Querying spotlight with MacRuby

spottest.rb

def performSearch(pred, &cb)
  search = NSMetadataQuery.alloc.init
  search.predicate = pred 
  search.searchScopes = [File.expand_path("~")]
  
  NSNotificationCenter.defaultCenter.addObserverForName(
    "NSMetadataQueryDidFinishGatheringNotification", object:nil, queue:nil,
    usingBlock: Proc.new {|n| n.object.results.each {|r| cb.call(r) } })
    
  search.startQuery
end

pred = NSPredicate.predicateWithFormat("kMDItemDisplayName like[c] '*whatever*'")
performSearch(pred) {|r| puts r.valueForAttribute("kMDItemDisplayName") }