REVERT TO CONSOLE

Grails is a composed of a stack I like, a combination of technologies I’ve enjoyed using over the last few years- Groovy, HSQLDB, Spring, Hibernate, etc. And the whole seems greater than the sum of its parts, so while I’m complaining about it today, I do so knowing that with future releases Grails could really deliver a great solution.

One thing that many new frameworks are striving to offer these days is a quick startup- you can push this button, pull this lever, and voila, you have a hello world and can build from there. Of course this sounds better than writing a domain class, a dao, a service class, then enter some BS in your web.xml, and wire your beans, and add a *-servlet.xml, configure log4j, etc etc etc. And it is. Except when it doesn’t work.

My initial attempt at creating a Grails project went like this:

• grails create-app created my application.
• import project imported my project into Eclipse. I ended up with 25 or so classes in my base directory.
• grails run-app runs Jetty. I pull up a browser and can see my new site- everything appears to be going great.
• grails create-domain-class Create a domain class. Edit the domain class file, add a few properties. Easy.
• grails create-controller Creates a controller class. Remove the index() method and add def scaffold = domain class.
• grails run-app start my server again. This time I see my controller, click on it.

NullPointerException

The crazy thing is, this is after following directions from the book written by the lead developer of the Grails project! Ouch!

Here’s another example:

The getting started with Grails documentation highlights using Bootstrap.groovy in grails-app/conf as a place to inject test data.

So for example, using a domain class Bookmark, in the Bootstrap.groovy file you could write:

new Bookmark(property1: "value1", property2: "value2").save()

and have the bookmark show up in the Grails scaffolding.

With this approach I ended up with a “NoMethodException” saying that save() was not a valid method for this domain class.

Nice.

Another approach mentioned using the groovy console to add data. I could create an object, such as the Bookmark, but again I could not save it. This time it seemed like after creating it, it could not find the object in the stack.

I will continue to post about this as I find out the source of my problems.

Update 5/28/08: After rereading the extensive “how to set up a Grails project in Eclipse” documentation, it became clear that without disabling the Groovy plugin auto-compilation feature, I wouldn’t have much success. In fact, after last night’s effort I’ve made some nice progress and am beginning to see some similarities between Grails and Seam, at least in terms of work-cycle.

I’m frustrated though, by the fact that grails shell is not working for me. I believe the issue is that I’m using cygwin. It may be time to just switch over the linux entirely.

Update: The “grails console” option appears to work.

Update 5/29/08: One thing I’ve noticed is that given a domain object like this:

class Person {
	static optionals = ['middleInitial']
	String firstName
	String lastName
	String middleInitial
}

In the grails console, you MUST specify the optional property middleInitial in order to successfully create an object. Unfortunately, there’s no warning or explanation in the console. It just doesn’t work without all properties being passed in the constructor.

So this will work:

def p = new Person(firstName: "test", lastName: "test", middleInitial: "m")
p.save()

But this will not:

def p = new Person(firstName: "test", lastName: "test")
p.save()

And neither will this:

def p = new Person()
p.firstName = "test"
p.lastName = "test"
p.save()

But this will:

def p = new Person()
p.firstName = "test"
p.lastName = "test"
p.middleInitial  = "m"
p.save()