[oslc-core] OSLC Core properties for ui previews - suggested change to Core Spec Appendix A

[Nick Crossley]

For performance reasons, it is desirable that a single http GET request on
a resource provided all the information necessary for a human-readable
summary about that resource, and that a query can get all the information
necessary for a human-readable display of a table of the results.

The common properties defined in Appendix A of the Core 2.0 spec,
http://open-services.net/bin/view/Main/OSLCCoreSpecAppendixA, include many
properties that help with this, including for example oslc:shortTitle.
Unfortunately, there is one key omission: oslc:icon.  The oslc:icon
property is defined as part of the compact representation of a resource in
the Core IU Preview page at
http://open-services.net/bin/view/Main/OslcCoreUiPreview, and is also
listed as a property of the publisher property of the service provider and
service provider catalog resources, but is not included in Appendix A as a
common property.  Many OSLC domains have taken the set of properties listed
in Appendix A as the basis for defining the recommended properties for that
domain; the result is that few (if any) OSLC resources today include the
oslc:icon property in the standard representation, but include it only in
the compact representation.

The consequence is that an application that wants to show the icon in a
query results table has to perform an additional GET to read the compact
representation.

I propose that we add oslc:icon to the list of common properties in
Appendix A, and recommend its inclusion in the standard set of properties
of OSLC resources from all domains.  For completeness, we should probably
include oslc:iconAltLabel and oslc:iconTitle.

I do not believe it is necessary to include oslc:smallPreview or
oslc:largePreview in the Append A list, since we would not want the actual
preview contents to be included in the default representation of a
resource; we want that to be obtained by a separate GET.  We could achieve
that by including these two preview links in the Appendix A properties, but
with the recommendation that they be normal externally referenced resources
with an http URL - but that has no performance advantage over the current
technique of having those previews embedded as inline resources in the
compact representation, and has the disadvantage of requiring these
resources to have an externally addressable URL.

Nick Crossley.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://open-services.net/pipermail/oslc-core_open-services.net/attachments/20131106/f577effb/attachment-0003.html>