HttpDo | Lightweight package providing you with means to host | Runtime Evironment library

If I were you I would try to get something simpler working. Can you get this working with a more basic piece of XML? Can you hard-code the XML and see if that works?

If you google your error "Converting circular structure to JSON at JSON.stringify" you'll get a ton of results. Basically you can't convert an object to JSON if it contains circular references.

Then looking at the P5.js reference, you'll notice that the p5.XML type contains a circular reference with its getParent() function.

This is the cause of your error: the httpPost() function is trying to convert your XML into JSON, which it can't do because it contains a circular reference.

To fix your problem, you have a few options:

• Track down why the httpPost() function is converting XML to JSON. This smells like a bug, so I'd do some more debugging to figure out what's going on.
• You could convert your XML into a string. The getContent() function might help here.
• You could load your XML as text or as bytes instead of loading it as XML.

The above are just guesses because I can't actually run your code, but hopefully this gets you unblocked. Good luck.