XML, XPath and namespaces

[NeilA]

I have gotten used to the awkwardness of XML in LabVIEW but have just come up against a massive problem of using XPath and trying to parse namespaced xml. Basically where XPath used to do the trick it now doesnt because parts of my xml are in a different namespaces. I cant figure out how to get acces to the namespace manager or anything (which is what you need to do according to google). I need to talk to my colleague who has just added the namespaces and made my day very hard, but, I may just remove them for my simple implementation if there is no way round it in LabVIEW.

I have attached an example XML where I used to be able to loadXML String and then SelectSingleNode with an XPath of /soap:Envelope/soap:Header/UUID/UUID to get the guid.

Any ideas on what to use? I have had a look round in the constructors but cant work out how to do this, is it me or does this just seem like even more hard work, blooming XML :headbang:

Many Thanks in advance..

<?xml version="1.0" encoding="utf-8"?>

<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">

<soap:Header>

<UUID xmlns="http://RMS/">

<UUID>guid</UUID>

</UUID>

</soap:Header>

<soap:Body>

<ControlResume xmlns="http://RMS/">

<ParameterList>

<Parameter>

<Type>string</Type>

<Name>string</Name>

<Value>

<string>string</string>

<string>string</string>

</Value>

<Units>string</Units>

</Parameter>

<Parameter>

<Type>string</Type>

<Name>string</Name>

<Value>

<string>string</string>

<string>string</string>

</Value>

<Units>string</Units>

</Parameter>

</ParameterList>

</ControlResume>

</soap:Body>

</soap:Envelope>

[mje]

QUOTE (NeilA @ Apr 6 2009, 02:14 PM)

I have attached an example XML where I used to be able to loadXML String and then SelectSingleNode with an XPath of /soap:Envelope/soap:Header/UUID/UUID to get the guid.

...

<UUID xmlns="http://RMS/">

That path isn't correct, your XML puts the parent UUID element within the http://RMS/ namespace.

[NeilA]

QUOTE (MJE @ Apr 6 2009, 07:24 PM)

That path isn't correct, your XML puts the parent UUID element within the http://RMS/ namespace.

Sorry to be an idiot but could you please explain further? I have tried using different namespaces and xpath combinations but cant get any further, are you suggesting that I still use SelectSingleNode method of the xpath class but with a different xpath!?!

Thanks

[Matthew Zaleski]

QUOTE (NeilA @ Apr 6 2009, 03:43 PM)

Sorry to be an idiot but could you please explain further? I have tried using different namespaces and xpath combinations but cant get any further, are you suggesting that I still use SelectSingleNode method of the xpath class but with a different xpath!?!

Thanks

Welcome to the world of XML.

What MJE is telling you is that you did a deliberate override of the namespace for the UUID element (you gave it the namespace "http://RMS/"). Therefore /soap:Envelope/soap:Header/UUID/UUID will fail at the first UUID element since it isn't in the default namespace within the XML. I'm not familiar with the namespace "http://RMS/". Did you make that up?

If so, modify your XML header:

<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:rms="http://RMS/"> and add that rms: prefix to your UUID element in XML file.

Then the following XPath will be valid:

/soap:Envelope/soap:Header/rms:UUID

[NeilA]

QUOTE (Matthew Zaleski @ Apr 6 2009, 09:23 PM)

Welcome to the world of XML.

Yeah Thanks,

I have been happily using XPath without any issues but the addition of namespaces has seemed to just add headaches. I dont have control of the namespaces this XML is the soap message sent to me from another system.

I have been playing around with the LabVIEW XML parser property and invoke nodes as they contain a function to ignore the namespaces but the LabVIEW implementation is based around DOM and I find it really cumbersome after XPath plus I dont really want to re-write everything.

Is there any way I can access the namespaces myself (ie namespace manager/nametable (bear in mind I got this info from the net I have only just heard about them and I dont know if I am asking the correct thing lol!))to recover the XPath solutions I have already implemented.

Thanks for the help so far.

Neil.

Sorry, Not to worry chatted to my colleague doing my other system. I am pretty certain that I will always be using the RMS namespace etc. So to make it easier I have the incoming message pass through a vi that removes all the namespace stuff and makes it work again in XPath.

Thanks for all your help though.