Customizing an XML element using LINQ To XML - c#

I have the following code:
XNamespace testNM = "urn:lst-emp:emp";
XDocument xDoc;
string path = "project_data.xml";
if (!File.Exists(path))
{
xDoc = new XDocument(
new XDeclaration("1.0", "UTF-16", null),
new XElement(testNM + "Test")
);
}
else
{
xDoc = XDocument.Load(path);
}
var element = new XElement("key",
new XElement("Type", type),
new XElement("Value", value));
xDoc.Element(testNM + "Test").Add(element);
// Save to Disk
xDoc.Save(path);
which produces an output in the XML file like this:
<?xml version="1.0" encoding="utf-16"?>
<Test xmlns="urn:lst-emp:emp">
<key xmlns="">
<Type>String</Type>
<Value>somestring</Value>
</key>
</Test>
How can I get an output like this in the XML file instead?
<?xml version="1.0" encoding="utf-16"?>
<Tests xmlns="urn:lst-emp:emp">
<key name="someString">
<Type>String</Type>
<Value>somestring</Value>
</key >
</Tests>
Note its only the 3rd line that has changed in the XML file.

You can do it this way:
var element = new XElement("key",
new XAttribute("name", "someString"),
new XElement("Type", "type"),
new XElement("Value", "value"));

To provide a complete version of Bilyukov's answer, this should produce the output expected. Obviously substitute the "someString" static string with a variable populated as you wish. Changes include using XName.Get(string, string) to create the appropriate XName objects for the XElement constructors.
XNamespace testNM = "urn:lst-emp:emp";
XDocument xDoc;
string path = "project_data.xml";
if (!File.Exists(path))
{
xDoc = new XDocument(
new XDeclaration("1.0", "UTF-16", null),
new XElement(XName.Get("Tests", testNM.NamespaceName))
);
}
else
{
xDoc = XDocument.Load(path);
}
var element = new XElement(XName.Get("key", testNM.NamespaceName),
new XAttribute("name", "someString"),
new XElement("Type", type),
new XElement("Value", value));
xDoc.Element(XName.Get("Tests", testNM.NamespaceName)).Add(element);
// Save to Disk
xDoc.Save(path);

Your XML has default namespace. Descendants of the element where default namespace declared is considered in the same default namespace, unless it is explicitly declared with different namespace. That's why you need to use the same XNamespace for <key> element. :
var element = new XElement(testNM +"key",
new XAttribute("name", "someString"),
new XElement(testNM +"Type", type),
new XElement(testNM +"Value", value));

Related

How to read an argument value from xml file?

I have the code in an .xml file, I would like to assign to the field the value of the attribute from the .xml file.
.csharp
private static string camera_model_c1_set = xml_read_set_cip_c1.Descendants("root").ElementAt("camera_model_c1_set").Att
.csharp
Parameter name: value '
XDocument name_of_file_xml = new XDocument(
new XComment("document"),
new XElement("root",
new XElement("name", new XAttribute ("name2", myvalue ))
)
);
.xml
<?xml version="1.0" encoding="utf-8"?>
<!--document-->
<root>
<name name2="myvalue" />
</root>
and I want to get this "myvalue" to .cs code to:
static string new_my_var = ... (?)
I have
XDocument xml_doc = XDocument.Load(path);
I care about using XDocument in this code. (instead of XmlDocument)
Try this for reading the attribute from an xml file :
XmlDocument doc = new XmlDocument();
doc.Load("Path/document.xml");
XmlNodeList elem = doc.GetElementsByTagName("name");
static string new_my_var = elem.Attributes["name2"].Value;

Write XML with XDocument doesn't add XElements probably

I am new to C# and Linq. I am trying to write my Dictionary to file as XML. Therefore I use a foreach loop add all XElements to a root XElement. This is added to the document. But it does only add the last iteration of my loop to the document. What am I doing wrong?
Here is the code
public void ToXml(string xmlFile)
{
//Dictionary used: Values
XDocument doc = new XDocument(
new XDeclaration("1.0", "utf-8", null));
XElement xRoot = new XElement("RootElement");
doc.Add(xRoot);
Dictionary<double, double[]>.KeyCollection keys = Values.Keys;
foreach(double key in keys)
{
XElement inner = new XElement("InnerElement",
new XAttribute("value", key),
new XElement("TestValue1", Values[key][0]),
new XElement("Testvalue2", Values[key][1]),
new XElement("TestValue3", Values[key][2]),
new XElement("TestValue4", Values[key][3]),
new XElement("TestValue5", Values[key][4]),
new XElement("TestValue6", Values[key][5]));
xRoot.Add(inner);
}
doc.Save(xmlFile);
}
This is the output:
<?xml version="1.0" encoding="utf-8"?>
<RootElement>
<InnerElement value="400">
<TestValue1>0</TestValue1>
<Testvalue2>0</Testvalue2>
<TestValue3>200</TestValue3>
<TestValue4>0</TestValue4>
<TestValue5>100</TestValue5>
<TestValue6>491</TestValue6>
</InnerElement>
</RootElement>

