ActivityPub

Appendix B. Activity Streams 2.0 Properties

This appendix describes each of the important properties defined in AS2. I cover what type of object they can apply to, what values they can have, what they’re used for, and what to watch out for. I also give tips for publishers and consumers to maximize interoperability.

For each property, I include the following information:

Information	Explanation
Type	The type of object this property applies to
Value	The types and typical values of this property, including whether plural values are allowed
Group	A rough category of related properties, created by me
Importance	A subjective evaluation of the importance of this property
Notes	My notes on the property
To publish	Tips on publishing objects with this property
To consume	Tips on consuming objects with this property
See also	Related properties that may be worth considering

Most of the value types are typical of programming language types: strings, integers, floating-point numbers, Booleans. Many are URI or URL types. Most important, the id type can be an object, a URL, or an array of objects and/or URLs. Handling ids or JSON objects is discussed pretty thoroughly in Chapter 2, including how to handle each of the value types.

I wish I could say that I love all the AS2 properties equally, but they aren’t my kids, so I don’t have to do that. Some of these properties are under-defined and not easy to use. In the notes and tips, I try to err on the side of interoperability ...