Little help using XmlTextWriter on writing "xhtml:link" element of sitemap.xml - c#

Hello I'm trying to write a string like :
<xhtml:link rel="alternate" hreflang="de" href="http://www.example.com/de" />
using XmlTextWriter class
I've tried this piece of code:
// Write Alternative links
_writer.WriteStartElement("xhtml:link");
_writer.WriteAttributeString("rel","alternate");
_writer.WriteAttributeString("hreflang", "de");
_writer.WriteAttributeString("href", "http://example.com/de");
_writer.WriteEndElement();
Which generates this error:
Namespace prefix xhtml on link is not defined
But I don't need any namespaces provided for xhtml:link
Question: How to achieve the string that I need using XmlTextWriter?
Update 1: I have changed to LINQ to XML
But for now I have another problem... For the beginning I'll show the code:
private readonly XNamespace nsXhtml = "http://www.w3.org/1999/xhtml";
private readonly XNamespace nsSitemap = "http://www.sitemaps.org/schemas/sitemap/0.9";
private readonly XNamespace nsXsi = "http://www.w3.org/2001/XMLSchema-instance";
private readonly XNamespace nsLocation = "http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd";
public XDocument Generate()
{
var sitemap = new XDocument(new XDeclaration("1.0", "utf-8", "yes"));
var urlSet = new XElement(nsSitemap + "urlset",
new XAttribute("xmlns", nsSitemap),
new XAttribute(XNamespace.Xmlns + "xhtml", nsXhtml),
new XAttribute(XNamespace.Xmlns + "xsi", nsXsi),
new XAttribute(nsXsi + "schemaLocation", nsLocation),
from node in GenerateUrlNodes() // Provides a collection of "objects", actually it doesn't matter since we anyway convert them to XElement below...
select WriteUrlLocation(node.Url,node.UpdateFrequency,node.LastModified));
sitemap.Add(urlSet);
return sitemap;
}
protected XElement WriteUrlLocation(string url, UpdateFrequency updateFrequency, DateTime lastUpdated)
{
var urlNode = new XElement(nsSitemap + "url",
new XElement(nsSitemap + "loc", url),
new XElement(nsSitemap + "changefreq", updateFrequency),
new XElement(nsSitemap + "lastmod", lastUpdated)
);
var linkNode = new XElement(nsXhtml + "link",
new XAttribute("rel", "alternate"),
new XAttribute("hreflang", "de"),
new XAttribute("href", "http://example.com/de"));
urlNode.Add(linkNode);
return urlNode;
}
The problem is that When I inspect the Generated sitemap at Controller:
public ActionResult Sitemap()
{
var sitemap = _sitemapGenerator.Generate().ToString();
return Content(sitemap,"text/xml");
}
The whole xml is not as expected and, the <xhtml:link> element is rendered with a non-empty closing tag (thus I don't know if this is a problem here) .. Look at the image please
Update 2: Solved! Seems that the XML structure is valid but the browser is not displaying it right...

You should change to use a different overload of XmlWriter.StartElement. For example:
_writer.WriteStartElement("link", "http://www.w3.org/1999/xhtml");
That assumes you've already got a prefix alias of xhtml for the namespace http://www.w3.org/1999/xhtml. I'd still recommend shifting to use LINQ to XML as soon as you can though... XmlWriter is great for cases where you really need to stream the data (e.g. when it's huge) but otherwise, LINQ to XML makes things a lot easier:
XNamespace xhtml = "http://www.w3.org/1999/xhtml";
var element = new XElement(xhtml + "link",
new XAttribute("rel", "alternate"),
new XAttribute("hreflang", "de"),
new XAttribute("href", "http://example.com/de"));
parent.Add(element);

If you will use XML Writer and write this
<xhtml:link rel="alternate" hreflang="en" href="www.yoursite.com" />
you can choose this code for .NET CORE 2.0:
foreach (SitemapNodeAlternate a in alternate)
{
MyWriter.WriteStartElement("xhtml", "link", null);
MyWriter.WriteAttributeString("rel", "alternate");
MyWriter.WriteAttributeString("href", a.href);
MyWriter.WriteAttributeString("hreflang", a.hreflang);
MyWriter.WriteEndElement();
}

