rack_save.RdSerialises data to a temporary JSON file and uploads it to backend. This
is a convenience wrapper around rack_upload() that handles JSON
serialisation automatically.
rack_save(backend, data, name, id = NULL, ...)A rack backend object (e.g. a pins_board).
An R object to serialise and store (typically the session list returned by the blockr session machinery).
Character scalar. The board name. Backends that derive a storage
handle from it (e.g. pins) use it only when creating a new record
(id = NULL); for an update it is ignored in favour of id.
A rack_id identifying an existing record to add a new version to,
or NULL to create a new record (the backend mints the storage handle).
Additional arguments forwarded to rack_upload().
A rack_id object identifying the newly created version.
rack_load() for the complementary load function,
rack_upload() for the underlying upload generic.