How to write xsd:schema tag using XmlDocument

I'm trying to write a XML-document programatically.
I need to add <xsd:schema> tag to my document.
Currently I have:
var xmlDoc = new XmlDocument();
var root = xmlDoc.CreateElement("root");
xmlDoc.AppendChild(root);
var xsdSchemaElement = xmlDoc.CreateElement("schema");
xsdSchemaElement.Prefix = "xsd";
xsdSchemaElement.SetAttribute("id", "root");
root.AppendChild(xsdSchemaElement);
However, this renders to:
<root>
<schema id="root" />
</root>
How do I get the tag to be <xsd:schema>?
Already tried var xsdSchemaElement = xmlDoc.CreateElement("xsd:schema"); which simply ignores the xsd:.
Edit #1
Added method
private static XmlSchema GetTheSchema(XmlDocument xmlDoc)
{
var schema = new XmlSchema();
schema.TargetNamespace = "xsd";
return schema;
}
which is called like xmlDoc.Schemas.Add(GetTheSchema(xmlDoc)); but does not generate anything in my target XML.
Using LINQ-to-XML, you can nest XElements and XAttributess in a certain hierarchy to construct an XML document. As for namespace prefix, you can use XNamespace.
Notice that every namespace prefix, such as xsd in your case, has to be declared before it is used, something like xmlns:xsd = "http://www.w3.org/2001/XMLSchema".
XNamespace xsd = "http://www.w3.org/2001/XMLSchema";
var doc =
new XDocument(
//root element
new XElement("root",
//namespace prefix declaration
new XAttribute(XNamespace.Xmlns+"xsd", xsd.ToString()),
//child element xsd:schema
new XElement(xsd + "schema",
//attribute id
new XAttribute("id", "root"))));
Console.WriteLine(doc.ToString());
output :
<root xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:schema id="root" />
</root>

Create XML doc by LINQ, add xmlns,xmlns:xsi to it

I try to create an GPX XML document by LINQ to XML.
Everything works great, except adding xmlns, xmlns:xsi attributes to the doc. By trying it different way I get different exceptions.
My code:
XDocument xDoc = new XDocument(
new XDeclaration("1.0", "UTF-8", "no"),
new XElement("gpx",
new XAttribute("creator", "XML tester"),
new XAttribute("version","1.1"),
new XElement("wpt",
new XAttribute("lat","7.0"),
new XAttribute("lon","19.0"),
new XElement("name","test"),
new XElement("sym","Car"))
));
The output should also contain this:
xmlns="http://www.topografix.com/GPX/1/1"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd"
How can I add it by Linq to XML? I tried several ways but it does not work, exceptions during compile time.
See How to: Control Namespace Prefixes. You could use code like this:
XNamespace ns = "http://www.topografix.com/GPX/1/1";
XNamespace xsiNs = "http://www.w3.org/2001/XMLSchema-instance";
XDocument xDoc = new XDocument(
new XDeclaration("1.0", "UTF-8", "no"),
new XElement(ns + "gpx",
new XAttribute(XNamespace.Xmlns + "xsi", xsiNs),
new XAttribute(xsiNs + "schemaLocation",
"http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd"),
new XAttribute("creator", "XML tester"),
new XAttribute("version","1.1"),
new XElement(ns + "wpt",
new XAttribute("lat","7.0"),
new XAttribute("lon","19.0"),
new XElement(ns + "name","test"),
new XElement(ns + "sym","Car"))
));
You have to specify the namespace for each element, because that's what using xmlns this way means.
From http://www.falconwebtech.com/post/2010/06/03/Adding-schemaLocation-attribute-to-XElement-in-LINQ-to-XML.aspx:
To generate the following root node and namespaces:
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:SchemaLocation="http://www.foo.bar someSchema.xsd"
xmlns="http://www.foo.bar" >
</root>
Use the following code:
XNamespace xsi = XNamespace.Get("http://www.w3.org/2001/XMLSchema-instance");
XNamespace defaultNamespace = XNamespace.Get("http://www.foo.bar");
XElement doc = new XElement(
new XElement(defaultNamespace + "root",
new XAttribute(XNamespace.Xmlns + "xsi", xsi.NamespaceName),
new XAttribute(xsi + "schemaLocation", "http://www.foo.bar someSchema.xsd")
)
);
Be aware - if you want to add elements to the document, you need to specify the defaultNamespace in the element name or you will get xmlns="" added to your element. For example, to add a child element "count" to the above document, use:
xdoc.Add(new XElement(defaultNamespace + "count", 0)

How do I add multiple Namespace declarations to an XDocument?

I'm using an XDocument to build an Xml document in a known structure. The structure I am trying to build is as follows:
<request xmlns:ns4="http://www.example.com/a" xmlns:ns3="http://www.example.com/b" xmlns:ns2="http://www.example.com/c" >
<requestId>d78d4056-a831-4c7d-a357-d14402f623fc</requestId>
....
</request>
Notice the "xmlns:nsX" attributes.
I am trying, without success, to add these attributes to my "request" element.
XNamespace ns4 = XNamespace.Get("http://www.example.com/a");
XNamespace ns3 = XNamespace.Get("http://www.example.com/b");
XNamespace ns2 = XNamespace.Get("http://www.example.com/c");
XDocument doc = new XDocument(
new XDeclaration("1.0", "utf-8", "no"),
new XElement("request",
new XAttribute("ns4", ns4),
new XAttribute("ns3", ns3),
new XAttribute("ns2", ns2),
new XElement("requestId", Guid.NewGuid())
)
);
However, this produces the following:
<request ns4="http://www.example.com/a" ns3="http://www.example.com/b" ns2="http://www.example.com/c">
<requestId>38b07cfb-5e41-4d9a-97c8-4740c0432f11</requestId>
</request>
How do I add the namespace declarations correctly?
Do you mean:
new XAttribute(XNamespace.Xmlns + "ns4", ns4),
new XAttribute(XNamespace.Xmlns + "ns3", ns3),
new XAttribute(XNamespace.Xmlns + "ns2", ns2),

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