Related

Adding child nodes using c# Xdocument class

I have an xml file as given below.
<?xml version="1.0" encoding="utf-8"?>
<file:Situattion xmlns:file="test">
<file:Properties>
</file:Situattion>
I would like to add the child element file:Character using xDocument.So that my final xml would be like given below
<?xml version="1.0" encoding="utf-8"?>
<file:Situattion xmlns:file="test">
<file:Characters>
<file:Character file:ID="File0">
<file:Value>value0</file:Value>
<file:Description>
Description0
</file:Description>
</file:Character>
<file:Character file:ID="File1">
<file:Value>value1</file:Value>
<file:Description>
Description1
</file:Description>
</file:Character>
</file:Characters>
Code in c# i tried using Xdocument class is given below.
XNamespace ns = "test";
Document = XDocument.Load(Folderpath + "\\File.test");
if (Document.Descendants(ns + "Characters") != null)
{
Document.Add(new XElement(ns + "Character"));
}
Document.Save(Folderpath + "\\File.test");
At line "Document.Add(new XElement(ns + "Character"));", I am getting an error:
"This operation would create an incorrectly structured document.".
How can I add the node under "file:Characters".
You're trying to add an extra file:Character element directly into the root. You don't want to do that - you want to add it under the file:Characters element, presumably.
Also note that Descendants() will never return null - it will return an empty sequence if there are no matching elements. So you want:
var ns = "test";
var file = Path.Combine(folderPath, "File.test");
var doc = XDocument.Load(file);
// Or var characters = document.Root.Element(ns + "Characters")
var characters = document.Descendants(ns + "Characters").FirstOrDefault();
if (characters != null)
{
characters.Add(new XElement(ns + "Character");
doc.Save(file);
}
Note that I've used more conventional naming, Path.Combine, and also moved the Save call so that you'll only end up saving if you've actually made a change to the document.
Document.Root.Element("Characters").Add(new XElement("Character", new XAttribute("ID", "File0"), new XElement("Value", "value0"), new XElement("Description")),
new XElement("Character", new XAttribute("ID", "File1"), new XElement("Value", "value1"), new XElement("Description")));
Note: I have not included the namespace for brevity. You have to add those.

How to specify an xmlns for XDocument?

I tried:
textBox1.Text = new XDocument(new XDeclaration("1.0", "UTF-8", "yes"),
new XElement("root1", new XAttribute( "xmlns", #"http://example.com"), new XElement("a", "b"))
).ToString();
But I get:
The prefix '' cannot be redefined from '' to 'http://example.com' within the same start element tag.
I also tried substituting (according to an answer I found) :
XAttribute(XNamespace.Xmlns,...
But got an error as well.
Note: I'm not trying to have more than one xmlns in the document.
The way the XDocument API works with namespace-scoped names is as XName instances. These are fairly easy to work with, as long as you accept that an XML name isn't just a string, but a scoped identifier. Here's how I do it:
var ns = XNamespace.Get("http://example.com");
var doc = new XDocument(new XDeclaration("1.0", "utf-8", null));
var root = new XElement(ns + "root1", new XElement(ns + "a", "b"));
doc.Add(root);
Result:
<root1 xmlns="http://example.com">
<a>b</a>
</root1>
Note the + operator is overloaded to accept an XNamespace and a String to result in and XName instance.

