Re: [netmod] yang-instance-file include-defaults leaf

[Andy Bierman <[e-mail]>]

On Tue, Jul 13, 2021 at 8:07 AM Balázs Lengyel <[e-mail]>
wrote:

> Hello Andy,
>
> Looking through the use-cases I think the producer will always know
> whether it includes default values or not. This is the case if the instance
> data set is produced by the server e.g. in UC4, UC5,  or if it created by
> some design activity UC1, UC2, UC3, UC8. (UC6 and UC7 are so broad and
> loosely defined it is hard to say much about them.)
>
>
>
> Once the producer knows whether defaults are included or not it can set
> the include-defaults accordingly, so the default value for include-defaults
> is not so important. However, I chose trim as the default because:
>
>    - during the WGLC the draft explicitly stated that defaults SHOULD NOT
>    be included and the WG was happy/ok with that
>    - IMHO It is better to have short files,
>
>
>



I strongly object to having a default-stmt since it does matter and
the usage is incorrect.
If the include-defaults is not set then conveying a default value of 'trim'
is incorrect.
Leaving it out of a representation does not change the semantics of the
model.
The consumer will add that leaf = "trim" if it is missing.

Andy

Note, I used the term *producer*, as IMHO the above is true in all cases
> whether the server produces the file or some design activity creates the
> server.
>
> Regards Balazs
>
>
>
> *From:* netmod <[e-mail]> *On Behalf Of *Andy Bierman
> *Sent:* 2021. július 8., csütörtök 19:16
> *To:* NetMod WG <[e-mail]>
> *Subject:* [netmod] yang-instance-file include-defaults leaf
>
>
>
> Hi,
>
>
>
> The module has this object:
>
>
>
>     leaf includes-defaults {
>
>        type enumeration {
>
>          enum report-all {
>
>            value 1;
>
>            description
>
>              "All data nodes SHOULD be included independent of
>
>                any default values.";
>
>          }
>
>          enum trim {
>
>            value 2;
>
>            description
>
>              "Data nodes that have a default defined and where
>
>                the actual value is the default value SHOULD
>
>                NOT be included.";
>
>          }
>
>          enum explicit {
>
>            value 3;
>
>            description
>
>              "Data nodes that have a default defined and where
>
>                the actual value is the default value SHOULD NOT be
>
>                included. However, if the actual value was set by
>
>                a NETCONF client or other management application
>
>                by the way of an explicit management operation the
>
>                data node SHOULD be included.";
>
>          }
>
>        }
>
>        default trim;
>
>
>
> The draft is extremely server-centric, like most IETF standards, but this
>
> leaf is too server-centric to ignore.
>
>
>
> Consider the possibility that the source of the file is NOT a NETCONF
> server.
>
> This data may not be known so the default of "trim" may not be correct.
>
>
>
> IMO this leaf is noise because any tool that knows the schema will also
>
> know the YANG defaults.  The solution is incomplete anyway because
>
> the presence of a leaf that has a YANG default is not enough.
>
> The  "report-all-tagged" mode must be used to identify defaults.
>
> IMO this leaf should be removed, but at least add an enum called "unknown".
>
>
>
>
>
> Andy
>
>
>
>
>