Normal form submission vs. JSON

Question

I see advantages of getting JSON response and formatting in client side but are there any advantages by using JSON for form submission compared to normal submission?

Answer 1

I am actually wrestling with the same problem. My use case requires that a potentially complex tree to be posted to the server. Some framework are able to decode two dimensional arrays as form attributes (Spring WebMVC is one I know of). Even so, this only helps you in the specific case when you are sending a nested array. The inherent nature of name-value-pair makes it unsuitable for transmitting a tree more than one level deep. In the past, I have used hacks like sending URL-encoded JSON as attribute value:

val0=%7B%22name%22%3A%22value%22%7D&val1=something&val2=something+else

However, this approach gets messy and difficult to debug when the object becomes more complex. In addition, many frameworks provide tools that automagically map JSON form post to objects (e.g.: Jackson for Java), it seems obtuse not to take advantage of these tools.

So ultimately, the choice rests on the complexity of the object you are sending. If the object is limited to one level deep, use straight name-value-pair; if the object is complex and involves a deeply-nested tree, use JSON.