When I got home I realised that we were shown a fixed demo in that many of the features didn't really work when building on Google App Engine and Google Web Toolkit. Not a problem as all developers know we are used to living on the cutting alpha-beta edge of software where great new features come with one huge caveat, they occasionally don't work.
That was then and this is now. Like Sushi which I try every 6 months just to confirm that I still am not a huge fan, it doesn't taste of anything right?, I try the latest version of Spring Roo.
The Upgrade Path
Let me just say that I love SpringSource they provide a lot of excellent tools for the Java developer and the Spring Roo documentation is no exception. The upgrade path is very easy, unpack the latest Spring Roo to a directory of your choosing, amend your $ROO_HOME variable in .profile (Mac OSx) and then re-establish the symbolic link to the roo command line. (sudo ln -s $ROO_HOME/bin/roo.sh /usr/bin/roo)
Done and done!
The Bleeding Edge
So I tried Spring Roo 1.1.5 and it was giving me lots of errors with trying a GWT-GAE project. It seemed as equally unreliable as I had tried with previous versions. Let me just add if you are using a standard database such as MySQL or any of the other persistence options, I believe Spring Roo works just fine. The problems I usually run into are related to the peculiarities of Google App Engine and how Roo handles those.
Since most of my current projects are currently in the GAE-GWT sphere and Roo advertises that it is suppose to work in this area, I decided to upgrade to the very latest Spring Roo, so I delved into the nightly builds and installed (1.2.0.BUILD-SNAPSHOT [rev 176e407]).
Go for 1.2.0 Its Much Better
After building a couple of projects with 1.2.0 I can honestly say this is the best version yet by far. Why? Well it appears to work this time for GWT-GAE projects. Most of my personal work is done on Google App Engine. This might change as I am not really liking the new billing restrictions but we will see how those actually plan out when implemented.
I typically build small projects that utilise some sort of reference between domain objects and then build a GWT project and then test it to see if it actually works. I will deal with deployment in a different post. What is great about Roo is that you can amend say the domain objects and the auto UI will get updated automatically. Simply add the line : private String userName; : to your domain object, boot up Roo and it auto creates the UI amendments needed. Pretty stunning. I haven't yet got to work out how you prevent it from doing this should you want to improve the UI, but I am sure that will come soon.
The project I have built it is that for a taxi company to take bookings. It includes three domain objects Contact, Booking and Journey. A booking can have one or more contacts, and one ore more journeys.
A Spring Roo GAE GWT project that works
Here is the contents of my Roo file, hopefully this will help you work with your project.
project com.prestige.booking persistence setup --provider DATANUCLEUS --database GOOGLE_APP_ENGINE --applicationId PrestigeBooking enum type --class ~.shared.domain.ContactType enum constant --name Booking enum constant --name Billing enum constant --name Passenger entity --class ~.shared.domain.Contact --testAutomatically field string --fieldName fullName --notNull field string --fieldName email field string --fieldName phoneNumber field enum --fieldName contactType --type ~.shared.domain.ContactType entity --class ~.shared.domain.Booking --testAutomatically field reference --type ~.shared.domain.Contact passenger entity --class com.prestige.booking.shared.domain.Journey --testAutomatically field date --fieldName journeyDate --type java.util.Date field string --fieldName startAddress field string --fieldName endAddress field string --fieldName startTime field reference --fieldName booking --type com.prestige.booking.shared.domain.Booking loggin setup --level INFO web gwt setup
Next Steps
If you have used Roo or have done some interesting things with a Roo project please get in contact. I have yet to explore the AddOns or detailed more information on the workflow in a Roo project that goes from prototyping to real world application. Get in contact and lets document some Best Practices for this awesome product.
