Develop Reference

C# Using XPath with XmlDocument - Can't select nodes in a namespace (returning null)

I'm trying to do something which ought to be quite simple but I'm having terrible trouble. I have tried code from multiple similar questions in StackOverflow but to no avail.
I'm trying to get various pieces of information from an ABN lookup with the Australian government. Here is anonymised return XML value:
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Body>
<ABRSearchByABNResponse xmlns="http://abr.business.gov.au/ABRXMLSearch/">
<ABRPayloadSearchResults>
<request>
<identifierSearchRequest>
<authenticationGUID>00000000-0000-0000-0000-000000000000</authenticationGUID>
<identifierType>ABN</identifierType>
<identifierValue>00 000 000 000</identifierValue>
<history>N</history>
</identifierSearchRequest>
</request>
<response>
<usageStatement>The Registrar of the ABR monitors the quality of the information available on this website and updates the information regularly. However, neither the Registrar of the ABR nor the Commonwealth guarantee that the information available through this service (including search results) is accurate, up to date, complete or accept any liability arising from the use of or reliance upon this site.</usageStatement>
<dateRegisterLastUpdated>2017-01-01</dateRegisterLastUpdated>
<dateTimeRetrieved>2017-01-01T00:00:00.2016832+10:00</dateTimeRetrieved>
<businessEntity>
<recordLastUpdatedDate>2017-01-01</recordLastUpdatedDate>
<ABN>
<identifierValue>00000000000</identifierValue>
<isCurrentIndicator>Y</isCurrentIndicator>
<replacedFrom>0001-01-01</replacedFrom>
</ABN>
<entityStatus>
<entityStatusCode>Active</entityStatusCode>
<effectiveFrom>2017-01-01</effectiveFrom>
<effectiveTo>0001-01-01</effectiveTo>
</entityStatus>
<ASICNumber>000000000</ASICNumber>
<entityType>
<entityTypeCode>PRV</entityTypeCode>
<entityDescription>Australian Private Company</entityDescription>
</entityType>
<goodsAndServicesTax>
<effectiveFrom>2017-01-01</effectiveFrom>
<effectiveTo>0001-01-01</effectiveTo>
</goodsAndServicesTax>
<mainName>
<organisationName>COMPANY LTD</organisationName>
<effectiveFrom>2017-01-01</effectiveFrom>
</mainName>
<mainBusinessPhysicalAddress>
<stateCode>NSW</stateCode>
<postcode>0000</postcode>
<effectiveFrom>2017-01-01</effectiveFrom>
<effectiveTo>0001-01-01</effectiveTo>
</mainBusinessPhysicalAddress>
</businessEntity>
</response>
</ABRPayloadSearchResults>
</ABRSearchByABNResponse>
</soap:Body>
</soap:Envelope>
so I want to get for example the whole response using xpath="//response" then use various xpath statement within that node to get the <organisationName> ("//mainName/organisationName") and other values.
It should be simple right? Those xpath statements appear to work when testing in Notepad++but I use this code in Visual Studio:
XmlDocument xdoc = new XmlDocument();
xdoc.LoadXml(ipxml);
XmlNode xnode = xdoc.SelectSingleNode("//response");
XmlNodeList xlist = xdoc.SelectNodes("//mainName/organisationName");
xlist = xdoc.GetElementsByTagName("mainName");
But it always returns null, whatever I put in the xpath I get a null return for the node and 0 count for the list whether I'm selecting something with child nodes, a value or not.
I can get the nodes using GetElementsByTagName() as in the example which returns the correct node, but I wanted to do it 'properly' selecting the proper field using xpath.
I also tried using XElement and Linq but still no luck. Is there something weird about the XML?
I'm sure it must something simple but I've been struggling for ages.

