looking up a value in xml C# - c#

given this xml (just a part..)
<?xml version="1.0" encoding="utf-8"?>
<translations>
<key name="BillOfMaterials">
<translation culture="en-GB"><![CDATA[Bill of materials]]>
</translation>
<translation culture="da-DK"><![CDATA[Materiale liste]]>
</translation>
</key>
<key name="TechnicalDetails">
<translation culture="en-GB">
<![CDATA[Technical details
]]>
</translation>
</key>
..
..
...i'm looking for the simplest solution to look up for instance:
so
string thisTranslation = GetTranslation("BillOfMaterials","en-GB"); //value gets to be "Bill of materials"
I have tried the linq way, but it gets rather messy with too many itherations... especially when a simple xpath is enough in xslt... But I can't seem to just do that
Thanks in advance
Edit:
- xml is physical file
- function may not find anything.....should then just return the original key name
/translations/key[#name="BillOfMaterials"]/translation[#culture="en-GB"]
is the xpath that elsewhere is usable..

I would still use LINQ to XML - there's absolutely no need for it to get messy:
XDocument doc = XDocument.Load("test.xml");
string key = "BillOfMaterials";
var element = doc.Root.Elements("key")
.Where(key => key.Attribute("name").Value == key)
.Elements("translation")
.Where(tr => tr.Attribute("culture").Value == "en-GB")
.FirstOrDefault();
string result = (string) element ?? key;
Personally I find that cleaner than using XPath (even though the XPath is undeniably shorter). It separates each section of the query more distinctly, and also if you need any namespace handling, that would be significantly simpler with LINQ to XML than messing around with namespace managers.

You can use XPathSelectElement extension method set on XElement with your XPath selector:
Load your XML into an XDocument:
var doc = XDocument.Load("path\to\file");
and then search it with XPath:
var translation = (string)doc.XPathSelectElement(string.format("/translations/key[#name=\"{0}\"]/translation[#culture=\"{1}\"]", key, culture));
if(string.IsNullOrEmpty(translation))
translation = key;
return translation;

Get you Xml document in a XmlDocument type. You can do this like:
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("<xml>"); // Can be a XML in a string, or filename, etc.
Then you can use XPath with the SelectNodes() and SelectNode() methods.
Like:
XmlNodeList xmlNodes = xmlDoc.SelectNodes("/translations/key[#name=\"BillOfMaterials\"]/translation[#culture=\"en-GB\"]");

Related

How can I get a list of XML nodes by value using C#

I'm trying to get a XmlNodeList from an XmlDocument for nodes that have a certain value, with a view to removing those nodes.
XML:
<List xmlns="http://mynamespace.com/v1">
<Category>2144</Category>
<Title>My Object</Title>
<StartPrice>30.00</StartPrice>
<ReservePrice>-999</ReservePrice>
<BuyNowPrice>-999</BuyNowPrice>
</List>
Preferably I don't want to iterate through every node and check its value. I looked at trying to use LINQ from some examples but I just don't understand it enough to even attempt it.
I feel I'm getting close-ish with XPath (https://www.w3schools.com/xml/xpath_syntax.asp) but I'm beginning to think what I want to do isn't supported.
string xml = UtilityClass.SerializeObject<Listing> ( myListing);
XmlDocument xmlDocument = new XmlDocument ();
xmlDocument.LoadXml ( xml );
XmlElement root = xmlDocument.DocumentElement;
XmlNodeList nodes = root.SelectNodes ( "//*['-999']" );
Am open to other suggestions to get the same result, i.e. remove the nodes with -999 from the Xml document.
Thanks in advance
LINQ to XML is preferred API while dealing with XML in .Net Framework since 2007.
Check it out how easy to achieve what you need in one single statement.
LINQ methods are chained one after another and self-explanatory:
Get all descendants of the root node, taking into account a default namespace.
Whatever the names of the elements.
Where element value is -999.
Convert them to a List<>.
Remove those elements from the XML document.
c#
void Main()
{
XDocument xdoc = XDocument.Parse(#"<List xmlns='http://mynamespace.com/v1'>
<Category>2144</Category>
<Title>My Object</Title>
<StartPrice>30.00</StartPrice>
<ReservePrice>-999</ReservePrice>
<BuyNowPrice>-999</BuyNowPrice>
</List>");
XNamespace ns = xdoc.Root.GetDefaultNamespace();
xdoc.Descendants(ns + "List")
.Elements()
.Where(x => x.Value.Equals("-999"))
.ToList()
.ForEach(x => x.Remove());
Console.WriteLine(xdoc);
}
Output
<List xmlns="http://mynamespace.com/v1">
<Category>2144</Category>
<Title>My Object</Title>
<StartPrice>30.00</StartPrice>
</List>

