Question

I am trying to build a simple tree like structure of objects and identify the depth level of each object. To do this i have created a recursive function but this function always returns the last results and not the expected total results. I probably store the results in a incorrect place.

def getStructure(anObject, level=0) {

    def results = []

    // [parent id, object id, level]

    if(anObject.parent == null) {
        results.add([0, anObject.id, level])
    } else {
        anObject.children?.each { child ->
            results.add([anObject.parent.id, child.id, level])
    }

    // recursive call
    anObject.children?.each { child ->
       getStructure(child, level++)
    }

    results
}

In my test case i always get the latest run, so i guess the results = [] gets reinitialized every time. How do i store the results from a recursive function?

Answer 1

You need to add the results from the recursive call to the results. Instead of

// recursive call
anObject.children?.each { child ->
   getStructure(child, level++)
}

try this:

// recursive call
anObject.children?.each { child ->
   results.addAll(getStructure(child, level++))
}