I copied the logic from grails JsonBuilder: https://github.com/grails/grails-core/blob/master/src/java/grails/util/JSonBuilder.java. Not a groovy expert, but wanted to get the same "json feeling" as in grails.

for me the following worked fine:

1. Making GXContentBuilder extends GroovyObjectSupport.
2. Changing getProperty() method to:
   def getProperty(String propName) {
   if (current?.containsKey(propName)) {
   return current[propName]
   } else {
   return super.getProperty(propName)
   }
   }
   https://github.com/spn/elasticsearch-grails-plugin/blob/master/src/groovy/org/grails/plugins/elasticsearch/util/GXContentBuilder.groovy

Interesting!. I can't really judge the implications of this change because of my lack of groovy knowledge :). Wondering why grails are not doing the same? Maybe it makes sense to ping the grails mailing list?

well, Grails IS doing the same sometimes eg look at https://github.com/grails/grails-core/blob/master/src/java/grails/spring/BeanBuilder.java

(actually, in your case the class is written in Groovy so you don't need to extend GroovyObjectSupport. But it still has to fallback to standard property resolution)

What I mean is that it does not do it for JsnoBuilder, wondering what the reason for that is, and thought it might make sense to ping the list?

That's right. JsonBuilder uses Builder API, which is sort of high-level tree-oriented; it does not require you to manage properties and methods (BuilderSupport class is doing it internally)

I'm sorry, I sent the wrong link to the JsonBuilder used in grails. This is the one ES is based on: https://github.com/grails/grails-core/blob/master/src/java/grails/web/JSONBuilder.groovy .

it looks to me you have a small difference from the original JSONBuilder:
private buildRoot(Closure c) {
c.delegate = this
//c.resolveStrategy = Closure.DELEGATE_FIRST
root = [:]
current = root
def returnValue = c.call()
if (!root) {
return returnValue
}
return root
}

Looking at GXContentBuilder, c.resolveStrategy is NOT commented out. This is a serious difference, because it affects delegation rules (by default, closure delegates to OWNER_FIRST, and owner is "client" code which uses variables).

Right, but then it makes a big difference when used in scripts... . Thats why in the builder you can control what it is (static var...). But, I will change it so the default will be OWNER_FIRST.

Groovy client doesn't bind to any variables outside the closure, closed by 0dfa3dc.