Grails Kick - er, Quick Start

Well I'll be. I've just completed the Grails Quick Start and I must say, I almost heard the angels. They weren't singing yet but I think I heard them warming up their voices.

The Grails Quick Start is fairly intuitive to follow. Just do what the instructions suggest and you should be fine. I won't run you through it blow by blow because it's online for your own viewing convenience at: http://grails.codehaus.org/Quick+Start, but this is a précised summary of what I did.

I ran a script to create the project outline. That worked as advertised. At this juncture the Quick Start points out that you can change the data source for your brand spanking new web application if you so desire. Or it'll start with an in-memory HypersonicSQL DB for your convenience so you can get up and running immediately. I'm good with the HSQL DB for now. I'm just having fun right now anyway.

Following this you create a domain (or model) class, using a Grails script. The Quick Start offers a 'Book' domain class with a 'title' and 'author'. Just do that. Then in a Groovy bootstrap script you setup some test data. Easy-peasy. Done.

Lastly, like any well-behaved MVC prodigy, you need to create a controller for your model. Again, call your controller 'Book', and Grails will create a 'BookController' for you. Schweet. That worked too! So far so good.

(Quick aside: the Quick Start indicates you can do a 'grails generate-all' and give that the 'Book' name and it'll create your model and your controller, but I did each step on its own. Now that I think of it, I had to do a 'grails help' to figure out that they do a 'grails create-controller' because the Quick Start doesn't indicate that, but I'm sure generate-all will accomplish the same thing at the end of the day.)

Now of course you need to have view stuff, but like Rails, Grails offers the concept of 'scaffolding' which provides the basic structure for CRUD (CreateReadUpdateDelete) operations on your brand spanking new domain/model class. So a quick edit of my BookController to tell it to scaffold the Book model class, and I'm ready to rock and roll.

The rock and roll part is as sexy and as simple as typing 'grails run-app' from my project root folder. Baddabing! My web application launches. I haven't yet looked at what Grails uses but it's obviously a lean instance of Tomcat or Resin or some such. That's irrelevant to me at this time, since I'm itching to find out whether my browser can make sense of: http://localhost:8080/myproject/book/list.

I type in the URL, hit Enter and wait with pregnant anticipation.

Whooooot! It works!

I am impressed. Like I said earlier, I'm sure I heard the angels doing voice warm-ups. I get a list of the books I typed into the bootstrap thingy, and I can add books, delete books, or go to a home page for my web application that indicates which controllers exist in my web application. And I didn't type a single line of view 'stuff'. This is neat! It took me all of about 2 mins to get a Java web application up and running. I'll be done with my new project in about 4 hours. Okay, okay, I'm getting ahead of myself. But so far so good, which is not often the case when I play with open source (i.e. open sores) stuff.

My curiosity now wants to know how Grails will cope with changes to my domain, controllers and views. That's still a bit of an unknown. Onwards we march.