Re: Shapes vs Classes (in LDOM)

Holger Knublauch <holger@topquadrant.com> wrote on 01/29/2015 06:55:33 PM:

> BTW wouldn't it have been better to use "oslc:shape" instead of 
> "oslc:instanceShape", because you don't really talk about "instances" 
> (of classes)?

Holger,

Historically, we first defined oslc:resourceShape as a way to link a shape 
with a service endpoint URI (essential a container) where you could create 
resources via POST or query them via GET.

However, we needed a way to support PUT operations. When a client GETs a 
resource it can look in it for an oslc:instanceShape triple. That tells 
the client how it can modify the resource and PUT it back to the server. 

The point is that if we just used one oslc:shape property then its meaning 
would be ambiguous in the RDF description of a service endpoint. A service 
endpoint description document needs to refer to its own shape as an RDF 
graph AND the shape of the RDF graphs that you, e.g., POST to it.

The term "instance" was used because in many cases the RDF graph does in 
fact represent some instance of an OO programming language object that 
lives in the server. We picked the term so that typical web application 
developers would understand it.

-- Arthur Ryman

Received on Thursday, 5 February 2015 20:32:15 UTC