QDomDocument elementsByTagName and namespace

mrdebug

Hi I have to extrace the elments from a QDomDocument. The elements could have a node like
"s:Body"
or
"SOAP-ENV:Body
How can I extract the nodes searching "Body" without the namespace? Is there a way to have the namespace?

JonB

@mrdebug
Assuming you've checked that elementsByTagName() does not return namespaced-items. Then QDomNodeList QDomDocument::elementsByTagNameNS(const QString &nsURI, const QString &localName) can be used if you know which namespace(s) you want to search.

I'm not sure about a "get element by tag name across any namespace".

mrdebug

My problem in the implementation of onvif protocol.
A device responses with this document:

<SOAP-ENV:Body>
..

another device with

<s:Body>
..

so witch is the right way to have the "Body" element?

JonB

@mrdebug
I assume you will find that the response starts with a declaration of what namespaces it is using and what "aliases" (like s:) it is going to use? That's how it works in XML documents, I don't know anything about devices and what they might do.

Have you verified that elementsByTagName() does not return namespaced-items?

mrdebug

The function elementsByTagName() works with "SOAP-ENV:Body" and "s:Body". But the problem is that on my desk I have two devices that uses two different namespaces. My problem is to manage the response for all the devices. I think that could be other devices with other different namespaces.
Maybe the problem is the onvif / soap / xml protocol.
This is the full response

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENC="http://www.w3.org/2003/05/soap-encoding" xmlns:SOAP-ENV="http://www.w3.org/2003/05/soap-envelope" xmlns:chan="http://schemas.microsoft.com/ws/2005/02/duplex" xmlns:tdn="http://www.onvif.org/ver10/network/wsdl" xmlns:tds="http://www.onvif.org/ver10/device/wsdl" xmlns:tev="http://www.onvif.org/ver10/events/wsdl" xmlns:tptz="http://www.onvif.org/ver20/ptz/wsdl" xmlns:trt="http://www.onvif.org/ver10/media/wsdl" xmlns:tt="http://www.onvif.org/ver10/schema" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:wsa5="http://www.w3.org/2005/08/addressing" xmlns:wsdd="http://schemas.xmlsoap.org/ws/2005/04/discovery" xmlns:wsnt="http://docs.oasis-open.org/wsn/b-2" xmlns:wsrfbf="http://docs.oasis-open.org/wsrf/bf-2" xmlns:wsrfr="http://docs.oasis-open.org/wsrf/r-2" xmlns:wstop="http://docs.oasis-open.org/wsn/t-1" xmlns:xmime="http://tempuri.org/xmime.xsd" xmlns:xop="http://www.w3.org/2004/08/xop/include" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<SOAP-ENV:Header></SOAP-ENV:Header>
<SOAP-ENV:Body>
<tds:GetCapabilitiesResponse>
<tds:Capabilities>
<tt:Device>
<tt:XAddr>http://192.168.1.156:5000/onvif/device_service</tt:XAddr>
<tt:Network>
<tt:IPFilter>false</tt:IPFilter>
<tt:ZeroConfiguration>false</tt:ZeroConfiguration>
<tt:IPVersion6>false</tt:IPVersion6>
<tt:DynDNS>false</tt:DynDNS>
</tt:Network>
<tt:System>
<tt:DiscoveryResolve>false</tt:DiscoveryResolve>
<tt:DiscoveryBye>false</tt:DiscoveryBye>
<tt:RemoteDiscovery>true</tt:RemoteDiscovery>
<tt:SystemBackup>false</tt:SystemBackup>
<tt:SystemLogging>false</tt:SystemLogging>
<tt:FirmwareUpgrade>false</tt:FirmwareUpgrade>
<tt:SupportedVersions>
<tt:Major>2</tt:Major>
<tt:Minor>0</tt:Minor>
</tt:SupportedVersions>
<tt:Extension>
<tt:HttpFirmwareUpgrade>false</tt:HttpFirmwareUpgrade>
<tt:HttpSystemBackup>false</tt:HttpSystemBackup>
<tt:HttpSystemLogging>false</tt:HttpSystemLogging>
<tt:HttpSupportInformation>false</tt:HttpSupportInformation>
</tt:Extension>
</tt:System>
<tt:IO>
<tt:InputConnectors>2</tt:InputConnectors>
<tt:RelayOutputs>2</tt:RelayOutputs>
</tt:IO>
</tt:Device>
<tt:Media>
<tt:XAddr>http://192.168.1.156:5000/onvif/media_service</tt:XAddr>
<tt:StreamingCapabilities>
<tt:RTPMulticast>true</tt:RTPMulticast>
<tt:RTP_TCP>true</tt:RTP_TCP>
<tt:RTP_RTSP_TCP>true</tt:RTP_RTSP_TCP>
</tt:StreamingCapabilities>
</tt:Media>
<tt:PTZ>
<tt:XAddr>http://192.168.1.156:5000/onvif/ptz_service</tt:XAddr>
</tt:PTZ>
<tt:Extension>
<tt:DeviceIO>
<tt:XAddr>http://192.168.1.156:5000/onvif/deviceio_service</tt:XAddr>
<tt:VideoSources>1</tt:VideoSources>
<tt:VideoOutputs>0</tt:VideoOutputs>
<tt:AudioSources>0</tt:AudioSources>
<tt:AudioOutputs>0</tt:AudioOutputs>
<tt:RelayOutputs>0</tt:RelayOutputs>
</tt:DeviceIO>
</tt:Extension>
</tds:Capabilities>
</tds:GetCapabilitiesResponse>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>

JonB

@mrdebug said in QDomDocument elementsByTagName and namespace:

The function elementsByTagName() works with "SOAP-ENV:Body" and "s:Body".

Then in that case I don't follow your problem since you get BODY elements returned regardless of nname space, which seems to be what you want.

Anyway, if you want to find the namespaces used that is what the line

<SOAP-ENV:Envelope xmlns:SOAP-ENC="http://www.w3.org/2003/05/soap-encoding" xmlns:SOAP-ENV="http://www.w3.org/2003/05/soap-envelope" xmlns:chan="http://schemas.microsoft.com/ws/2005/02/duplex" xmlns:tdn="http://www.onvif.org/ver10/network/wsdl" ...

defines. If you look at the one which uses <s:Body> you'll see that has s: defined in same line.

Talkless

@JonB said in QDomDocument elementsByTagName and namespace:

you get BODY elements returned regardless of nname space,

NO, he explicitly said it works with explicit namespaces specifying SOAP-ENV:Body and s:Body, not just Body.

I have same issue with same ONVIF protocol supporting devices...

Alternative seems to use QXmlStreamReader, it's name() does return tag name without namespace, but you have to write much more imperative, manual code, comparing with QDomDocument.

kkoehne

@mrdebug , Qt 6.5 and onwards features new options for parsing, including the option QDomDocument::ParseOption::UseNamespaceProcessing . Have you tried this?

Talkless

@kkoehne said in QDomDocument elementsByTagName and namespace:

@mrdebug , Qt 6.5 and onwards features new options for parsing, including the option QDomDocument::ParseOption::UseNamespaceProcessing . Have you tried this?

Thanks, didn't knew that! We still use Qt 5.15 though...