Get XmlNode Open Tag with Attributes - c#

Is it possible to get the open tag from a XmlNode with all attributes, namespace, etc?
eg.
<root xmlns="urn:..." rattr="a">
<child attr="1">test</child>
</root>
I would like to retrieve the entire opening tag, exactly as retrieved from the original XML document if possible, from the XmlNode and later the closing tag. Both as strings.
Basically XmlNode.OuterXml without the child nodes.
EDIT
To elaborate, XmlNode.OuterXml on a node that was created with the XML above would return the entire XML fragment, including child nodes as a single string.
XmlNode.InnerXml on that same fragment would return the child nodes but not the parent node, again as a single string.
But I need the opening tag for the XML fragment without the children nodes. And without building it using the XmlAttribute array, LocalName, Namespace, etc.
This is C# 3.5
Thanks

Is there some reason you can't simply say:
string s = n.OuterXml.Substring(0, n.OuterXml.IndexOf(">") + 1);

I think the simplest way would be to call XmlNode.CloneNode(false) which (according to the docs) will clone all the attributes but not child nodes. You can then use OuterXml - although that will give you the closing tag as well.
For example:
using System;
using System.Xml;
public class Test
{
static void Main()
{
XmlDocument doc = new XmlDocument();
doc.LoadXml(#"<root xmlns='urn:xyz' rattr='a'>
<child attr='1'>test</child></root>");
XmlElement root = doc.DocumentElement;
XmlNode clone = root.CloneNode(false);
Console.WriteLine(clone.OuterXml);
}
}
Output:
<root xmlns="urn:xyz" rattr="a"></root>
Note that this may not be exactly as per the original XML document, in terms of the ordering of attributes etc. However, it will at least be equivalent.

How about:
xmlNode.OuterXML.Replace(xmlNode.InnerXML, String.Empty);
Poor man's solution :)

Related

Capture attributes in XML in C#

I'm trying to capture the attribute "description" in this XML:
<ProductoModel xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WebApi.Models">
<descripcion>descripcion 1</descripcion>
<fecha_registro>2016-03-01</fecha_registro>
<id_producto>1</id_producto>
<id_proveedor>1</id_proveedor>
<nombre_producto>producto 1</nombre_producto>
<precio>200</precio>
</ProductoModel>
My Code :
XmlDocument xDoc = new XmlDocument();
xDoc.LoadXml(content);
XmlNamespaceManager manager = new XmlNamespaceManager(xDoc.NameTable);
manager.AddNamespace("MYNS", "http://schemas.datacontract.org/2004/07/WebApi.Models");
XmlNode node = xDoc.DocumentElement.SelectSingleNode("MYNS:ProductoModel", manager);
MessageBox.Show(node.Attributes.GetNamedItem("descripcion").Value);
The problem is I can not capture the attribute "descripcion" and get the following error:
Object reference not set to an instance of an object.
As I can capture the required attribute?
<descripcion> is not attribute. It is element.
You can get any element (or attribute) with a single xpath query.
XmlNode node = xDoc.DocumentElement.SelectSingleNode("/MYNS:ProductoModel/MYNS:descripcion", manager);
MessageBox.Show(node.InnerText);
Note the character / at the beginning of the xpath expression.
If you want another easy way operate XML, check this out. This is a little tool for xml operate, it's much easier to use and understand than XmlNode.

