Grails. JSON. his methods?

I was up all night looking for information on how to use JSON in Grails. And I found the information that in JSON closure, we can use only one method - array - no other. is it true?

and next small question:

i find here: http://www.jiramot.info/mini-guide-to-rendering-json-with-grails example:

render(contentType:‘text/json’){
        collection{
                pair(name:‘value’)
                pair(name:‘value1′)
        }
}

Will be rendered as:

{collection:[{"name":"value"},{"name":"value1"}]

but when i try do it, i have this result:

{"collection":{"pair":{"name":"value1"}}}

What conclusion can we do? i do some wrong or wrong example on site?

try

render(contentType:‘text/json’){
        collection {
                array {
                   pair(name:"value")
                   pair(name:"value1")
                }
        }
}

JSON rendering in Grails is much easier...

def foobar = [ fooArray: [ 1, 2, 3 ], bar: [ b: "bbb", a: "aaa", r: "rrr" ] ]
render foobar as JSON

results in

{"fooArray":[1,2,3],"bar":{"b":"bbb","a":"aaa","r":"rrr"}}

Just create an appropriate Groovy structure and render it as JSON.