[SR-Users] XMLOPS xpath issues

[Daniel-Constantin Mierla]

On 2/27/12 9:28 PM, Olle E. Johansson wrote:
> 27 feb 2012 kl. 21:07 skrev Daniel-Constantin Mierla:
>
>> Hello,
>>
>> an xpath invalid expression should be printed when the xpath expression is incorrect -- I cannot say what is wrong, not being an xpath expert by hart.
>>
>> However, there is a mismatching between the xml standards and SIP/SIMPLE specs. In XML, the namespaces are bound to prefixes, while the guys at IETF added by their own so called default namespace, which has no prefix for it. That results in not being able to use directly xpath from libxml2 with SIMPLE bodies.
>>
>> There were some discussions out there (you can google, iirc Inaki was in couple of them), in one side, the devs of libxml2 said they don't want to break XML standards by allowing bogus xpath queries with such namespaces. The workaround is to define xmlns prefix in xmlops module:
>>
>> http://kamailio.org/docs/modules/devel/modules/xmlops.html#xml_ns
>>
>> modparam("xmlops", "xml_ns", "ri=urn:ietf:params:xml:ns:reginfo")
>>
>> and try:
>>
>> $xml(pub=>xpath://ri:reginfo/ri:registration@aor)
> Thanks!
>
> The weird part is that I after adding that modparam get this error message:
> loading modules under /usr/local/lib64/kamailio/modules_k/:/usr/local/lib64/kamailio/modules/
>   0(65556) ERROR:<core>  [modparam.c:162]: set_mod_param_regex: No module matching<xmlops>  found
>   0(65556) :<core>  [cfg.y:3504]: parse error in config file kam-modules.inc, line 86, column 65: Can't set module parameter
>
> This is on FreeBSD.
>
> If I raise the debug I see the module being loaded and that it registers PVs
>
>   0(63596) DEBUG:<core>  [mem/q_malloc.c:369]: qm_malloc(0x800c00000, 40) called from xmlops: pv_xml.c: pv_parse_xml_name(448)
>
> Weird stuff.
>
> Kamailio 3.2.2
there was a wrong internal module name, initially I added the xml 
manipulation function as part of presence_xml, but then spit them out 
and made a dedicated one. But the name was not updated. The patch is now 
in 3.2 branch:

http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=3259ef734158d9cd63ce3fa94565f5cd4260e3f6

If you cannot update right now, try:

modparam("presence_xml", "xml_ns", "ri=urn:ietf:params:xml:ns:reginfo")

Not sure if it works if presence_xml is loaded, but if not, it should.

Cheers,
Daniel

-- 
Daniel-Constantin Mierla -- http://www.asipto.com
http://linkedin.com/in/miconda -- http://twitter.com/miconda