Nice work Andy! A few comments: - Could we have some HTTP-rendering examples of how to add/remove Kind instances to/from a collection other than the defining collection? - The section on Navigation refer to Links and Actions, is this the Core base types referred to? The Core Link type has little to do with paging from my point of view. The Link Header in HTTP on the other hand can be used for _both_ representing Core Links and paging. I see how Core Actions can be used to express paging but the way Actions are rendered in HTTP using Link Headers has again little to do with the Link base type. Please see "Actions and the Link Header" at the end of [1] for a full description of this terminology confusion. - When the http://schemas.ogf.org/occi/core# was introduced I thought it a good idea to have it reserved for Categories defining the OCCI base types (i.e. Resource, Link, Action). Although not necessary I think keeping this distinction make the spec a bit easier to understand. The current definition of Categories is: The Category type represent the classification mechanism used by OCCI. It MUST be implemented. From a system point of view a Category is used for two different classification purposes. See also section 4.3 "Type System". 1. Taxonomy. A Category is used to assign static type information to each resource type inheriting Kind or a descendant of Kind. This use of Categories denotes the OCCI "static type system". A unique Category MUST be assigned to every descendant of Kind. See the section 4.1.2.1 "Hierarchy". 2. Folksonomy. A Category can be used to assign tags to resource instances via a mix-in like model. A Category mix-in MUST NOT be related to an OCCI base type (or any descendent of Kind) and MUST NOT be the unique identifier thereof. Example use cases are collections, location information and templates for virtual machine provisioning. Collections play nicely with 2, the "folksonomy" use of Categories. My point is that maybe we should have different schemes for Category use case 1 and 2, that is for Categories defined in Core. What do you think? It is not terribly important though. I.e. use a different scheme for the "tag" Category. I will annotate the wiki page as well. regards, Ralf [1] http://forge.ogf.org/sf/wiki/do/viewPage/projects.occi-wg/wiki/Link On Sun, 03 Oct 2010 17:16:57 +0200, Andy Edmonds <andy@edmonds.be> wrote:
Hey all, I've placed a write up of how categories and collections related to each other. Also there is how one can interact with collections. I've tried to keep the description as non-rendering-specific as possible.
http://forge.ogf.org/sf/wiki/do/viewPage/projects.occi-wg/wiki/Collections
If there are comments etc please annotate the wiki page at the appropriate place or place your questions in the "Open Issues" section.
Andy andy.edmonds.be