[Nml-wg] xml list examples

[Jason Zurawski]

Hi All;

On 12/2/10 4:16 PM, Aaron Brown wrote:
> On the call, I was asked to send some examples of how we've done ordered lists in XML before. Looking through various xml bits, I found a few different ways that we've sorted lists.
>
> 1) a numerical 'id' element:
>
>           <nmwg-cp:hop id=”0”>
>               ....
>           </nmwg-cp:hop>
>           <nmwg-cp:hop id=”1”>
>               ....
>           </nmwg-cp:hop>
>           <nmwg-cp:hop id=”2”>
>               ....
>           </nmwg-cp:hop>
>           <nmwg-cp:hop id=”3”>
>               ....
>           </nmwg-cp:hop>
>
> 2) explicit 'next' pointers:
>
>        <path>
>            <hop id="internet2-1">
>                ....
>                <nextHop>esnet-1</nextHop>
>            </hop>
>            <hop id="esnet-1">
>                ....
>                <nextHop>bnl-1</nextHop>
>            </hop>
>            <hop id="bnl-1">
>                ....
>            </hop>
>        </path>


As discussed on the call one would need to have a parser that respected 
'document order' to ensure the next sequence is correct.  Modern XML 
parsers feature this (e.g. LibXML), but its not a part of the XML 
standard itself so there is no guarantee you will find it in all 
implementations.

Thanks;

-jason


> 3) implicit document ordering (this data corresponds to a traceroute. there would be more 'datum' elements in a real traceroute instance each of which corresponds to a single traceroute probe sent. This was cleaned up to make it easier to read):
>
>       <nmwg:data id="data.AAAFFF.0" metadataIdRef="meta.AAAFFF" xmlns:nmwg="http://ggf.org/ns/nmwg/base/2.0/">
>         <traceroute:datum hop="198.129.254.29" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="1" value="0.135" valueUnits="ms"/>
>         <traceroute:datum hop="134.55.219.10" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="2" value="1.14" valueUnits="ms"/>
>         <traceroute:datum hop="134.55.217.2" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="3" value="37.212" valueUnits="ms"/>
>         <traceroute:datum hop="134.55.209.98" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="4" value="1.616" valueUnits="ms"/>
>         <traceroute:datum hop="134.55.220.49" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="5" value="28.643" valueUnits="ms"/>
>         <traceroute:datum hop="134.55.209.46" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="6" value="41.773" valueUnits="ms"/>
>         <traceroute:datum hop="134.55.221.58" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="7" value="52.36" valueUnits="ms"/>
>         <traceroute:datum hop="134.55.218.101" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="8" value="52.373" valueUnits="ms"/>
>         <traceroute:datum hop="198.124.252.141" numBytes="64" queryNum="1" timeType="unix" timeValue="1282079154" ttl="9" value="52.311" valueUnits="ms"/>
>       </nmwg:data>
>
> Cheers,
> Aaron