Keeping Redundant Namespace Prefixes On XML Elements in C#

I'm trying to write an XML file that will be picked up and parsed by another service. In order for this to happen the XML must be formatted in a very specific way, namely:
<?xml version="1.0"?>
<Feedbacks:Feedbacks xmlns:Feedbacks="Feedbacks">
<Feedbacks:Elements>
<Feedback:XMLFeedback xmlns:Feedback="Feedback">
<Feedback:MfgUnitID></Feedback:MfgUnitID>
<Feedback:MachineId></Feedback:MachineId>
<Feedback:OperationCode></Feedback:OperationCode>
<Feedback:ItemSeqNum></Feedback:ItemSeqNum>
<Feedback:OperDispositionCd></Feedback:OperDispositionCd>
<Feedback:ItemId></Feedback:ItemId>
<Feedback:ParentItemId></Feedback:ParentItemId>
<Feedback:ItemEndSize>1821</Feedback:ItemEndSize>
<Feedback:ItemDispositionCd></Feedback:ItemDispositionCd>
<Feedback:OperStartDate></Feedback:OperStartDate>
<Feedback:OperEndDate></Feedback:OperEndDate>
</Feedback:XMLFeedback>
</Feedbacks:Elements>
</Feedbacks:Feedbacks>
with data of course between the innermost elements. Here's the issue though, no matter what I do, I can't get any of the C# classes to keep the semicolons on the innermost nodes. As far as I know these need to stay, so is there a way in C# to force it to format the nodes this way? I've tried all of the create methods that I could find in the XMLDocument class. I can get the outer nodes formatted fine, but the inner ones just keep creating problems.
Edit, sorry here's the code that makes the inner nodes.
private void AppendFile(string filename, string[] headers, Dictionary<string, string> values)
{
XmlDocument doc = new XmlDocument();
doc.Load(filename);
XmlNode node = doc.GetElementsByTagName(headers[headers.Length - 2]).Item(0);
string[] hPieces = headers[headers.Length - 1].Split(':');
XmlElement appendee = doc.CreateElement(hPieces[0].Trim(), hPieces[1].Trim(), hPieces[0].Trim());
node.AppendChild(appendee);
foreach (KeyValuePair<string, string> pair in values)
{
string[] ePieces = pair.Key.Split(':');
//XmlElement element = doc.CreateElement(ePieces[0].Trim(), string.Empty, ePieces[1].Trim());
//XmlText text = doc.CreateTextNode(pair.Value);
XmlNode innerNode = doc.CreateNode(XmlNodeType.Element, ePieces[1].Trim(), ePieces[0].Trim());
node.InnerText = pair.Value;
// element.AppendChild(text);
appendee.AppendChild(innerNode);
}
doc.Save(filename);
}
The data for the inner nodes comes in as key value pairs in the dictionary. Where the keys contain the intended name.
Edit2: This is what the file output looks like
<?xml version="1.0" encoding="utf-8"?>
<Feedbacks:Feedbacks xmlns:Feedbacks="Feedbacks">
<Feedbacks:Elements>
<Feedback:XMLFeedback xmlns:Feedback="Feedback">
<MfgUnitID></MfgUnitID>
<MachineId></MachineId>
<OperationCode</OperationCode>
<ItemSeqNum></ItemSeqNum>
<OperDispositionCd></OperDispositionCd>
<ItemId></ItemId>
<ParentItemId></ParentItemId>
<ItemEndSize></ItemEndSize>
<ItemDispositionCd></ItemDispositionCd>
<OperStartDate></OperStartDate>
<OperEndDate></OperEndDate>
</Feedback:XMLFeedback>
</Feedbacks:Elements>
</Feedbacks:Feedbacks>
You can accompish this easily with XLinq:
using System.Xml.Linq;
XNamespace ns1 = "Feedbacks";
XNamespace ns2 = "Feedback";
var doc = new XElement("Feedbacks",
new XAttribute(XNamespace.Xmlns+"Feedbacks", ns1));
doc.Add(new XElement(ns1 + "Elements",
new XElement(ns2 + "Feedback",
new XAttribute(XNamespace.Xmlns+"Feedback", ns2),
new XElement(ns2 + "Unit"))));
Gives
<Feedbacks xmlns:Feedbacks="Feedbacks">
<Feedbacks:Elements>
<Feedback:Feedback xmlns:Feedback="Feedback">
<Feedback:Unit />
</Feedback:Feedback>
</Feedbacks:Elements>
</Feedbacks>
Although I believe that your own output should be valid XML, relying on the parent namespcae.

Help in parsing XML, simple string - but I can't seem to parse it

I have the following XML:
<iq xmlns="jabber:client" to="39850777771287777738178727#guest.google.com/agsXMPP" xml:lang="en" id="sub23" from="search.google.com" type="result">
<pubsub xmlns="http://jabber.org/protocol/pubsub">
<subscription subscription="subscribed" subid="5077774B57777BD77770" node="search" jid="39850777771287777738178727#guest.google.com/agsXMPP" />
</pubsub>
</iq>
I've tried parsing with linq to sql, but it doesn't seem to understand that these are different nodes. It groups the whole iq into a single element.
Can anyone help in parsing this using XML?
The data I want to get is the subid="5077774B57777BD77770" and the id="sub23"
Thanks!
Edit:
Here's the code I have, tried doing it in two ways:
XDocument doc = XDocument.Parse("<xml>" + iq.ToString() + "</xml>");
var results = from feed in doc.Elements("xml")
select new
{
Id = (string)feed.Element("iq").Attribute("id"),
Subid = (string)feed.Element("iq").Element("pubsub").Element("subscription").Attribute("subid")
};
and
var doc = new System.Xml.XmlDocument();
doc.LoadXml(iq.ToString());
var searchId = doc.Attributes["id"];
var subid = doc.SelectSingleNode("/pubsub/subscription").Attributes["subid"];
As Dimitre pointed out, you have a namespace issue. This will work:
using System;
using System.Xml;
namespace XMLTest
{
class Program
{
static void Main(string[] args)
{
XmlDocument doc = new XmlDocument();
XmlNamespaceManager namespaces = new XmlNamespaceManager(doc.NameTable);
namespaces.AddNamespace("ns1", "jabber:client");
namespaces.AddNamespace("ns2", "http://jabber.org/protocol/pubsub");
doc.Load("xmltest.xml");
XmlNode iqNode = doc.SelectSingleNode("/ns1:iq", namespaces);
string ID = iqNode.Attributes["id"].Value;
Console.WriteLine(ID);
XmlNode subscriptionNode = doc.SelectSingleNode("/ns1:iq/ns2:pubsub/ns2:subscription", namespaces);
string subID = subscriptionNode.Attributes["subid"].Value;
Console.WriteLine(subID);
Console.ReadLine();
}
}
}
Read this for an explanation and a complete code example how to evaluate an XPath expression that contains location steps with nodes whose names are in a default namespace and are unprefixed in the XML document..
I'm not sure if this is what you're after, but it works:
XNamespace jabber = "jabber:client";
XNamespace pubsub = "http://jabber.org/protocol/pubsub";
string xmltext = "<iq xmlns=\"jabber:client\" to=\"39850777771287777738178727#guest.google.com/agsXMPP\" xml:lang=\"en\" id=\"sub23\" from=\"search.google.com\" type=\"result\">\n"
+ "<pubsub xmlns=\"http://jabber.org/protocol/pubsub\">\n"
+ "<subscription subscription=\"subscribed\" subid=\"5077774B57777BD77770\" node=\"search\" jid=\"39850777771287777738178727#guest.google.com/agsXMPP\" />\n"
+ "</pubsub>\n"
+ "</iq>";
XDocument xdoc = XDocument.Parse(xmltext);
var iqelem = xdoc.Element(jabber + "iq");
var id = iqelem.Attribute("id").Value;
var subselem = iqelem.Element(pubsub + "pubsub").Element(pubsub + "subscription");
var subid = subselem.Attribute("subid").Value;
Console.WriteLine("SubId = {0}\nId={1}", subid, id);
I concur with Dimitre - the "empty" xmlns namespace at the top is probably causing the problem. I sometimes strip these out with a regex if they're not used, otherwise play around with XmlNameSpaceManager as described

