Attachments and thumbnails

[Mark Hammond]

Something else to consider when we think more about attachments...

The couch raindrop allowed for each attachment to provide "preview" and
"thumbnail" schemas - for example, an "image" attachment would have 2
scaled down copies of the image suitable for displaying inline with the
message. The preview and thumbnail copies of the image could have a
different content-type from the "real" attachment (eg, all image
thumbnails were png, regardless of the image type of the original).

We need to cover this usecase in the new attachment world. Further, it
seems reasonable to assume all attachments and links - not just images -
could have this concept. For example, a link to a youtube video could
also include a "preview image" of the video, a .pdf attachment could
include a preview image which is a scaled down copy of the first page,
etc. We could even go so far as allowing an arbitrary link to have a
snapshot of the web page itself.

Note that I'm not suggesting raindrop needs to provide all such previews
in the short or even medium terms - just that our attachment model
should take it into consideration.

In the short term, I will re-activate the "image thumbnails" extension
so the data is available, even if not in the form it will eventually
take - then we can formalize this once we get back to the other
attachment related discussions we need to have (type vs content-type,
visiblity, etc)

Mark