[JMAP] Re: JMAP for Calendars comments

[Mauro De Gennaro <[e-mail]>]

Hi Neil,

Sorry for yet another email, I promise this will probably be the last one for a while!

> - Section 5.11.1 (Filtering): Some filters accept null as an argument. In some cases this makes sense (to indicate absence of a value), but for others like text, before, or after it doesn’t really make sense.

Please disregard this comment, it’s been a while since I implemented JMAP Core and had forgotten that a FilterCondition object can contain multiple properties.

I also have two new comments:

- Calendar deletion: I think the spec should specify whether scheduling messages are sent when an entire calendar is deleted. Personally, I don’t think sending them is necessary, but it might be useful to have an option similar to sendSchedulingMessages in Calendar/set, just for consistency.

- Section 5.3 – Attachments: The blobId property mentioned there is not currently registered with IANA.

And finally, I wanted to clarify and summarize the discussion about ParticipantIdentity from my previous message. My understanding is that ParticipantIdentity tells the server which calendarAddress values belong to a user, so that permission checks can be applied correctly. I don’t think having a ParticipantIdentity/set method is inherently problematic:  just like with email identities, the server can reject any calendar addresses that it determines do not belong to the account (which is covered in section 3.3). As for permissions, my understanding is that ParticipantIdentity objects can only be retrieved and modified by the account owner (otherwise the spec would need to define how to set permissions for them).

My confusion mainly comes from how calendar addresses are handled in CalDAV. So let me ask a related question: how can one calendar user discover the principal ID or account ID associated with a given (local) calendar address? If the calendar address is simply an email listed under a Principal object, that’s straightforward. But consider this example:

- John’s Principal lists [e-mail] as the email address.
- John also has two ParticipantIdentity objects: mailto:[e-mail] and mailto:[e-mail].

Now, suppose Jane sees mailto:[e-mail] listed as a participant in an event and wants to query John’s availability using Principal/getAvailability. How can Jane determine which principal ID is associated with that address, given that it’s defined as a ParticipantIdentity under John’s account? The Principal/query method does not currently allow querying by calendar address and Principal objects can contain just one email, so how should a client resolve that mapping?

Please let me know if I’m misunderstanding something here, and apologies again for the flurry of emails!


Best,
Mauro