Re: Interaction model vs data model

* Arnaud Le Hors <> [2013-01-23 17:08-0800]
> There seems to be some confusion in the discussions as to what we can do 
> and what we can't which comes from different views of what LDP is about.
> Discussing whether LDPCs are a subclass of LDPRs, Henry wrote [1]: "they 
> are not, since POSTing a Graph on an LDPR is very different from POSTing 
> on an LDPC, and since RDF is a logical vocabulary that does not work with 
> the concept of method overloading. "
> I have to admit not to understand this statement at all and, maybe it's 
> just me but, I actually believe that clarifying this might help us a great 
> deal with the ongoing discussions around the interaction and data models.
> RDF doesn't have the concept of methods, so it certainly doesn't have the 
> concept of method overloading, but this merely concerns the data model. I 
> don't understand why this would prevent us from defining different ways of 
> handling HTTP verbs depending on the type of LDP resource we deal with - 
> an LDPR or LDPC. I would say this only concerns the interaction model and 
> the RDF data model doesn't prevent us from doing so.

I think that we are making only trivial statements about type if one
can't predict some opperational behavior from that type. The most
practical type I can imagine is one that tells me if POSTing RDF will
append it (LDPR) or submit a new element to a container (LDPC).  To
that end, I think that LDPC and LDPR are sibling resources with some
common ancestor. It's probably worth identifying that ancestor as it
has a few properties common to both LDPCs and LDPRs, namely that GET
gets you some relevant RDF and that it's defined by LDP.

> For what it's worth, section 5.2.1 of the LDP spec [2] states that "A 
> Linked Data Platform Container must also be a conformant Linked Data 
> Platform Resource." I've always read that as meaning that an LDPC is an 
> What am I missing?
> [1] 
> [2]
> --
> Arnaud  Le Hors - Software Standards Architect - IBM Software Group


Received on Thursday, 24 January 2013 04:36:31 UTC