You aren't dealing with the namespaces present in the document. Specifically, the high level element:
<ABRSearchByABNResponse xmlns="http://abr.business.gov.au/ABRXMLSearch/">
places ABRSearchByABNResponse, and all its child elements (unless overridden by another xmlns) into the namespace http://abr.business.gov.au/ABRXMLSearch/. In order to navigate to these nodes (without hacks like GetElementsByTagName or using local-name()), you'll need to register the namespaces with an XmlNamespaceManager, like so. The xmlns aliases don't necessarily need to match those used in the original document, but it's a good convention to do so:
XmlDocument
var xdoc = new XmlDocument();
var ns = new XmlNamespaceManager(xdoc.NameTable);
ns.AddNamespace("soap", "http://schemas.xmlsoap.org/soap/envelope/");
ns.AddNamespace("abr", "http://abr.business.gov.au/ABRXMLSearch/");
xdoc.LoadXml(ipxml);
// NB need to use the overload accepting a namespace
var xresponse = xdoc.SelectSingleNode("//abr:response", ns);
var xlist = xdoc.SelectNodes("//abr:mainName/abr:organisationName", ns);
XDocument
More recently, the powers of LINQ can be harnessed with XDocument, which makes working with namespaces much easier (Descendants finds child nodes at any depth)
var xdoc = XDocument.Parse(ipxml);
XNamespace soap = "http://schemas.xmlsoap.org/soap/envelope/";
XNamespace abr = "http://abr.business.gov.au/ABRXMLSearch/";
var xresponse = xdoc.Descendants(abr + "response");
var xlist = xdoc.Descendants(abr + "organisationName");
XDocument + XPath
You can also resort to using XPath in Linq to Xml, especially for more complicated expressions:
var xdoc = XDocument.Parse(ipxml);
var ns = new XmlNamespaceManager(new NameTable());
ns.AddNamespace("soap", "http://schemas.xmlsoap.org/soap/envelope/");
ns.AddNamespace("abr", "http://abr.business.gov.au/ABRXMLSearch/");
var xresponse = xdoc.XPathSelectElement("//abr:response", ns);
var xlist = xdoc.XPathSelectElement("//abr:mainName/abr:organisationName", ns);

You need to call SelectSingleNode and SelectNodes on the DocumentElement. You are calling them on the document itself.
For example:
XmlNode xnode = xdoc.DocumentElement.SelectSingleNode("//response");

in C# how to select specific Data from an XMLDocument?

i got below response through web request
<Shofar Target_="Base" >
<RapidOnSite_Pump Key="1" State="Idle" Amount="20" />
<RapidOnSite_Pump Key="2" State="Idle" Amount="15" />
<RapidOnSite_Pump Key="3" State="Despencing" Amount="25"/>
- <Verb_List>
<Verb_Item Key="1" Execute="RapidOnSite_Pump_AdHoc" Result="OK"
Detail="All Pumps►5" />
</Verb_List>
from this string i only want to select Nodes which State is not Idle.
My Code
string responseFromServer = MY_RESPONSE
XmlDocument mainxml = new XmlDocument();
mainxml.LoadXml(responseFromServer);
XmlNodeList xnList = mainxml .SelectNodes("/Shofar/RapidOnSite_Pump [#State!='Idle']");
But by this code i didnt get requirments. can anyone please help me?

In the chat you show real xml. It contains the namespace which must be taken into account!
mainxml.LoadXml(responseFromServer);
XmlNamespaceManager manager = new XmlNamespaceManager(mainxml.NameTable);
manager.AddNamespace("ns", "http://ShofarNexus.com");
XmlNodeList xnList = mainxml.SelectNodes("/ns:Shofar/ns:RapidOnSite_Pump [#State!='Idle']", manager);

You can use XElement to get your work done, unless you want to stick to XmlDocument.
XElement rootElem = XElement.Load(new StringReader(xmlStr));
var rapidOnSitePumpWhichAreNotIdle = rootElem.Descendants("RapidOnSite_Pump").Where(e => e.Attribute("State").Value != "Idle");
At the end you will get IEnumerable<XElement> which can be iterated over.

Selecting Particular Node List in XML

<Report xmlns="Microsoft.SystemCenter.DataWarehouse.Report.Alert" xmlns:p1="w3.org/2001/XMLSchema-instance"; Name="Microsoft.SystemCenter.DataWarehouse.Report.Alert" p1:schemaLocation="Microsoft.SystemCenter.DataWarehou?Schema=True">
<Title>Alert Report</Title>
<Created>6/27/2013 9:32 PM</Created>
<StartDate>6/1/2013 9:29 PM</StartDate>
<EndDate>6/27/2013 9:29 PM</EndDate>
<TimeZone>(UTC)</TimeZone>
<Severity>Warning, Critical</Severity>
<Priority>Low, Medium, High</Priority>
<AlertTable>
<Alerts>
<Alert>
<AlertName></AlertName>
<Priority></Priority>
</Alert>
</Alerts>
</AlertTable>
</Report>
So I'm trying to pull down the list of nodes that appear under Alerts child. So /Report/AlertTable/Alerts.
I've done very similar before but in this format it is not working for some reason. Can someone point me out in the right direction?
XmlDocument Log = new XmlDocument();
Log.Load("test.xml");
XmlNodeList myLog = Log.DocumentElement.SelectNodes("//Report/AlertTable/Alerts");
foreach (XmlNode alert in myLog)
{
Console.Write("HERE");
Console.WriteLine(alert.SelectNodes("AlertName").ToString());
Console.WriteLine(alert.SelectNodes("Priority").ToString());
Console.Read();
}
EDIT:
One of the responses had me try to use a bunch of namespace with p1 but had no such luck.
EDIT:
Did not work either:
var name = new XmlNamespaceManager(log.NameTable);
name.AddNamespace("Report", "http://www.w3.org/2001/XMLSchema-instance");
XmlNodeList xml = log.SelectNodes("//Report:Alerts", name);

