RE: [tosca] Propagation of default values in inheritance hierarchies: st

Yes, but this is not a âderivationâ scenario. Itâs just a simple âassignmentâ scenario.

Chris

From: Calin Curescu <calin.curescu@ericsson.com>
Sent: Tuesday, August 18, 2020 8:48 AM
To: Tal Liron <tliron@redhat.com>; Chris Lauwers <lauwers@ubicity.com>
Cc: Marton, Gabor (Nokia - HU/Budapest) <gabor.marton@nokia.com>; tosca@lists.oasis-open.org; Nemeth, Denes (Nokia - HU/Budapest) <denes.nemeth@nokia.com>; Nguyenphu, Thinh (Nokia - US/Dallas) <thinh.nguyenphu@nokia.com>
Subject: Re: [tosca] Propagation of default values in inheritance hierarchies: standpoint for TOSCA v1.2/v1.3?

Hi,

In TOSCA 2.0 these rules are stated in the section: 4.2.5.1 General derivation and refinement rules:

https://docs.oasis-open.org/tosca/TOSCA/v2.0/csd02/TOSCA-v2.0-csd02.html#_Toc44418531

BR/C

From: <tosca@lists.oasis-open.org> on behalf of Tal Liron <tliron@redhat.com>
Date: Monday, 17 August 2020 at 00:09
To: Chris Lauwers <lauwers@ubicity.com>
Cc: "Marton, Gabor (Nokia - HU/Budapest)" <gabor.marton@nokia.com>, "tosca@lists.oasis-open.org" <tosca@lists.oasis-open.org>, "Nemeth, Denes (Nokia - HU/Budapest)" <denes.nemeth@nokia.com>, "Nguyenphu, Thinh (Nokia - US/Dallas)" <thinh.nguyenphu@nokia.com>
Subject: Re: [tosca] Propagation of default values in inheritance hierarchies: standpoint for TOSCA v1.2/v1.3?

Well, not quite an inheritance issue but a "propagation" issue. I guess the question is whether by encapsulating one data type inside another the default properties would also be included. I'm sure we all agree that the answer is yes.

It's not immediately obvious, so I would recommend adding an explanation in the spec, possibly with an example.

On Sun, Aug 16, 2020 at 4:08 PM Chris Lauwers <lauwers@ubicity.com> wrote:

Iâm not sure there is a âpropagationâ (or inheritance) issue here. This seems to be a very straightforward example where (as Gabor states) the resulting value is indeed 1.

Chris

From: tosca@lists.oasis-open.org <tosca@lists.oasis-open.org> On Behalf Of Tal Liron
Sent: Saturday, August 15, 2020 12:44 PM
To: Marton, Gabor (Nokia - HU/Budapest) <gabor.marton@nokia.com>
Cc: tosca@lists.oasis-open.org; Nemeth, Denes (Nokia - HU/Budapest) <denes.nemeth@nokia.com>; Nguyenphu, Thinh (Nokia - US/Dallas) <thinh.nguyenphu@nokia.com>
Subject: Re: [tosca] Propagation of default values in inheritance hierarchies: standpoint for TOSCA v1.2/v1.3?

As you point out, the spec wasn't entirely clear up to 1.3. I think somewhere it does point out that all keywords are inherited, but I can't find it right now...

In any case, I think all popular current implementations inherit the "default" keyword, as it does seem to be natural and intended.

On Fri, Aug 14, 2020 at 1:30 PM Marton, Gabor (Nokia - HU/Budapest) <gabor.marton@nokia.com> wrote:

Dear TOSCA Experts,

in TOSCA v1.2 and v1.3, is the below example node template valid i.e. does its (required) property complex_1.example_1.property_1 have the value value_1?

data_types:

provider.datatypes.Example:

    derived_from: tosca.datatypes.Root

    properties:

      property_1:

        type: string

        default: value_1

provider.datatypes.Complex:

    derived_from: tosca.datatypes.Root

    properties:

      example_1:

        type: provider.datatypes.Example

node_types:

provider.nodes.Example:

    derived_from: tosca.nodes.Root

    properties:

      complex_1:

        type: provider.datatypes.Complex

topology_template:

node_templates:

    example:

      type: provider.nodes.Example

Propagation of default values is not explicitly covered by TOSCA v1.2/v1.3.

In the TOSCA v2.0 draft, I can see one sentence that makes me answer the above question affirmatively: âdefault: a new definition is unrestricted and will overwrite the one inherited from the property definition in the parent entity type definition" (4.4.5.5 Refinement rules).

Greetings,

GÃbor

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