Yes, we're on the same page, I just used the opportunity to clarify how ARIA implements this variance.
On Thu, Nov 16, 2017 at 6:30 PM, DeWayne Filppi <dewa...@cloudify.co> wrote: > I meant attribute values differ. Property values don't differ between > instances. When I mean allow functions to be values, I mean the return > value only from the TOSCA perspective. > > On Thu, Nov 16, 2017 at 3:21 PM, Tal Liron <t...@cloudify.co> wrote: > > > Well, you can argue that attributes *vary* per node instance, while > > properties *do not vary* per node instance. > > > > Our discussion about function values is important: if a property value > is a > > function, the actual evaluated value might indeed be different per node > > instance. > > > > ARIA actually does keep copies of everything (both properties and > > attributes) for every node instance in the models. We made this blanket > > decision to allow for full flexibility in implementing plugins and > > supporting future versions of TOSCA. While in TOSCA properties are > strictly > > read-only at the parser level, it may be possible for plugins to change > > property values. Imagine, for example, a plugin that takes existing > Compute > > nodes and upgrades them: many of their properties may change. > > > > It's fine and good for TOSCA to be strict, but we wanted ARIA to > underneath > > be as flexible as needed. > > > > On Thu, Nov 16, 2017 at 5:12 PM, DeWayne Filppi <dewa...@cloudify.co> > > wrote: > > > > > Properties and attributes have no relationship. I always assumed the > > > reflection was a convenience. Attributes are per instance, not per > node. > > > > > > On Thu, Nov 16, 2017 at 2:54 PM, Tal Liron <t...@cloudify.co> wrote: > > > > > > > The reason I think this is a bad feature is that TOSCA makes such a > > clear > > > > effort to separate properties from attributes, but then this > reflection > > > > features means that basically it's enough to only have properties... > > > > > > > > My proposal for TOSCA 2.0 would be to have *just* properties and to > > allow > > > > some properties to have "mutable: true" if you want then to behave > like > > > an > > > > attribute. > > > > > > > > On Thu, Nov 16, 2017 at 3:01 PM, Steve Baillargeon < > > > > steve.baillarg...@ericsson.com> wrote: > > > > > > > > > Hi Tal > > > > > I found the magic statement in 3.5.8.1.1 > > > > > Yes the reflected attribute name must be the same as the property > > name > > > > for > > > > > the reflection feature. > > > > > Now I understand your second point. Thanks for your patience. > > > > > > > > > > Why do you think it is a bad feature? > > > > > Property is the desired value while reflected attribute is the > actual > > > > > value. > > > > > It seems logical to show actual value. > > > > > Or are you saying the actual value will always be the same as the > > > desired > > > > > value and the reflected attribute is useless? > > > > > > > > > > -Steve > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > From: Tal Liron [mailto:t...@cloudify.co] > > > > > Sent: Thursday, November 16, 2017 3:49 PM > > > > > To: dev@ariatosca.incubator.apache.org > > > > > Subject: Re: Attribute and Property Reflection > > > > > > > > > > The reflection feature is mentioned very, very briefly in just that > > one > > > > > sentence in the spec. They is no mention of changing names, so I am > > > > > expecting that the attribute names would be identical to the > property > > > > > names. In that case, there would be a conflict if an attribute has > > the > > > > same > > > > > name as a property -- otherwise how would the property be > reflected? > > > > That's > > > > > why I'm assuming that for this to work we should not allow an > > attribute > > > > > name to override a property name. > > > > > > > > > > My preferred solution is not to add any custom prefixes in ARIA, > > > because > > > > > they would not be portable > > > > > > > > > > The TOSCA spec has many authors, and it would be hard to track down > > the > > > > > particular one who wrote this sentence... Personally, I think this > is > > > an > > > > > awful and unclear feature. > > > > > > > > > > On Thu, Nov 16, 2017 at 2:43 PM, Steve Baillargeon < > > > > > steve.baillarg...@ericsson.com> wrote: > > > > > > > > > > > Back 1 step please. > > > > > > Are you saying that attribute names and property names within a > > Type > > > > > > MUST be different? > > > > > > As far as I know they can be the same e.g. <attribute_name_1> = > > > > > > <property_name 1> > > > > > > > > > > > > attributes: > > > > > > <attribute_name_1>: > > > > > > type:string > > > > > > properties: > > > > > > <property_name 1>: > > > > > > type:string > > > > > > > > > > > > > > > > > > Back to reflection. > > > > > > I am proposing <attribute_name> = actual_<property_name> But I > > think > > > > > > it is best if I ask further clarification from YAML Profile > > authors. > > > > > > What do you think? > > > > > > What is your preferred solution? > > > > > > > > > > > > -Steve > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > From: Tal Liron [mailto:t...@cloudify.co] > > > > > > Sent: Thursday, November 16, 2017 3:15 PM > > > > > > To: dev@ariatosca.incubator.apache.org > > > > > > Subject: Re: Attribute and Property Reflection > > > > > > > > > > > > Steve, we cannot change the TOSCA spec, and the spec does not say > > > > > > anything about naming conventions here. > > > > > > > > > > > > I think, though, that an obvious part of this JIRA will be to > emit > > an > > > > > > error if an attribute name is the same as a property name, > because > > > > > > obviously this would break this feature. > > > > > > > > > > > > On Thu, Nov 16, 2017 at 2:12 PM, Steve Baillargeon < > > > > > > steve.baillarg...@ericsson.com> wrote: > > > > > > > > > > > > > I see the following text in the JIRA: > > > > > > > According to the TOSCA 1.0 spec, property value should be > > > 'exposed', > > > > > > > with the same name, as attributes. > > > > > > > > > > > > > > Does the spec really say to use the same name? As far as I know > > it > > > > > > > does not. > > > > > > > What about using a better reflected attribute naming convention > > > like > > > > > > > “actual_<property_name>”? > > > > > > > Can I add this to the JIRA? > > > > > > > > > > > > > > -Steve B > > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: Tal Liron [mailto:t...@cloudify.co] > > > > > > > Sent: Thursday, November 16, 2017 2:48 PM > > > > > > > To: dev@ariatosca.incubator.apache.org > > > > > > > Subject: Re: Attribute and Property Reflection > > > > > > > > > > > > > > Not right now, but there is an open JIRA to support it. > > > > > > > > > > > > > > On Thu, Nov 16, 2017 at 1:42 PM, Steve Baillargeon < > > > > > > > steve.baillarg...@ericsson.com> wrote: > > > > > > > > > > > > > > > Hi > > > > > > > > Does ARIA support "attribute and property reflection" defined > > in > > > > > > > 3.5.10.1? > > > > > > > > > > > > > > > > Regards > > > > > > > > Steve B > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
