IWS Rest Post, Response Code, and Best Practices on Error

For more info, see thread below in link..

I have a POST created in IWS that has a struct (JSON) as an Input parameter. It also uses httpStatus, and httpHeaders. We also return 2 character messages. When everything is goes well, we return 200 and in the 'body' that is returned, we receive the contents of successMessage and errorMessage in JSON formats.

We've tried to add validation on say items and locations in the Order (JSON) struct before actually doing anything in the code. I was thinking we could set the httpStatus to 4xx, set errorMessage to some string, and IWS would return the errorMessage just like if 2xx. We don't seem to get anything back in the response.

Any thoughts? Thanks.

=======================================================================================

Procedure Interface...
Dcl-pi createOrder;
Order likeds(orderInfo);
httpStatus int(10);
httpHeaders char(100) dim(10);
successMessage char(100);
errorMessage char(100);
End-pi;

https://stackoverflow.com/questions/942951/rest-api-error-return-good-practices?noredirect=1&lq=1