[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: Re: [soa-rm-ra] Revised resource diagram
We do need identity, especially when we look at security. But even in other contexts, where something may have multiple identifiers. I don't see where I have implied that a resource is aware of its identity. My UML is not completely fluent either... Frank On Jan 18, 2008, at 10:41 AM, Duane Nickull wrote: > Frank: > > Your definitions seem to contradict. On one hand a resource "does > not know" > (which I inferred to mean it was a simple machine, chunk of bytes > etc.) and > on the other hand it is aware of its identity. Maybe I inferred > this wrong. > > I'll defer to Jeff, but unless a binary relationship attribute is > absolute > (true in 100% of all cases) I think it is best to be ambiguous (no > navigability). > > What about just having resources have identifiers? > > > Are these true: > A resource can have one of more identifiers. > An identifier is associated with one or more resources, but cannot > exist on > its own. > > > Do we even have to have identity? Identity is a test to me. You > inspect > "claims" made about a thing and either accept or reject them to > establish > identity. This is somewhat abstract and vague and can be done in > various > manners. > > Duane > > > On 1/18/08 10:25 AM, "Francis McCabe" <frankmccabe@mac.com> wrote: > >> Duane >> I think that, in principal, a stakeholder 'knows' what he/she owns! >> But, in general, it is normal for a stakeholder to know about owning >> things. On the other hand, that is not the case for a resource: it is >> not the normal case for a resource to be able to be aware of who owns >> it. >> When I looked to see what people defined identity as, the one that >> seemed closest was: >> Identity is the collection of individual characteristics by which a >> thing or person is recognized or known. >> >> This suggests identity is an aggregate. For us, we needed both the >> concept of identity and identifier in different parts of the >> architecture. Hence the inclusion. It is a slight specialization of >> this definition to focus on identifiers; doing it primarily because >> we >> needed to focus on the relationship between a resource, its identity >> and identifiers. Certainly, identifiers can and do exist >> independently >> of the things that they identify. >> >> AFAIK, roles in an association are simply another way of giving a >> name to the association -- it does not imply transitivity. >> >> In the diagram, the arrow goes from description to identifier, not >> the other way around. That implies (to me) that you can expect to >> navigate from descriptions to identifiers but not vice-versa. >> Similarly from identity to resource and from description to resource. >> >> The overall theme of navigability is that resources are the ultimate >> target of many associations; but that resources do not imply >> navigability back to their descriptions, identifiers, stakeholders >> etc. >> >> Frank >> >> On Jan 18, 2008, at 9:30 AM, Duane Nickull wrote: >> >>> Frank (Jeff - please read too). >>> >>> I think you should remove the traversibility indicators all >>> together. >>> >>> 1. Between Stakeholder and resource: >>> >>> They might (not in all cases) be aware of each other. Just a >>> straight line, >>> no arrows. >>> >>> 2. Between Resource and Identity and Identity - Identifier >>> >>> If you have labels at both ends (embodies, denoes) this implies a >>> binary >>> transitive relationship. Remove arrow. Also - if it is 1:1, I >>> think by >>> convention you might not have to explicitly note this. Regardless, >>> is there >>> any reason why a resource might not have two identities? I'd get >>> rid of the >>> cardinality indicators. >>> >>> I am not sure if we need both identity and identifier but might be >>> wrong. I >>> am also wanting to ask why an identity is aggregated from multiple >>> identifiers. Is it possible that the identifier exists without the >>> thing it >>> identifies? IMO - perhaps no. >>> >>> 3. Between Description and Identifier >>> >>> Are we implying that identifiers (which are items that act as >>> descriptors, >>> referencers) have a description themselves? Also - if the >>> description >>> references the identifier, you do not have to explicitly draw the >>> line >>> between the two as there is already an indirect connection via the >>> Description-Resource-Identity-Identifier path. >>> >>> CAVEAT: >>> >>> This is based on my understanding of UML. Jeff and others should >>> proof >>> this. >>> >>> Duane >>> >>> >>> On 1/17/08 10:49 AM, "Francis McCabe" <frankmccabe@mac.com> wrote: >>> >>>> This one has more cardinalities, and perhaps more careful >>>> navigation >>>> >>>> >>>> >>>> >>>> Frank >>>> --------------------------------------------------------------------- >>>> To unsubscribe from this mail list, you must leave the OASIS TC >>>> that >>>> generates this mail. You may a link to this group and all your TCs >>>> in OASIS >>>> at: >>>> https://www.oasis-open.org/apps/org/workgroup/portal/ >>>> my_workgroups.php >>> >>> -- >>> ********************************************************************** >>> "Speaking only for myself" >>> Senior Technical Evangelist - Adobe Systems, Inc. >>> Blog - http://technoracle.blogspot.com >>> Community Music - http://www.mix2r.com >>> My Band - http://www.myspace.com/22ndcentury >>> Adobe MAX 2008 - http://technoracle.blogspot.com/2007/08/adobe-max-2008.html >>> ********************************************************************** >>> >> > > -- > ********************************************************************** > "Speaking only for myself" > Senior Technical Evangelist - Adobe Systems, Inc. > Blog - http://technoracle.blogspot.com > Community Music - http://www.mix2r.com > My Band - http://www.myspace.com/22ndcentury > Adobe MAX 2008 - http://technoracle.blogspot.com/2007/08/adobe-max-2008.html > ********************************************************************** >
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]