Adding a root element to XML

I have an XML string which has the following structure:
<Element>
<Property1>Something</Propert1>
<Property2>SomethingElse</Property2>
</Element>
<Element>
<Property1>Something2</Propert1>
<Property2>SomethingElse2</Property2>
</Element>
I would like to serialize this to a List<Element>.
I use this code:
XmlSerializer xd = new XmlSerializer(typeof(T));
XDocument xdoc = XDocument.Parse(xmlStringToDesirialize);
T deserializedObject = xd.Deserialize(xdoc.CreateReader()) as T;
Where T is List<Element>. I get an exception saying There are multiple root elements. I understand why this is, but I`m not sure what to do about it.
I was thinking that adding a psudo-root element, like <Elements> might be a good solution, but I don't know how I would go about adding it to the XML document I already have.
Or maybe there is an alternative solution altogether.
EDIT: For completeness I am adding code for the full solution I needed for deserialization, in case anyone needs it.
I created a class:
[XmlRoot("myRoot", Namespace = "")]
public class MyRoot
{
[XmlElement("Element", Namespace = "{The xmlns of the actual class}")]
public List<Element> Elements {get; set;}
public MyRoot()
{
Elements = new List<Element>();
}
}
Then I deserialize to this class after adding the tags as suggested by #Richard.
Hope this can help someone.
I have an XML string
No you don't. You have something that can be refered to as an "XML Fragment". Specifically because there is not a single root element it is not an XML document. (There is no such thing as "Invalid XML": it is either valid or it is not XML).
XML Parsers require an XML document. But XmlSeriailsie is not just a parse: it includes an XML parser (of course) but also wants to generate an object graph from the content of the XML document making lots of assumptions about type availability and restrictions on the XML to match those types
The easiest approach with normal XML parsers would be to add a root element yourself. eg.:
var xdoc = XDocument.Parse("<myRoot>" + theString + "</myRoot>");
however for XML Deserialisation you will need to modify your available types to include a container that serialises with a myRoot element and then contains the relevant information.
However given the sample XML I see no sign of that looking like an object graph. Why not work with the parsed XML and extract the content using the parser's API?
XML must have 1! root element. So as you said before making <elements> as root node is solution.
And XML would look like:
<Elements>
<Element>
<Property1>Something</Propert1>
<Property2>SomethingElse</Property2>
</Element>
<Element>
<Property1>Something2</Propert1>
<Property2>SomethingElse2</Property2>
</Element>
</Elements>
why not create an element then append yours to it
XElement root = new XElement("root");
then append your elements to it

How to deal with namespaces in XML in XmlDocument c#

I have several XML documents, all of which have the same structure (element names, attribute names and hierarchy).
However, some of the elements and attribute have custom namespaces in each XML document which are not known at design time. They change, don't ask...
How can I deal with this when traversing the documents using a single set of XPath?
Should I remove all the namespaces before processing?
Can I automatically register all namespaces with an XmlNamespaceManager?
Any thoughts?
Update: some examples (with namespace declarations omitted for clarity):
<root>
<child attr="val" />
</root>
<root>
<x:child attr="val" />
</root>
<root>
<y:child z:attr="val" />
</root>
Thanks
Suppose you have following xml:
<root xmlns="first">
<el1 xmlns="second">
<el2 xmlns="third">...
You can write you queries to ignore namespaces in the following way:
/*[local-name()='root']/*[local-name()='el1']/*[local-name()='el2']
etc.
Of course you can iterate over the whole document to get namespaces and load them into nsmanager. But in general case this will cause you to evaluate every node in the document. In this case it will be faster to just treat document as a tree of objects and don't use XPath.
I believe you'll find some good insight in this Stackoverflow thread
XPath + Namespace Driving me crazy
In my opinion you have either of two solutions:
1- If the set of all possible namespaces are know before hand, then you can register them all in a XmlNamespaceManager before you begin parsing
2- Use Xpath namespace-agnostic selectors
Of course you can always scrub the xml document from any inline namespaces and start your parsing on a clean unfiorm xml without namespace.. but honestly I don't see the gain in adding this overhead step.
Scott Hanselman has a nice article about extracting all of the XML Namespaces in an XML document. Presumably, when you get all of the XML Namespaces, you can just iterate over all of them and register them in your namespace manager.
You could try something like this to strip the namespaces:
//Implemented based on interface, not part of algorithm
public string RemoveAllNamespaces(string xmlDocument)
{
return RemoveAllNamespaces(XElement.Parse(xmlDocument)).ToString();
}
//Core recursion function
private XElement RemoveAllNamespaces(XElement xmlDocument)
{
if (!xmlDocument.HasElements)
{
XElement xElement = new XElement(xmlDocument.Name.LocalName);
xElement.Value = xmlDocument.Value;
return xElement;
}
return new XElement(xmlDocument.Name.LocalName, xmlDocument.Elements().Select(el => RemoveAllNamespaces(el)));
}
See Peter Stegnar's answer here for more details:
How to remove all namespaces from XML with C#?
You can also use direct node tests with wildcards, which will match any namespace (or lack thereof):
$your-document/*:root/*:child/#*:attr

