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ActivityPub C2S: No way to request newer page of the Collection

Use case:

  1. Upon request of e.g. https://pleroma.site/users/AndStatus/inbox I'm getting the "first" page of the OrderedCollection. It has:

1.1. "id" url (e.g. https://pleroma.site/users/AndStatus/inbox?max_id=9g2HcpbAjx37E1U90y )

1.2. a link to the "next" page, i.e. to the older activities of this endpoint. E.g. https://pleroma.site/users/AndStatus/inbox?max_id=9gmg7FVl50VMgeCw0u

  1. Some time later I want to check for newer items, but I don't have any working link for this:

2.1. If I try to retrieve a page that I retrieved earlier (see point 1.1. above) using URL from its "id" property, I'm getting "INTERNAL_SERVER_ERROR (500)" (This is a bug, but it's not so important for this issue ticket)

2.2. No "prev" property is defined, which could logically point to the "future" page - this is a the main problem.

2.3. So the only way for this check is to request initial endpoint page: https://pleroma.site/users/AndStatus/inbox that results in unnecessary duplicated requests and data transfers, and complicated syncing logic.

Please add the "prev" property to each page, including "first" page, to allow requesting "future" pages (updates).

Link to the spec (BTW it does NOT say that the "first" page cannot have "prev" property): https://www.w3.org/TR/activitystreams-core/#dfn-collectionpage

Edited by Yuri Volkov