From a site:
nodename Selects all nodes with the name "nodename"
/ Selects from the root node
// Selects nodes in the document from the current node that match the selection no matter where they are
So I believe
"/AlertTable/Alerts"
would work, as that would be 'from the root node' as well as
"Report/AlertTable/Alerts"
XPath Site

Figured this sucker out.
It had to do with the namespace of "Microsoft.SystemCenter.DataWarehouse.Report.Alert". Changing this to anything but that won't read the XML properly.
XmlDocument log = new XmlDocument();
log.Load(#"C:\Users\barranca\Desktop\test.xml");
// XmlNodeList xml = log.SelectNodes("//ns1:Alerts");
var name = new XmlNamespaceManager(log.NameTable);
name.AddNamespace("ns1", "Microsoft.SystemCenter.DataWarehouse.Report.Alert");
XmlNodeList xml = log.SelectNodes("//ns1:Alert", name);
foreach (XmlNode alert in xml)
{
Console.Write("HERE");
XmlNode test = alert.SelectSingleNode("//ns1:AlertName",name);
string testing = test.InnerText;
Console.Write(testing);
}

NodeList.SelectSingleNode() syntax

Having problems getting NodeList.SelectSingleNode() to work properly.
My XML looks like this:
<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?>
<inm:Results xmlns:inm="http://www.namespace.com/1.0">
<inm:Recordset setCount="18254">
<inm:Record setEntry="0">
<!-- snip -->
<inm:Image>fileName.jpg</inm:Image>
</inm:Record>
</inm:Recordset>
</inm:Results>
The data is a long series of <inm:Record> entries.
I open the doc and get create a NodeList object based on "inm:Record". This works great.
XmlDocument xdoc = new XmlDocument();
xdoc.Load(openFileDialog1.FileName);
XmlNodeList xRecord = xdoc.GetElementsByTagName("inm:Record");
I start looping through the NodeList using a for loop. Before I process a given entry, I want to check and see if the <inm:Image> is set. I thought it would be super easy just to do
string strImage = xRecord[i].SelectSingleNode("inm:Image").InnerText;
My thinking being, "For the XRecord that I'm on, go find the <inm:Image> value ...But this doesn't work as I get the exception saying that I need a XmlNameSpaceManager. So, I tried to set that up but could never get the syntax right.
Can someone show me how to use the correct XmlNameSpaceManager syntax in this case.
I've worked around the issue for now by looping through all of the childNodes for a given xRecord, and checking the tag once I loop around to it. I would like to check that value first to see if I need to loop over that <inm:Record> entry at all.

No need to loop through all the Record elements, just use XPath to specify the subset that you want:
XmlDocument xdoc = new XmlDocument();
xdoc.Load(openFileDialog1.FileName);
XmlNamespaceManager manager = new XmlNamespaceManager(xdoc.NameTable);
manager.AddNamespace("inm", "http://www.inmagic.com/webpublisher/query");
XmlNodeList nodes = xdoc.SelectNodes("/inm:Results/inm:Recordset/inm:Record[inm:Image != '']", manager);

Using the LINQ to XML libraries, here's an example for retrieving that said node's value:
XDocument doc = XDocument.Load(openFileDialog1.FileName);
List<XElement> docElements = doc.Elements().ToList();
XElement results = docElements.Elements().Where(
ele => ele.Name.LocalName == "Results").First();
XElement firstRecord = results.Elements().Where(
ele => ele.Name.LocalName == "Record").First();
XElement recordImage = firstRecord .Elements().Where(
ele => ele.Name.LocalName == "Image").First();
string imageName = recordImage.Value;
Also, by the way, using Hungarian notation for a type-checked language is overkill. You don't need to prepend string variables with str when it will always be a string.

XmlNamespaceManager nsMgr = new XmlNamespaceManager(xdoc.NameTable);
string strImage = xRecord[i].SelectSingleNode("inm:Image",nsMgr).InnerText;
Should do it.