Parse XML in C#

Hello I want to know how can I parse this simple XML file content in C#. I can have multiple "in" elements, and from those I want to use date, min, max and state child values.
<out>
<in>
<id>16769</id>
<date>29-10-2010</date>
<now>12</now>
<min>12</min>
<max>23</max>
<state>2</state>
<description>enter text</description>
</in>
<in>
<id>7655</id>
<date>12-10-2010</date>
<now>1</now>
<min>1</min>
<max>2</max>
<state>0</state>
<description>enter text</description>
</in>
</out>
The System.XML namespace has all sorts of tools for parsing, reading, and writing XML data. By the way, your XML isn't well-formed; you've got two <out> elements, but only one </out> element.
Linq to xml is also helpful for parsing xml -
http://msdn.microsoft.com/en-us/library/bb387098.aspx
Also -
http://msdn.microsoft.com/library/bb308960.aspx
You need System.XML, starting with XmlDocument.Load(filename).
Once you have the XmlDocument loaded, you can drill down into it as needed using the built-in .Net XML object model, starting from XmlDocument level. You can walk the tree recursively in a pretty intuitive way, capturing what you want from each XmlNode as you go.
Alternatively (and preferably) you can quickly locate all XmlNodes in your XmlDocument that match certain conditions using XPath - examples here. An example of usage in C# is XmlNode.SelectNodes.
using System;
using System.IO;
using System.Xml;
public class Sample {
public static void Main() {
XmlDocument doc = new XmlDocument();
doc.Load("booksort.xml");
XmlNodeList nodeList;
XmlNode root = doc.DocumentElement;
nodeList=root.SelectNodes("descendant::book[author/last-name='Austen']");
//Change the price on the books.
foreach (XmlNode book in nodeList)
{
book.LastChild.InnerText="15.95";
}
Console.WriteLine("Display the modified XML document....");
doc.Save(Console.Out);
}
}
Examples can be found here http://www.c-sharpcorner.com/uploadfile/mahesh/readwritexmltutmellli2111282005041517am/readwritexmltutmellli21.aspx
This might be beyond what you want to do, but worth mentioning...
I hate parsing XML. Seriously, I almost refuse to do it, especially since .NET can do it for me. What I would do is create an "In" object that has the properties above. You probably have one already, or it would take 60 seconds to create. You'll also need a List of In objects called "Out".
Then just deserialze the XML into the objects. This takes just a few lines of code. Here is an example. BTW, this makes changing and re-saving the data just as easy.
How to serialize/deserialize

Calling the DescendantNodes without repeating each node

I have an xml that I would like to get all of its elements. I tried getting those elements by Descendants() or DescendantNodes(), but both of them returned me repeated nodes
For example, here is my xml:
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<FirstElement xsi:type="myType">
<SecondElement>A</SecondElement>
</FirstElement>
</Root>
and when I use this snippet:
XElement Elements = XElement.Parse(XML);
IEnumerable<XElement> xElement = Elements.Descendants();
IEnumerable<XNode> xNodes = Elements.DescendantNodes();
foreach (XNode node in xNodes )
{
stringBuilder.Append(node);
}
it gives me two nodes but repeating the <SecondElement>. I know Descendants call its children, and children of a child all the time, but is there any other way to avoid it?
Then, this is the content of my stringBuilder:
<FirstElement xsi:type="myType" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<SecondElement>A</SecondElement>
</FirstElement>
<SecondElement>A</SecondElement>
Well do you actually want all the descendants or just the top-level elements? If you only want the top level ones, then use the Elements() method - that returns all the elements directly under the current node.
The problem isn't that nodes are being repeated - it's that the higher-level nodes include the lower level nodes. So the higher-level node is being returned, then the lower-level one, and you're writing out the whole of both of those nodes, which means you're writing out the lower-level node twice.
If you just write out, say, the name of the node you're looking at, you won't see a problem. But you haven't said what you're really trying to do, so I don't know if that helps...
XmlDocument doc = new XmlDocument();
doc.LoadXml(XML);
XmlNodeList allElements = doc.SelectNodes("//*");
foreach(XmlElement element in allElements)
{
// your code here
}

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