Flatten a Map of Maps

A question came up that interested me, someone had a map that contains children of possibly lists of other maps, and they wanted to flatten all these maps to count all the values contained in this map of lists of maps. I just used a recursive closure to collect all the values of the maps and lists, flatten that into a list and then an inject (fold) to count up the values.

def collector
collector = {item -> item.collect {element -> element.value instanceof Map ? collector(element.value) : element.value}}

assert 4 == collector([a: [q:1, w:1], b: [e:1], c: 1]).flatten().inject(0) { temp, val -> temp + val.value}
assert 3 == collector([a: [q:1, w:[z:1, x:1]]]).flatten().inject(0) { temp, val -> temp + val.value}

Grails logging debug from your controller logback.groovy

To get your controllers and services logging debug messages edit your logback.groovy. Just add your package structure, for instance if your package structure was com.myapp

root(ERROR, ['STDOUT']) // Sets log level of all
logger('grails.app.controllers.com.myapp', DEBUG, ['STDOUT'], false) // Turn on debug for all your controllers
logger('grails.app.services.com.myapp', DEBUG, ['STDOUT'], false) // Turn on debug for all your services