On typical photo silos that you can POSSE to (Facebook, Flickr), in addition to liking & commenting your friends can tag people they know in those posts.

On Instagram, you can add person-tags to your photos after the fact as well as during posting.

Bridgy should backfeed these silo person-tagging interactions just as it backfeeds comments for reasons that are helpful to the publisher particularly for photos:

https://indiewebcamp.com/photo#backfeed_person_tags

Originally requested: http://indiewebcamp.com/irc/2015-09-01#t1441140760078

Bridgy can do this by creating synthetic tag-reply posts (similar to reply posts), with "tag-of" markup and person-tag "u-category h-card" markup as documented here:

https://indiewebcamp.com/tag-reply
https://indiewebcamp.com/person-tag

And then send a webmention back to the original post like the existing Bridgy backfeed support.

If it's possible for Bridgy to figure out silo profile userid -> indieweb URL for each person-tag, that would be even better. A couple of thoughts:

• Bridgy could use its own database of Auth'd in users from those silos to determine what their indieweb site it
• Bridgy could do rel=me discovery on the silo profile to figure out their indieweb site (and perhaps cache that?)

This would be above and beyond just supporting backfeeding of person-tags, hence separate comment.

It might also be reasonable to put all the burden (freedom of choice) of converting a silo profile URL (e.g. FB/Flickr profile) to the indieweb equivalent. Capturing both possibilities here for consideration.

👍 thanks for filing!

re discovering indieweb urls, you pretty much covered it. twitter, google+, and instagram actually all let you fetch anyone's profile via API, so we'd only have to do rel=me discovery for facebook. (not sure about flickr.)

current silo support::

• Facebook: yes
  , via /photo/tags (needs testing) and tagging_user.
• Flickr: yes, via photos.people.getList etc.
• Twitter: no. photo people tags aren't exposed in the API.
• Google+: no. G+ doesn't have person tags distinct from mentions. Google Photos probably does, but it's mostly a separate product now.
• Instagram: no.

one interesting wrinkle here is that we'd want to distinguish between the user's own tags and tags created by other people. ideally we would only backfeed the latter.

... except i suspect the APIs may not differentiate between them. I'll find out.

yay, Facebook tells us, but i haven't yet found a way to determine a tag's creator in Flickr, either in photos.people.getList or nearby. @kylewm can you confirm?

I think you're right, I don't see a way to see who created a tag in the Flickr API

approaching from another direction you could poll flickr.people.getPhotosOf and backfeed any new photo of a person that comes from another account.

https://indiewebcamp.com/tag-reply doesn't have any indieweb examples. it's possible that no one consumes u-tag-of yet.

@snarfed re:

we'd want to distinguish between the user's own tags and tags created by other people. ideally we would only backfeed the latter.

I think I disagree. Even if you @-reply to your own tweet, you get backfed the @-reply.

Similarly, if you person-tag your own POSSE copy of a photo, you should get backfed the tag-reply.

no one consumes u-tag-of yet.

Unfortunately not. I'm not sure how to bootstrap this as a publisher.

Added sentence in the issue description about being able to add person-tags to your Instagram photos after the fact, as another case where you would want the person-tags backfed to your original photo post.

Slight issue name tweak to indicate specific scope of backfeeding to posts