relational databases happen to be the persistence mechanism for ActiveRecord; the database is subservient to the object model. No-one normalises their Rails database; you might fret about keeping your objects DRY and separation of concerns but I doubt you look at your Rails DB worry about repeating attributes. It’s about associations, not relations and join tables.

Admittedly, right now Rails is strongly bound to being back by a RDBMS, and there are some hoops to jump through if you want to use something else. That does not stop a growing number of people using alternatives like CouchDB. The promise of Rails 3 is that it will become trivial to swap in alternative Object Persistence mechanisms, so this will become less of an issue.

Given up on Rails yet?

Fred had some valid points, and it was fun to see how far he could get with vanilla Ruby, Sinatra, and persisting straight to disk. I’m still going to be reaching for Rails to solve most of my web app problems, though. After all it’s a pretty versatile hammer, and there’s a lot of things that need pounding out there.

A couple of months ago I had a one week one trip from Los Angeles, which promised to be a jet-lag nightmare: 5 days to adjust to the 8 hour difference and then fly home to suffer another 5 days. Luckily a couple of days before departure I caught a TV programme in which a theory on how to overcome jetlag was tried out on a couple of racing car engineers flying back from Atlanta to the UK: extrapolating from research on mice, the theory was that by fasting for 16 hours the body’s ‘feeding clock’ takes over from the main ’circadian’clock.

By not eating while travelling, then resuming normal meal times on arrival, we can adjust immediately to local time. The experiment worked on the show and the presenter, a world-travelling journalist, claimed that it had subsequently worked for her.

On the journeys to and from LA I fasted for around 16 hours, and it worked very well for me in both directions. I slept from 22:00 to 06:00 on the first night in LA, and then later and longer on subsequent nights. In contrasts my compadres Alan and Brian both suffered quite badly from jetlag throughout the week. Kevin McDonagh tried the fasting trick on his trip to San Francisco for Google IO with similarly excellent results.

In short, if you are willing to forego eating for a 16 hours, you can avoid days of jetlag. The main points are:-

• do not eat on the journey – the journalist presenting the BBC sleep programme claimed fasting on a 11 hour flight worked for her; I have only tried the whole 16 hour fast.
• drink as much water as you like. I also drank a very small amount of orange juice, coffee, and Gin and Tonic on my flights without disastrous results – your mileage may vary
• start eating at normal meal times when you arrive

Happy travelling, but don’t come complaining to me about your circadian rhythms: it’s all in your own hands.