Develop Reference

Accessing the xml tag with C# and updating the content

I have an xml file that I converted from pdf to xml.
Example XML looks as follows
<?xml version="1.0" encoding="UTF-8"?>
<office:document xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0" xmlns:style="urn:oasis:names:tc:opendocument:xmlns:style:1.0" xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0" xmlns:table="urn:oasis:names:tc:opendocument:xmlns:table:1.0" xmlns:draw="urn:oasis:names:tc:opendocument:xmlns:drawing:1.0" xmlns:fo="urn:oasis:names:tc:opendocument:xmlns:xsl-fo-compatible:1.0" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:meta="urn:oasis:names:tc:opendocument:xmlns:meta:1.0" xmlns:number="urn:oasis:names:tc:opendocument:xmlns:datastyle:1.0" xmlns:presentation="urn:oasis:names:tc:opendocument:xmlns:presentation:1.0" xmlns:svg="urn:oasis:names:tc:opendocument:xmlns:svg-compatible:1.0" xmlns:chart="urn:oasis:names:tc:opendocument:xmlns:chart:1.0" xmlns:dr3d="urn:oasis:names:tc:opendocument:xmlns:dr3d:1.0" xmlns:math="http://www.w3.org/1998/Math/MathML" xmlns:form="urn:oasis:names:tc:opendocument:xmlns:form:1.0" xmlns:script="urn:oasis:names:tc:opendocument:xmlns:script:1.0" xmlns:config="urn:oasis:names:tc:opendocument:xmlns:config:1.0" xmlns:ooo="http://openoffice.org/2004/office" xmlns:ooow="http://openoffice.org/2004/writer" xmlns:oooc="http://openoffice.org/2004/calc" xmlns:dom="http://www.w3.org/2001/xml-events" xmlns:xforms="http://www.w3.org/2002/xforms" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:smil="urn:oasis:names:tc:opendocument:xmlns:smil-compatible:1.0" xmlns:anim="urn:oasis:names:tc:opendocument:xmlns:animation:1.0" xmlns:rpt="http://openoffice.org/2005/report" xmlns:of="urn:oasis:names:tc:opendocument:xmlns:of:1.2" xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:grddl="http://www.w3.org/2003/g/data-view#" xmlns:officeooo="http://openoffice.org/2009/office" xmlns:tableooo="http://openoffice.org/2009/table" xmlns:drawooo="http://openoffice.org/2010/draw" xmlns:calcext="urn:org:documentfoundation:names:experimental:calc:xmlns:calcext:1.0" xmlns:loext="urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0" xmlns:field="urn:openoffice:names:experimental:ooo-ms-interop:xmlns:field:1.0" xmlns:formx="urn:openoffice:names:experimental:ooxml-odf-interop:xmlns:form:1.0" xmlns:css3t="http://www.w3.org/TR/css3-text/" office:version="1.2" office:mimetype="application/vnd.oasis.opendocument.graphics">
<office:body>
<office:drawing>
<draw:page draw:name="page1" draw:style-name="dp2" draw:master-page-name="master-page3">
<draw:frame draw:style-name="gr9" draw:text-style-name="P10" draw:layer="layout" svg:width="1.242cm" svg:height="0.357cm" svg:x="17.055cm" svg:y="11.787cm">
<draw:text-box>
<text:p text:style-name="P2"><text:span text:style-name="T6">Example</text:span></text:p>
</draw:text-box>
</draw:frame>
</draw:page>
</office:drawing>
</office:body>
</office:document>
The C# code I'm trying to use:
XmlDocument doc = new XmlDocument();
XmlNamespaceManager namespaces = new XmlNamespaceManager(doc.NameTable);
namespaces.AddNamespace("xmlns:draw", "urn:oasis:names:tc:opendocument:xmlns:drawing:1.0");
doc.Load("invoiceto.xml");
doc.SelectSingleNode("/draw:frame/draw:text-box/text:p/text:span", namespaces).InnerText = "new value";
I get this error
'' text 'namespace prefix not defined.'
I want to replace the text of example with C# but how can I get to the <text: span text: style-name = "T6"> tag with C#?

First of all the prefix added to XmlNamespaceManager shouldn't include the xmlns part. Then you also need to add the prefix text besides draw because both will be used in the XPath expression for calling SelectSingleNode. Last, since the element <draw:frame> isn't the root element you need to either specify full path starting from the root or start the XPath using // (the descendant-or-self axis) instead:
XmlNamespaceManager namespaces = new XmlNamespaceManager(doc.NameTable);
namespaces.AddNamespace("draw", "urn:oasis:names:tc:opendocument:xmlns:drawing:1.0");
namespaces.AddNamespace("text", "urn:oasis:names:tc:opendocument:xmlns:text:1.0");
doc.SelectSingleNode("//draw:frame/draw:text-box/text:p/text:span", namespaces).InnerText = "new value";
dotnetfiddle demo

