HPR3082: RFC 5005 Part 1 – Paged and archived feeds? Who cares?

This conversation took almost an hour, so I split it into two shows:

Part 1 talks mostly about the RFC itself, what it means and why.
Part 2 goes into personal experiences with the RFC and with syndication in general, in particular in the context of web comics. This is part 1.

The why

When serving most RSS/Atom feed readers today, you have to choose: Do you make a complete feed with all the things you ever published, or do you make a shorter feed with just the latest entries?

This is a trade-off with pros and cons, and it seems like a trade-off you have to make, but a solution to let your Atom feed have the cake and eat it too existed already 13 years ago, if only any of our feed readers would adhere to it: RFC 5005, Feed Paging and Archiving

The what

https://tools.ietf.org/html/rfc5005 was published in September 2007

The XML namespace for RFC 5005 elements is http://purl.org/syndication/history/1.0, aliased as fh below.
Section 2 defines the complete feed: It is one document (Atom file) that contains the entire set the feed describes. The document is marked with an fh:complete element.
Section 3 defines the paged feed: It is a series of documents connected with Atom link elements with rel set to the link relations first, last, previous or next.
Section 4 defines the archived feed: It has a subscription document that may change at any time, and a series of archive documents that are expected to have stable contents and URIs. The link relations defined are current, prev-archive and next-archive. The semantics are clearer: prev-archive refers to previously published entries, and because the contents are stable you can stop when you see a URI to a document you already have. Archive documents are marked with the fh:archive element.

The who

In this show I’m talking to:

fluffy

Federated social web:

https://queer.party/@fluffy
Writes and makes things in several creative fields:

https://beesbuzz.biz/
Publ is like a static site generator, but dynamic. It produces RFC 5005 archive feeds, of course:

http://publ.beesbuzz.biz/
Thoughts on ephemeral content vs content worth archiving and how they relate to protocols:

https://beesbuzz.biz/blog/5709-Keeping-it-personal

Jamey

Federated social web:

https://toot.cat/@jamey
Blog:

http://minilop.net/
Made a prototype full-history reader that follows RFC 5005 links:

http://reader.minilop.net/
Made a webcomic reader mostly mentioned in Part 2:

https://www.comic-rocket.com/
Made a WordPress plugin implementing RFC 5005:

https://github.com/jameysharp/wp-fullhistory
Made an RFC 5005 archive feed synthesizer for sites with a predictable post frequency and URL structure:

https://github.com/jameysharp/predictable/

Hosted at https://fh.minilop.net/
Was on HPR 9 years ago, talking about Xorg!

http://hackerpublicradio.org/eps.php?id=0825

Conversation notes

Google Reader was terminated 2013-07-01, all subscription data permanently gone on 2013-07-15:

https://www.google.com/reader/about/
Mastodon had Atom feeds with paging, but the feeds went away when OStatus went away:

https://github.com/tootsuite/mastodon/pull/11247
HTML4 does indeed define the HTML link relations:

https://www.w3.org/TR/html4/types.html#h-6.12

It has prev rather than the previous of RFC 5005, but mentions that some browsers support previous as an alias.
HTML5 also defines the HTML link relations:

https://html.spec.whatwg.org/multipage/links.html

Here previous is a lower-case must for historical reasons.
IANA manages the Registry of Link Relations:

https://www.iana.org/assignments/link-relations/link-relations.xhtml

It references RFC 5005 for the Section 4 relations, but not the Section 3 ones.
RFC 5005 singles out its own Section 3 (Paged Feeds) as the best-effort, loose, discouraged model.

Section 3:
Therefore, clients SHOULD NOT present paged feeds as coherent or complete, or make assumptions to that effect.

Section 4:
Unlike paged feeds, archived feeds enable clients to do this without losing entries.



I’m confused about it in the show, but the RFC is clear that an archived feed has one dynamic subscription document, which points to a chain of immutable archive documents.
Back in 2002, Aaron Swartz published his joke MIME-header-based RSS 3:

http://www.aaronsw.com/weblog/000574

The cultural context at the time and the rivalry between RSS 0.91+, RSS 1.0, RSS 2.0 and Atom deserves a show of its own.