Hi Bart,

Alas, it sounds like you are attempting to do exactly what the existing text is attempting to prevent you from doing. In particular, your approach will break an existing client from working that hasn't been coded to be aware of the new augment-base module.

In terms of your solution, unless I'm missing something, then I'm not sure whether the deviation really helps - it seems to be equivalent to be just writing the must statement directly on 'leaf d' in the augment-base module

IIRC, I don't think that YANG prevents you from using a "must" statement to effectively make a leaf mandatory. However, even if this is allowed, it is probably against the spirit of the constraint that YANG is attempting to impose here. I.e. specifically that changes/augmentations to YANG modules are expected to be fully backwards compatible.

Thanks,
Rob


On 28/11/2016 15:01, Bogaert, Bart (Nokia - BE) wrote:
What we want to express is that if the NC client sends a request to
configure an object of class base we have a means to express that it also
has to send a value for the augmented leaf.  The reason why it is in an
augment is because we can't modify the base class.

Best regards - Vriendelijke groeten,
Bart Bogaert
Broadband-Access System Architect Data
Contact number +32 3 2408310 (+32 477 673952)

NOKIA
Copernicuslaan 50, 2018 Antwerp, Belgium
Fortis 220-0002334-42
VAT BE 0404 621 642 Register of Legal Entities Antwerp

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This message (including any attachments) contains confidential information
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-----Original Message-----
From: Martin Bjorklund [mailto:[email protected]]
Sent: 28 November 2016 14:45
To: Bogaert, Bart (Nokia - BE) <[email protected]>
Cc: [email protected]; [email protected]
Subject: Re: [netmod] Mandatory leafs via augment

"Bogaert, Bart (Nokia - BE)" <[email protected]> wrote:
Hi Rob,

In the case we're trying to work out basically client and server would
be aware of base class, augmentation and deviation as the SW running
on the box is expecting a value for a leaf of the augmented data, so
leaf d for the NC server (and the application SW dealing with the HW)
is expected to have a value in the device.  The device would not
support objects of the base class only.  I could understand that a NC
client interacts with other servers only supporting the base class as
that device may not require the augmented leafs.
I don't understand what you want to do.  It seems as if you're saying that
if the client thinks that leaf d is mandatory then leaf d is mandatory.
Otherwise leaf d is not mandatory.


/martin


Best regards - Vriendelijke groeten,

Bart Bogaert

Broadband-Access System Architect Data

Contact number +32 3 2408310 (+32 477 673952)

NOKIA

Copernicuslaan 50, 2018 Antwerp, Belgium Fortis 220-0002334-42 VAT BE
0404 621 642 Register of Legal Entities Antwerp



<<
This message (including any attachments) contains confidential
information intended for a specific individual and purpose, and is
protected by law. If you are not the intended recipient, you should
delete this message. Any disclosure, copying, or distribution of this
message, or the taking of any action based on it, is strictly
prohibited without the prior consent of its author.
From: Robert Wilton [mailto:[email protected]]
Sent: 28 November 2016 12:48
To: Bogaert, Bart (Nokia - BE) <[email protected]>
Cc: [email protected]
Subject: Re: [netmod] Mandatory leafs via augment

Hi Bart,

In your idea, am I correct to assume that only the client loads
(base-class, augment-base, and base-deviation), and the server only
knows about (base-class and augment-base)?

Further, am I right to assume that the server would still support
clients configuring base even if they don't know about augment-base?
I.e. from a server perspective, leaf d isn't actually mandatory.

Thanks,
Rob



On 28/11/2016 11:28, Bogaert, Bart (Nokia - BE) wrote:

Assume the following.
module base-class {
    prefix base;
    container base {
       leaf a;
       leaf b;
       leaf c;
    }
}
module augment-base {
   prefix aug;
   import base-class { prefix base; }
augment '/base:base'{
     leaf d;
   }
}
module base-deviation {
   prefix base-dev;
deviation "/base:base" {
     deviate add {
       must "./aug:d" {
         error-message "A value for d must be present when configuring
augmented base";
       }
     }
   }
Best regards - Vriendelijke groeten,
Bart Bogaert
Broadband-Access System Architect Data Contact number +32 3 2408310
(+32 477 673952)
NOKIA
Copernicuslaan 50, 2018 Antwerp, Belgium Fortis 220-0002334-42 VAT BE
0404 621 642 Register of Legal Entities Antwerp
<<
This message (including any attachments) contains confidential
information intended for a specific individual and purpose, and is
protected by law. If you are not the intended recipient, you should
delete this message. Any disclosure, copying, or distribution of this
message, or the taking of any action based on it, is strictly
prohibited without the prior consent of its author.

-----Original Message-----
From: Juergen Schoenwaelder
[mailto:[email protected]]
Sent: 28 November 2016 12:09
To: Bogaert, Bart (Nokia - BE)  <mailto:[email protected]>
<[email protected]>
Cc: [email protected] <mailto:[email protected]>
Subject: Re: [netmod] Mandatory leafs via augment
On Mon, Nov 28, 2016 at 10:42:42AM +0000, Bogaert, Bart (Nokia - BE)
wrote:
How can we achieve the same if no when-clause can be constructed but
we still would like to have a leaf to be mandatory.  One way we
thought of achieving this is
- have a YANG module defining the augmented data - construct a must statement on the object being augmented where

we

check that something needs to be present that is added via a deviation.
An example may help here... /js





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