DevelopingStorm

Wednesday, December 17, 2003

I finally got a chance to play around with Groovie's GPaths. I encountered some confusion in using them but did surmount the problems with the help of some System.out.println statements (why no println command?). I started my exploration with a another look at tree syntax but this time I used a NodeBuilder instead of a MarkupBuilder. This change let me build a tree of objects instead of output some markup.

 
protected createTree() {       
    builder = NodeBuilder.newInstance()
        
    root = builder.people() {
        person('James') {
            location('London')
            projects {
                project('geronimo')
            }
        }
        person('Bob') {
             location('Atlanta')
             projects {
                 project('drools')
                 project('jessy')
             }
        }
    }
    return root;
}

I then tried to build a Gpath that selected a person who participated in the jessy project.

tree = createTree()
s = tree.person.find { 
    it.projects.project.any {
        return it.value() == 'jessy'
    }; 
}

This snippet finds a person who has any project that has a value of 'jessy'. If I call System.out.println(s) I will see a value like:

person[attributes={}; value=[Bob, location[attributes={}; value=Atlanta], 
projects[attributes={};value=[project[attributes={}; value=drools], 
project[attributes={}; value=jessy]]]]]

I did find it confusing that I was required to call .value() in the comparison. I was assuming that some sort if automatic string transformation would occur when I compared node to string.

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