Typing of DataPart

[sfitts]

If I'm reading the definition of the DataPart schema correctly, then the data property is typed as a JSON object. This leads to a couple of questions:

• The comment in the schema says, "The structured JSON data payload (an object or an array)." Given the declared type this does not appear to be true. Is this simply an error in the comment or was the intent that data should be allowed to be either an object or an array.
• Why isn't data typed as to allow any JSON root element? Once upon a time JSON restricted the root to object and array, but that hasn't been true since RFC 7159.

Assuming we are restricted to just producing JSON objects, what is the intended way to transmit other outputs? Should an array be broken down into one Part per item? What if the items are not themselves JSON object values? Sorry if this is all obvious, but I couldn't find any clear explanation of the intent here.

[DracoBlue]

One advantage of using the data as dictionary - with a string key and value as any typed - is if you think about having multiple DataParts appended for the same artefact.

Think of streaming the flight number and airline as:

{
  "no": "AIR123",
  "operator": "Air Line"
}

and giving the price a little bit later like this:

{
  "price": "120",
}

... this makes it possible to merge the resulting data. If it wouldn't be a dictionary - you would have to define how appending (merging?!) them should look like.

IMHO having it as dictionary is fine. If you want to put anything else into it give it a good key :). What do you think?

[sfitts]

I tend to feel that it is a bit too restrictive/arbitrary. We want to use the agent artifacts to represent elements from the underlying application domain (which for us might be anything) and it is not uncommon to have artifacts which are not naturally represented as dictionaries. Forcing the agent to always wrap these, while possible, ends up being extra work for both the agent and the client (since the artifact is neither produced nor consumed as a dictionary). Hope that makes some sense.