Wednesday, April 18, 2007

Groovy & Grails at JavaOne 07 University

As well as a BOF at JavaOne I'll also be doing a half-day course at the JavaOne university on Groovy & Grails. Check it out here.

Neal Ford: "I would rather write Groovy code in VI than Java code in IDEA"

Interesting and entertaining interview with Neal Ford of ThoughtWorks fame. He has lots of nice things to say about Groovy and Ruby.

The only point I disagree with is his assertion that in Groovy you can only do 80% of what you can do in Ruby in terms of DSL programming. I've never seen a Ruby DSL that couldn't be done in Groovy with a similar conciseness in the syntax. It would be nice if Neal could elaborate on this point.

Tuesday, April 17, 2007

Contrasting Grails SpringBuilder vs JRuby Spring DSL vs Guice

An interesting post by Craig Walls that I hadn't noticed before shows how you can create Spring configs with a little JRuby DSL:

DAOS = [ :ZoneDAO, :EmailDomainDAO, :DayDAO, :PreferenceDAO,
:WhatEverDao... ]
DAOS.each do |dao|
bean(dao, "daos.hibernate.#{dao}Hibernate")

The Groovy version with Grails' SpringBuilder would look like:

def DAOS = [ZoneDAO, EmailDomainDAO, DayDAO, PreferenceDAO, WhateverDAO]
DAOs.each { dao ->
"${dao}"("daos.hibernate.${dao.simpleName}Hibernate") {
sessionFactory = ref("sonarSession")

Another important difference between the two is that Springy, the JRuby version, serializes the JRuby code into XML and then reads the beans from that. We used to do this in Grails, but it had serious performance implications for load time, Grails' BeanBuilder constructs the ApplicationContext programmatically on the fly.

Bob Lee also offered his alternative using Guice:

Class[] daos = { ZoneDao.class, EmailDomainDao.class, PreferenceDao.class... };
for (Class dao : daos)
bind(dao).to(Class.forName("daos.hibernate.Hibernate" + dao.getSimpleName()));

Since Groovy does annotations it is possible to make this code even Groovier:

def daos = [ZoneDao, EmailDomainDao, PreferenceDao...]
daos.each { bind(it).to(Class.forName("daos.hibernate.Hibernate${it.simpleName}") }