RE: [search-ws] [Issue] Search response can only return XML records

["Matthew J. Dovey" <m.dovey@jisc.ac.uk>]

>So we agree then that recordData element can contain a XML structure.
>That was my point. Indeed an XMl structure can contain binary content
>but that would be left to the application schema under current strawman
>spec. 

Indeed - but how the record data is handled in general is always left to
the application schema. That is the extensibility of the protocol - the
protocol itself is mute about what appears under recordData (the only
stipulation is that it must have a namespace qualified top level
element). Which record structures can be returned can be determined by a
client via explain, which record structure a client would prefer can be
suggested via the recordSchema parameter in the request. Ensuring that
clients and servers expect common formats is the role of a profile.

>What I was proposing is for spec to define a type hierarchy for a
record such that
>Binary records may easily be returned by server without requiring any
help from 
>application XML schema. See an abstract example below:

I'm not sure what that gets us - given we'd need a means in explain to
indicate a server will return binary data direct, and a mod to the
request to request binary data etc.

We could always create a new normative record schema with a single top
level element called say blob which has a mandatory attribute
xmlmime:contentType - however I'd really like to see a use case where
you do want to return just a binary blob, rather than a binary blob with
additional metadata where an XML structure containing both metadata and
binary would make more sense.

Matthew