Seems like Couchbase Lite / Mobile deliberately keeps the attachment metadata read-only by exposing a read-only immutable data structure in the interface. There have been times where I have wished to be able to write attachment metadata that feels like it belongs with the attachment rather than in the associated document – things like the last-updated date of the attachment. Is that something you have considered and rejected?
The attachment metadata is really just a property named
_attachments that you can change just as you’d change any other property. (But don’t mess with any of the properties that are already in there, like
encoding. Well, you can change
It’s unclear whether user-defined properties will work. Couchbase Lite and Sync Gateway will ignore properties they don’t know about, and will preserve them when updating the document. However, I don’t know what other compatible databases like CouchDB, PouchDB or Cloudant will do.