DHTMLXForm Select Connector with JSON

I want to use the DHTMLXForm select Connector (docs.dhtmlx.com/connector__php__ … ector.html) but I do not use your PHP server side code, I write my own. I have it working with XML but I’d rather use JSON. I can’t seem to figure out the format. What is the JSON format I need to return?

Hi

here is common information
docs.dhtmlx.com/form__json_structure.html

here is controls list (it contain json description)
docs.dhtmlx.com/form__controls_list.html