Hi - >From: Juergen Schoenwaelder <j.schoenwael...@jacobs-university.de> >Sent: Sep 14, 2015 11:41 PM >To: Ladislav Lhotka <lho...@nic.cz> >Cc: NETMOD Working Group <netmod@ietf.org> >Subject: Re: [netmod] Fwd: New Version Notification for >draft-ietf-netmod-yang-json-05.txt ... >My question is why the text is silent about the case where the data >model is present. Should it not say that if the data model is present, >the data encoded inside the anydata node must follow the rules of this >document? Perhaps this is the implicit assumption but I think it will >be useful to say this explicitly (if we agree on this). > >If the data model is not present, then I think an implementation is >still expected to produce an encoding that follows the rules of this >document as much as possible except that things that requires data >model knowledge may be encoded differently (e.g., numbers appearing as >strings or namespace names being different). I am thinking along the >lines of this proposed new text: > > An anydata data node can contain an unknown set of nodes that can > be modelled by YANG. A data model for anydata content may or may > not exist at run time. If the data model for anydata content is > available, then the anydata content MUST be encoded according to > the rules of this specification. If the data model for anydata > content is not available, the encoding MUST follow the rules of > this specification except for rules that require data model > knowledge (and as a consequence, numbers may appear as strings or > namespace qualifiers may not match module names).
This leaves me wondering what it means for the data model for anydata content to be "available". In the case of ASN.1's "ANY DEFINED BY" construct, there's an OBJECT IDENTIFIER to unambiguously identify the grammar (and associated semantics) to be used to understand the content, so tools can, if needed, scurry off to obtain the parsing instructions for those particular bits. How does an implementation know in the case of "anydata" which datamodel to use? Randy _______________________________________________ netmod mailing list netmod@ietf.org https://www.ietf.org/mailman/listinfo/netmod
