It would be nice to add a sample with two links and sample with two languages for the same
link.
A message may have multiple bodies for different languages and it probably doesn't
make sense to add a metadata if there is no a body with the language. Otherwise it may be
not clear for a client developer if it should be included all the translations of the
metadata. Let's say there is two languages en and de but for the link we have 10
translations.
For the Security Considerations it should be mentioned that this can be used for phishing:
you are sending a link to a fake site but the thumbnails and metadata will say "This
is your bank". Another one problem is that the image URL can be used for tracking so
that when a client tries to fetch it an attacker will see IP of a receiver.
Ideally the thumbnail should be sent inline, for a chat messages they anyway shouldn't
be that big,
The sample has a lot of images and it may be not clear which one to support:
<og:image>https://link.to.example.com/image.png</og:image>
<og:image>cid:sha-256+e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855@bob.xmpp.org</og:image>
<og:image>ni:///shai-256;47DEQpj8HBSa-_TImW-5JCeuQeRkm5NMpJWZG3hSuFU</og:image>
<og:image>data:image/jpeg,...</og:image>
<og:video>https://videos.example.com/video-embed.html</og:video>
Can we have a sample of a real page? Ideally a stable one. Then a client developer can
test and compare results.
And last question: do we have any implementation of the XEP? I may add it to the Spark
(Java+Smack) to test the specification and provide a feedback. But if this was already
implemented I would rather see it in action.