Re: Proposal for containers

OK.  Here goes

Container Model

A. Containers can contain containers
Containers are LDPRs and should
be added to contianers like any other LDPR.

B. To add a container to a container, POST a (child) container
representation to a (parent) container.

C. Thus, a contianer can contain a mix of members and comtainers.
(Some of the members may be links to LDPRs.)

D. If you GET all members of a
container that has nested components, you get all the contents,
members and containers at the top level.  That is, you do not get nested
components.

Composition and Aggregation

E. If you delete a container you delete everything it contains.
For nested containers this leads to a cascaded delete.

F. If you do not want a member to be deleted when the container is deleted,
do not include the member in the containers but rather include a link to the
member in the container.

E and F follow the AtomPub model.  There are other proposals
-- distinct containers and aggregators, an attribute to distinguish
between containers and aggregators.  We can debate these separately
from A, B, C, D


All the best, Ashok

On 1/30/2013 4:06 AM, Steve Battle wrote:
> Thanks for the clarification Ashok.
>
> Given past confusion, I think it would be clearer if proposals about (container) composition and (RDF) aggregation were kept entirely separate.
> Is it possible to disentangle them?
>
> Steve.
>
> On 30 Jan 2013, at 00:50, Ashok Malhotra<ashok.malhotra@oracle.com>  wrote:
>
>> Steve:
>> My bad -- I used the word collection when I should have used container.
>>
>> It is about both composition and aggregation.  E and F address that.
>>
>> All the best, Ashok
>>
>> On 1/29/2013 7:25 PM, Steve Battle wrote:
>>> Ashok,
>>> I'm just seeking clarification here (no relevant issues are referenced in the subject line or body text).
>>>
>>> 1) Is this proposal about composition (the model), or aggregation?
>>> 2) Is a collection the same thing as a LDP container?
>>>
>>> Steve.
>>>
>>> On 29 Jan 2013, at 21:14, Ashok Malhotra<ashok.malhotra@oracle.com>   wrote:
>>>
>>>> I think we are converging, so I'm writing this up as a proposal for collection
>>>> handling.
>>>>
>>>> 3. Can collections contain collections?
>>>>
>>>> A. Yes, collections contain collections
>>>> Collections are LDPRs and should
>>>> be added to collections like any other LDPR.
>>>>
>>>> B. To add a collection to a collections, POST a (child) collection
>>>> representation to a (parent) collection.
>>>>
>>>> C. Thus, a collection can contain a mix of members and collections.
>>>> Some of the members may be links to LDPRs
>>>>
>>>> D. If you GET all members of a
>>>> collection that is nested, you get all the contents, members and collections
>>>> at the top level.  That is, you do not get nested members.
>>>>
>>>> E. If you delete a collection you delete everything it contains.  For nested collections
>>>> this leads to a cascaded delete.
>>>>
>>>> F. If you do not want a member to be deleted when the collection is deleted,
>>>> do not include the member in the collection but rather include a link to the
>>>> member in the collection.
>>>>
>>>> I realize that E and F are controversial.  If you disagree.  Please indicate which
>>>> parts of the proposal you disagree with.
>>>>
>>>> -- 
>>>> All the best, Ashok
>>>>
>

Received on Wednesday, 30 January 2013 15:23:59 UTC