Why am I getting the extra xmlns="" using LINQ to XML?

I'm using LINQ to XML to generate a piece of XML. Everything works great except I'm throwing in some empty namespace declarations somehow. Does anyone out there know what I'm doing incorrectly? Here is my code
private string SerializeInventory(IEnumerable<InventoryInformation> inventory)
{
var zones = inventory.Select(c => new {
c.ZoneId
, c.ZoneName
, c.Direction
}).Distinct();
XNamespace ns = "http://www.dummy-tmdd-address";
XNamespace xsi = "http://www.w3.org/2001/XMLSchema-instance";
var xml = new XElement(ns + "InventoryList"
, new XAttribute(XNamespace.Xmlns + "xsi", xsi)
, zones.Select(station => new XElement("StationInventory"
, new XElement("station-id", station.ZoneId)
, new XElement("station-name", station.ZoneName)
, new XElement("station-travel-direction", station.Direction)
, new XElement("detector-list"
, inventory.Where(p => p.ZoneId == station.ZoneId).Select(plaza =>
new XElement("detector", new XElement("detector-id", plaza.PlazaId)))))));
xml.Save(#"c:\tmpXml\myXmlDoc.xml");
return xml.ToString();
}
And here is the resulting xml. I hope it renders correctly? The browser may hide the tags.
<InventoryList xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.dummy-tmdd-address">
<StationInventory xmlns="">
<station-id>999</station-id>
<station-name>Zone 999-SEB</station-name>
<station-travel-direction>SEB</station-travel-direction>
<detector-list>
<detector>
<detector-id>7503</detector-id>
</detector>
<detector>
<detector-id>2705</detector-id>
</detector>
</detector-list>
</StationInventory>
</InventoryList>
Notice the empty namespace declaration in the first child element. Any ideas how I can remedy this? Any tips are of course appreciated.
Thanks All.
Because of the missing namespace in:
new XElement("StationInventory"...
This implicitly indicates the empty namespace "" for the StationInvetory element. You should do:
new XElement(ns + "StationInventory"...
Note that you must do this for any element you create that lives in the ns namespace. The XML serializer will make sure to qualify elements with the correct namespace prefix according to scope.
Want to add to Peter Lillevold's answer.
XML Attributes don't require namespase in their XName
In addition to casting string to Xname:
The {myNamespaseName} will be casted to XNamespase on casting of "{myNamespaseName}nodeName" to XName
Also, look to the code structure that simplifies reading of the constructor method:
private readonly XNamespace _defaultNamespace = "yourNamespace";
public XElement GetXmlNode()
{
return
new XElement(_defaultNamespace + "nodeName",
new XElement(_defaultNamespace + "nodeWithAttributes",
new XAttribute("attribute1Name", "valueOfAttribute1"),
new XAttribute("attribute2Name", "valueOfAttribute2"),
"valueOfnodeWithAttributes"
)
);
}
or
public XElement GetXmlNode()
{
return
new XElement("{myNamespaseName}nodeName",
new XElement("{myNamespaseName}nodeWithAttributes",
new XAttribute("attribute1Name", "valueOfAttribute1"),
new XAttribute("attribute2Name", "valueOfAttribute2"),
"valueOfnodeWithAttributes"
)
);
}

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