Question

Let’s say that a request is sent to server via xhrPost and server finds that request needs more information to be processed (for example a variable is missing), so, a response is sent back to client informing that request may have not been completely processed and this message is shown in a dialog box.

I was doing it sending from server an HTTP 202 status code, which I believe is not correct, and treating it on load function, where this message was displayed on a dialog box. But if I respond with some HTTP error code (ex: 400) the error is displayed in console (Note: in this case the message is treated in error function), as well as in my dialog box.

What is the best and correct way to do it?

Answer 1

Note that it is called a load handler, not a success handler.

The load hander is for valid, well formatted responses. These can contain a verity of status codes generated by your server side app that indicates success, failure, or something in between.

The error is just that, the server blew up while trying to process the request and whatever you get back is probably not something your widget was written to expect. For this reason, I recommend using the same error handler across your whole app.

The dojo documentation states:

Sometimes xhrGet calls will fail. Often these are 404 errors or server errors such as 500. The error parameter is another callback function that is only invoked when an error occurs. This allows you to control what happens when an error occurs without having to put a lot of logic into your load function to check for error conditions. The first parameter passed to the error function is a JavaScript Error object indicating what the failure was. Dojo doc