Adding HTML elements in cells

I want to be able to add HTML elements into a cell (eg links, buttons). I’ve already seen this tutorial ( … _grid.html), but I am really confused on this implementation. My table is built by calling the server and the server returns JSON data. The example shows how to do it with XML, but how is it done with JSON?

Also, why was it badly implemented this way? DatatTables HTML cell implementation is extremely easy and intuitive where you can actually code your own HTML elements, instead of using the carrot delimiters. What if I wanted the element to have a unique ID or class? How would I do that with DHTMLXGrid?

html elements can be defined in json with no problem.
Could you provide with the snippet of the used json.