Using this Xml library, you can get all the records that have an Image child element with this:
XElement root = XElement.Load(openFileDialog1.FileName);
XElement[] records = root.XPath("//Record[Image]").ToArray();
If you want to be sure that the Image child contains a value, it can be expressed like this:
XElement[] records = root.XPath("//Record[Image != '']").ToArray();

C# Xml Value always getting null

I have the following Xml in my Resources.xmltest:
<?xml version="1.0" encoding="utf-8" ?>
<Response xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://DFISofft.com/SmartPayments/">
<Result>0</Result>
<Message>Pending</Message>
<PNRef>222131</PNRef>
<ExtData>InvNum=123</ExtData>
</Response>
I've tried several ways to get the values, Result,Message,PNRef,ExtData, out of it and I've had no luck. I always get a null value for the NodePath so it never goes into the loop:
var XmlDoc = new XmlDocument();
XmlDoc.LoadXml(Resources.xmltest);
XmlElement NodePath = (XmlElement) XmlDoc.SelectSingleNode("/Response");
while (NodePath != null)
{
foreach (XmlNode Xml_Node in NodePath)
{
Console.WriteLine(Xml_Node.Name + " " + Xml_Node.InnerText);
}
}
I've tried this:
XmlNode node3 = XmlDoc.SelectSingleNode("PNRef");
Console.WriteLine(node3.Value);
Console.WriteLine(XmlDoc.InnerXml);
var tst = XmlDoc.GetElementsByTagName("PNRef");
Console.WriteLine(tst);
And this:
NodePath = (XmlElement) XmlDoc.SelectSingleNode("/Response");
if (NodePath != null)
{
foreach (XmlNode node in NodePath)
{
Console.WriteLine("NodeName: " + Xml_NodeX.Name);
Console.WriteLine("NodeValue: " + node.InnerText);
}
}
Apparently, I'm not getting the xml read/write. I've done it with DataSets but they do all the work for you.
Can someone point me in the right direction? I've been at this for longer than I should have been already.
Thank you!

Your XML has a XML namespace and you're not paying any attention to it:
<Response xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://DFISofft.com/SmartPayments/">
******************************************
When selecting from this XML, you need to use that XML namespace!
You're not taking into account the XML namespace (xmlns="http://nts-de-osm1-pxc/webservices/") on the document!
Try this:
var XmlDoc = new XmlDocument();
// setup the XML namespace manager
XmlNamespaceManager mgr = new XmlNamespaceManager(XmlDoc.NameTable);
// add the relevant namespaces to the XML namespace manager
mgr.AddNamespace("ns", "http://DFISofft.com/SmartPayments/");
XmlDoc.LoadXml(Resources.xmltest);
// **USE** the XML anemspace in your XPath !!
XmlElement NodePath = (XmlElement) XmlDoc.SelectSingleNode("/ns:Response");
while (NodePath != null)
{
foreach (XmlNode Xml_Node in NodePath)
{
Console.WriteLine(Xml_Node.Name + " " + Xml_Node.InnerText);
}
}

The problem is your XPath query, which doesn't specify a namespace - despite the fact that your document only has a Response element in the "http://DFISofft.com/SmartPayments/" namespace. Ditto the PNRef elements.
Personally I'd use LINQ to XML if I actually wanted to use namespaces if at all possible. For example:
XNamespace ns = "http://DFISofft.com/SmartPayments/";
XDocument doc = XDocument.Load(filename);
foreach (var element in doc.Descendants(ns + "PNRef"))
{
// Use element here
}
As you can see, LINQ to XML makes it really easy to use namespaces - but of course it requires .NET 3.5 or higher. If I had to use .NET 2.0, I'd either use XmlNamespaceManager or iterate manually and check local names instead of using XPath.

That is because the node isn't called response; you need to take the namespace into account:
var XmlDoc = new XmlDocument();
var nsmgr = new XmlNamespaceManager(XmlDoc.NameTable);
nsmgr.AddNamespace("x", "http://DFISofft.com/SmartPayments/");
XmlDoc.LoadXml(yourXml);
XmlElement NodePath = (XmlElement)XmlDoc.SelectSingleNode("/x:Response", nsmgr);

For future reference...
Bubba Soft
This site has a great free tool for building XPath Expressions (XPath Builder).

It's because you are using the overload of SelectSingleNode that assumes an empty namespace. Since you have a default namespace you will need to use the version that takes an XmlNamespaceManager. See this article for more info.
from the docs:
If the XPath expression does not include a prefix, it is assumed that the namespace URI is the empty namespace. If your XML includes a default namespace, you must still add a prefix and namespace URI to the XmlNamespaceManager; otherwise, you will not get a node selected. For more information, see Select Nodes Using XPath Navigation.