Adding child node inside a XML node using C#

Here is my given XML:-
<?xml version="1.0" encoding="utf-8"?>
<Processes>
<Process Name="Process1" Namespace="" Methodname="">
<Validations/>
<Transformations/>
<Routings/>
</Process>
</Processes>
I want to add new node Validation inside Validations and for that i have written the following code:-
XmlDocument originalXml = new XmlDocument();
originalXml.Load(#"C:\Users\Sid\Desktop\Process\Process1.xml");
XmlNode Validations = originalXml.SelectSingleNode("/Processes/Process[Name="Process1"]/Validations");
XmlNode Validation = originalXml.CreateNode(XmlNodeType.Element, "Validation",null);
Validation.InnerText = "This is my new Node";
Validations.AppendChild(Validation);
originalXml.Save(#"C:\Users\Sid\Desktop\Process\Process1.xml");
But, I am getting error in the line "Validations.AppendChild(validation)" as Object reference not set to an instance of an object. Please suggest some way to fix it.

You can do by this
XDocument doc = XDocument.Load(#"C:\Users\Sid\Desktop\Process\Process1.xml");
var a = doc.Descendants("Validations").FirstOrDefault();
a.Add(new XElement("Validation", "This is my new Node"));
doc.Save(#"C:\Users\Sid\Desktop\Process\Process1.xml");

Your SelectSingleNode() didn't match any element, hence the null-reference exception. Beside the conflicting double-quotes problem, you should use #attribute_name pattern to reference attribute using XPath. So the correct expression would be :
originalXml.SelectSingleNode("/Processes/Process[#Name='Process1']/Validations");

C#: Read XML Attribute

Using C#2.0 and VIsualStudio2005
I'm trying to access the "DisplayName" inside "MonitorResponseRecord"
from an XML file like the one Below:
<Magellan xsi:schemaLocation="http://tempuri.org/XMLSchema.xsd ..\Schema\Configuration.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://tempuri.org/XMLSchema.xsd">
<SchemaVersion>1.0</SchemaVersion>
<MonitorScope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" id="CleanStationChemicalManifoldFeed5" xmlns="http://tempuri.org/XMLSchema.xsd">
<PersonalSafety>
<MonitorResponseRecord Enabled="true" DisplayName="ChemicalManifoldFeed5ControllerFault">
<ExpressionMonitor>
<Expression>(ChemicalManifold.Feed5.DispenseValve = Open) and ((ChemicalManifold.Feed5.ViolatedRegion = HighProcess) or (ChemicalManifold.Feed5.ViolatedRegion = LowProcess) or (ChemicalManifold.Feed5.ViolatedRegion = Minimum))</Expression>
<TestInterval>0.1</TestInterval>
<MinimumTimeBetweenResponses>5</MinimumTimeBetweenResponses>
</ExpressionMonitor>
<Response>
<PostAlarm>
<AlarmName>ChemicalManifold_Feed5_ControllerFault</AlarmName>
<Parameter1 />
<Parameter2>Alarm Region = {ChemicalManifold.Feed5.ViolatedRegion}</Parameter2>
<Parameter3>{RecipeName}-{StepName}</Parameter3>
<Parameter4>FlowSetpoint = {ChemicalManifold.Feed5.Setpoint}-LPM, ActualFlow = {ChemicalManifold.Feed5.FlowMeter}-LPM</Parameter4>
</PostAlarm>
<ResponseEvent>
<TargetResource />
<Event>PA</Event>
<Reason>ChemicalSupply</Reason>
</ResponseEvent>
</Response>
</MonitorResponseRecord>
</PersonalSafety>
<PersonalSafety>
<MonitorResponseRecord Enabled="true" DisplayName = "PressureValveFailure">
...
...
...and soon
My current C# attempt is as follows, BUT it always hangs up when I try to XmlDocument.Load("");
XmlDocument doc = new XmlDocument();
doc.Load("../UMC0009.Configuration.Root.xml");
string attrVal = doc.SelectSingleNode("MonitorResponseRecord/#DisplayName").Value;
BUUUUT won't work :/ any help out there?
UPDATE:
the exception I recieve is as follows, and occures at the doc.Load("...") line:
{"Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function."} System.Exception {System.Xml.XPath.XPathException}

Your XPath query will be relative to the document root:
doc.SelectSingleNode("MonitorResponseRecord/#DisplayName")
To make it search anywhere in the doc prefix it with double slash:
doc.SelectSingleNode("//MonitorResponseRecord/#DisplayName")
If that still doesn't work I would try the above example after stripping out all those namespace declarations on the two root nodes.
Otherwise, with the namespace declarations you may find you need to define XML namespace mappings and use prefixes in your XPath like:
XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("x", "http://tempuri.org/XMLSchema.xsd");
doc.SelectSingleNode("//x:MonitorResponseRecord/#DisplayName")

What about:
XmlDocument doc = new XmlDocument();
doc.Load("UMC0009.Configuration.Root.xml");
XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("ns", "http://tempuri.org/XMLSchema.xsd");
string attrVal = doc.SelectSingleNode("//ns:MonitorResponseRecord/#DisplayName", nsmgr).Value;
Using a namespace manager, specify your namespace URI and use it in your XPath.
It works for me.