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");

How to get data from an XML File in C# using XMLDocument class?

Good Evening All, and happy weekend!.
I have been trying all day to understand how to parse my simple XML file so I can understand it enough to write a personal project I want to work on.
I have been reading articles on this site and others but cannot get past where I am :(
My XML Document is ...
<XML>
<User>
<ID>123456789</ID>
<Device>My PC</Device>
</User>
<History>
<CreationTime>27 June 2013</CreationTime>
<UpdatedTime>29 June 2013</UpdatedTime>
<LastUsage>30 June 2013</LastUsage>
<UsageCount>103</UsageCount>
</History>
<Configuration>
<Name>Test Item</Name>
<Details>READ ME</Details>
<Enabled>true</Enabled>
</Configuration>
</XML>
I am trying to get the value in the details element (READ ME). Below is my code
// Start Logging Progress
Console.WriteLine("Test Application - XML Parsing and Creating");
Console.ReadKey();
// Load XML Document
XmlDocument MyDoc = new XmlDocument(); MyDoc.Load(#"E:\MyXML.XML");
// Select Node
XmlNode MyNode = MyDoc.SelectSingleNode("XML/Configuration/Details");
// Output Node Value
Console.WriteLine(String.Concat("Details: ", MyNode.Value));
// Pause
Console.ReadKey();
My console application is running and outputing "Target: " but not giving me the detail within the element.
Can somebody see why this is happening, and perhaps give me advice if I am completely off the wheel? I have no previous knowledge in reading XML files; hence where I am now :)
Thanks! Tom
With the your XPATH expression
// Select Node
XmlNode MyNode = MyDoc.SelectSingleNode("XML/Configuration/Details");
your are selection an element so the type of the MyNode will be XmlElement but the Value of an XmlElement is always null (see on MSDN) so you need to use XmlElement.InnerText or XmlElement.InnerXml isntead.
So the changed your code to
// Output Node Value
Console.WriteLine(String.Concat("Details: ", MyNode.InnerText));
Or you can select the content of an element with using the XPATH text() function, in this case MyNode will be XmlText where you get its value with Value:
// Select Node
XmlNode MyNode = MyDoc.SelectSingleNode("XML/Configuration/Details/text()");
// Output Node Value
Console.WriteLine(String.Concat("Details: ", MyNode.Value));
As a sidenote if you are anyway learning XML manipulation in C# you should check out LINQ to XML which is another/newer way to working with XML in C#.
Just for interest, a little-known "simple" syntax is this:
XmlDocument myDoc = new XmlDocument();
myDoc.Load(#"D:\MyXML.XML");
string details = myDoc["XML"]["Configuration"]["Details"].InnerText;
Note that this (and the XPath approach) could go pop if your XML doesn't conform to the structure you're expecting, so you'd ideally put some validation in there as well.
U can use Xpath library for that (u must include "System.Xml.XPath"):
XmlDocument document = new XmlDocument();
document.Load("MyXml.xml");
XPathNavigator navigator = document.CreateNavigator();
foreach (XPathNavigator nav in navigator.Select("//Details"))
{
Console.WriteLine(nav.Value);
}
the above code iterate over every node called (Details) extracting information and print it.
If you want to retrieve a particular value from an XML file
XmlDocument _LocalInfo_Xml = new XmlDocument();
_LocalInfo_Xml.Load(fileName);
XmlElement _XmlElement;
_XmlElement = _LocalInfo_Xml.GetElementsByTagName("UserId")[0] as XmlElement;
string Value = _XmlElement.InnerText;
Value contains the text value

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.

Categories

Resources