VOSpace questions

[Grégory Mantelet]

Dear VOSpacers,

With an intern, Grégory Adam, we are starting to look into the VOSpace 
spec. and we have some (simple, I hope) questions on the document (2.1).

--------------
*
1. About getNode and its parameter `detail=min`:*

     The VOSpace document says:

>     - min: the returned record for the node contains minimum detail
>               with all optional parts removed – the node type should
>     be re-
>               turned

     If I try to sum up: the "optional parts" are everything except 
<vos:nodes> in case of a ContainerNode. So, it means that apart from the 
node type (attribute xsi:type) a non-ContainerNode will be empty.

     Is it correct?

     If yes, there is a mistake in the example given in 6.3.1: the XML 
elements <vos:properties>, <vos:accepts>, <vos:provides> and 
<vos:capabilities> should not be returned. According to the XML schema 
they are optional.
     Or are they optional only if empty?
     Or because "SHALL" is used instead of "MAY" (in 3.1, page 13) it 
make them mandatory if not empty?

--------------

*2. About getNode and its parameters `uri` and `offset`:*

     The VOSpace document says:

>     If a “uri” and “offset” are specified in the request then the
>     returned list
>     will consist of the subset of children which begins at the node
>     matching
>     the specified value of the “uri” parameter and with cardinality
>     matching the
>     specified value of the “offset” parameter drawn from an ordered
>     sequence
>     of all children. The ordering is determined by the server but
>     results must
>     always be drawn from the same ordered sequence.

     When it is said "which begins at the node matching the specified 
value of the “uri” parameter",
     does "begin" mean "the string begins" or "the returned sublist must 
starts with"?

     For instance, in the given example:

http://server.example.com/vospace/nodes/mydir?detail=min&*uri=vos://example.com!vospace/mydir/file3401
*
     * Should the `uri` filter be interpreted as all files whose name 
begins with "file3401" in the directory "vos://example.com!vospace/mydir"?
/(e.g. "file3401a", "file3401b", ...)

/* If yes, the example in 6.3.1. should be fixed./
/
     * Or should it be the sublist of all children starting from the 
child "file3401"?
/(e.g. if the complete ordered list is [file3399, file3400, file3401, 
file3402, file3403], the returned list would be [file3401, file3402, 
file3403])/

--------------

*3. About getNode*

     Using the same example as in the document, if I run the following 
request:

curl -v "http://server.example.com/vospace/nodes"

     Should it give me the list of all child nodes at the root of the 
VOSpace (as if the root is itself a ContainerNode)?

     Sorry for the possibly stupid question, but it is just to be sure.


--------------

*4. About Properties, Capabilities and Views*

      Properties, Capabilities and Views may have the following attributes:

         - DisplayName
         - Description
         - UCD /(only for Properties)/
         - Unit /(only for Properties)
/        - MimeType /(only for Views)
/
     But none of these elements appear in the XML schema (and they 
appear in no example). The XML schema does not give enough flexibility 
to insert additional information like these.

     So, we wonder how to represent them in the XML and where? How can 
they be discovered?
     Have we missed something?

--------------

*5. Existing VOSpace services and clients*


     I searched in the VO Registries, but I did not find a lot of 
(still) active VOSpaces apart from the following ones:

         - ESA (https://vospace.esac.esa.int/vospace/)
         - CADC/Canfar 
(https://www.canfar.net/storage/list/<https://vospace.esac.esa.int/vospace/>)

     Are there more?

     Similarly, is there any know (generic) client?

--------------

Thank you in advance for your help.

Cheers,
Grégory

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ivoa.net/pipermail/grid/attachments/20200506/a9a8376d/attachment.html>