Balázs Lengyel <balazs.leng...@ericsson.com> wrote:
> Hello,
>
> Recently we came up against a problem where a certain implementation
> did not accept the following:
>
> <with-defaults xmlns="...">
> report-all
> </with-defaults>
>
> while it did accept
>
> <with-defaults xmlns="...">report-all</with-defaults>
>
> I am unsure whether YANG's XML encoding allows whitespace before and
> after a leaf's value? In RFC7950 it does not say yes or no.
For example, RFC 7950 says about integers in 9.2.1:
An integer value is lexically represented as an optional sign ("+" or
"-"), followed by a sequence of decimal digits. If no sign is
specified, "+" is assumed.
So, space characters (and other characters) are not allowed. In XML,
whitespace has meaning, so:
<foo>42</foo>
is not the same as
<foo> 42 </foo>
Since the string " 42 " is not a legal integer lexical representation
according to 9.2.1, <foo> 42 </foo> is not a valid XML representation
for the integer foo.
> I have
> found the following examples that seem to allow preceding/following
> whitespace:
>
> https://tools.ietf.org/html/rfc7950#section-4.2.9
>
> <status xmlns="http://example.com/system";>
> The image example-fw-2.3 is being installed.
> </status>
>
> https://tools.ietf.org/html/rfc7950#section-7.16.3
>
> <reporting-entity>
> /ex:interface[ex:name='Ethernet0']
> </reporting-entity>
>
> https://tools.ietf.org/html/rfc6243#appendix-A.3.1
>
> <with-defaults
> xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults">
> report-all
> </with-defaults>
Yes, to be strict, these examples should have had some text that
explained that whitespace was added for readability. New documents
will hopefully use the new artwork draft's rules instead.
/martin
> It is problematic that this is not clarified. IMHO this should be
> clarified in an errata to rfc7950. Chose one:
>
> 1 It is not allowed to add preceding or following whitespace after the
> value of a leaf/leaf-list.
> Note that some text documents may add whitespace to Netconf examples
> to avoid long lines,
> however this extra whitespace MUST NOT be present in the actual
> Netconf encoding.
>
> 2 It is not allowed to add preceding or following whitespace after the
> value of a leaf/leaf-list.
> 3 It is allowed to add preceding or following whitespace after the
> value of a leaf/leaf-list except
> for string based types, where the whitespace could be part of the
> leaf's value itself..
>
> What do you think?
>
> regards Balazs
>
> --
> Balazs Lengyel Ericsson Hungary Ltd.
> Senior Specialist
> Mobile: +36-70-330-7909 email: balazs.leng...@ericsson.com
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