[netconf] get-data origin filters

[Andy Bierman <[e-mail]>]

Hi,

I am trying to figure out how to use the origin-filter and
negated-origin-filter
in the <get-data> operation in RFC 8526.


          leaf-list origin-filter {
             type or:origin-ref;
             description
               "Filter based on the 'origin' annotation.  A
                configuration node matches the filter if its 'origin'
                annotation is derived from or equal to any of the given
                filter values.";
           }


These filters seem kind of worthless if implemented according to the text.
Consider a simple example where there is 1 learned leaf within a list:

module: address
  +--rw addresses
     +--rw address* [last-name first-name]
        +--rw last-name     string
        +--rw first-name    string
        +--rw street?       string
        +--rw city?         string
        +--rw zipcode?      string
        +--rw phone* [phone-type]
           +--rw phone-type      enumeration
           +--rw phone-number    string

Let's say the "zipcode" field is learned in <operational>
(e.g. ZIP code lookup expands missing or 5 digit zipcode to full 9 digit
zipcode).
So /addresses and /addresses/address have origin "intended".
Only the /addresses/address/zipcode leaf has origin "learned".

So how does origin-filter=learned find all the learned leafs?
What filters are required to return only the learned entries + ancestors +
ancestor-or-self keys?  Seems like this filter mechanism has to be used
to retrieve the exact leaf that might be learned, and the client
needs to know in advance all the possible nodes that might be learned.

Want to be able to retrieve an ancestor that is intended and still find the
learned entries

   get-data xpath-filter=/addresses/address origin-filtter=learned

The draft shows an example where both "intended" and "system" are given
as filters.  This will work but will include all the "intended" leafs as
well.
What if a "learned" node is within a "system" node within an "intended"
node?
Seems like the client needs to know a lot about the server implementation
details
in order to use the origin filters.


Andy