Selecting values from an xml document object with XPATH in code behind (c#)

I am trying to select specific values from a xml document using XPath. The xml is stored into a string varibale "tmp". This xml is the result of a query performed on a external API.
sample XML contents:
<?xml version="1.0" encoding="ISO-8859-1"?>
<Results>
<Checks>
<Check id="wbc">
<Linespeed>6000 </Linespeed>
<Provider>BT WBC </Provider>
</Check>
<Check id="adsl">
<Linespeed>2048 </Linespeed>
<Provider>BT ADSL </Provider>
</Check>
</Checks>
</Results>
Using XPATH in code behind I want to be able to select the and only for id=adsl, then store the value in a string variable for later use. I want to achieve this withouth the use of a separate xslt stylesheet.
Here is the code I have written for this but I am getting an error:
//Creating an XPATH epression
String strExpression1;
strExpression1 = "Results/Checks/Check[#id = 'adsl']/Linespeed";
//Loading the xml document
XmlDocument doc;
doc = new XmlDocument();
doc.LoadXml(tmp);
//Create an XmlNamespaceManager to resolve the default namespace.
XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("bk", "urn:schemas-microsoft-com:xslt");
//Selecting Linespeed from Check id='adsl'
XmlNode Check;
XmlElement root = doc.DocumentElement;
Check = root.SelectSingleNode(strExpression1, nsmgr);
//Assigning the the results of the XPATH expression to the variable Linespeedval
string Linespeedval = Check.ToString();
//Adding a control to display the xpath results of the "tmp" xml objectt
AvailabilityCheckerResults2.Controls.Add(new LiteralControl(Linespeedval));
Any assistance will be greately appreciated! Thanks in advance!

strExpression1 = "/Results/Checks/Check[#id = 'adsl']/Linespeed";
//or strExpression1 = "//Checks/Check[#id = 'adsl']/Linespeed";
//doc has no namespace
Check = root.SelectSingleNode(strExpression1);
....
string Linespeedval = Check.InnerText;

Take a look at this article. It has step by step instruction to parse xml using xpath.
How to query XML with an XPath expression by using Visual C#

How to correctly parse an XML document with arbitrary namespaces

I am trying to parse somewhat standard XML documents that use a schema called MARCXML from various sources.
Here are the first few lines of an example XML file that needs to be handled...
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<marc:collection xmlns:marc="http://www.loc.gov/MARC21/slim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/MARC21/slim http://www.loc.gov/standards/marcxml/schema/MARC21slim.xsd">
<marc:record>
<marc:leader>00925njm 22002777a 4500</marc:leader>
and one without namespace prefixes...
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<collection xmlns="http://www.loc.gov/MARC21/slim">
<record>
<leader>01142cam 2200301 a 4500</leader>
Key point: in order to get the XPaths to resolve further along in the program I have to go through a regex routine to add the namespaces to the NameTable (which doesn't add them by default). This seems unnecessary to me.
Regex xmlNamespace = new Regex("xmlns:(?<PREFIX>[^=]+)=\"(?<URI>[^\"]+)\"", RegexOptions.Compiled);
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xmlRecord);
XmlNamespaceManager nsMgr = new XmlNamespaceManager(xmlDoc.NameTable);
MatchCollection namespaces = xmlNamespace.Matches(xmlRecord);
foreach (Match n in namespaces)
{
nsMgr.AddNamespace(n.Groups["PREFIX"].ToString(), n.Groups["URI"].ToString());
}
The XPath call looks something like this...
XmlNode leaderNode = xmlDoc.SelectSingleNode(".//" + LeaderNode, nsMgr);
Where LeaderNode is a configurable value and would equal "marc:leader" in the first example and "leader" in the second example.
Is there a better, more efficient way to do this? Note: suggestions for solving this using LINQ are welcome, but I would mainly like to know how to solve this using XmlDocument.
EDIT: I took GrayWizardx's advice and now have the following code...
if (LeaderNode.Contains(":"))
{
string prefix = LeaderNode.Substring(0, LeaderNode.IndexOf(':'));
XmlNode root = xmlDoc.FirstChild;
string nameSpace = root.GetNamespaceOfPrefix(prefix);
nsMgr.AddNamespace(prefix, nameSpace);
}
Now there's no more dependency on Regex!

If you know there is going to be a given element in the document (for instance the root element) you could try using GetNamespaceOfPrefix.