How to set XmlWriter.XmlWriterSettings when created from XPathNavigator.AppendChild()? - c#

I need to set the OmitXmlDeclaration property of the XmlWriterSettings for a XmlWriter to false to not have XML declarations created. The issue is that I have created the XmlWriter from a call of a XPathNavigator.AppendChild() method. Code below:
public String GetEntityXml<T>(List<T> entities)
{
XmlDocument xmlDoc = new XmlDocument();
XPathNavigator nav = xmlDoc.CreateNavigator();
using (XmlWriter writer = nav.AppendChild())
{
XmlSerializer ser = new XmlSerializer(typeof(List<T>), new XmlRootAttribute(typeof(T).Name + "_LIST"));
ser.Serialize(writer, entities);
}
StringWriter stringWriter = new StringWriter();
XmlTextWriter xmlTextWriter = new XmlTextWriter(stringWriter);
xmlDoc.WriteTo(xmlTextWriter);
string resultString = stringWriter.ToString();
stringWriter.Close();
xmlTextWriter.Close();
return resultString;
}
Any idea how to serialize the List and not have XML declarations?


I’m not getting the XML declaration when I execute your code. Serializing a List<int> gives me:
<Int32_LIST xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<int>5</int>
<int>7</int>
<int>2</int>
</Int32_LIST>
Note that the “XML declaration” that OmitXmlDeclaration refers to is typically something similar to:
<?xml version="1.0" encoding="UTF-8" ?>
If you’re instead referring to the xmlns parts, then those are called “XML namespace declarations”, and may be eliminated by initializing an XmlSerializerNamespaces instance with a default empty namespace, and passing it to your Serialize method:
XmlSerializer ser = new XmlSerializer(typeof(List<T>), new XmlRootAttribute(typeof(T).Name + "_LIST"));
var namespaces = new XmlSerializerNamespaces(new[] { new XmlQualifiedName("", "") });
ser.Serialize(writer, entities, namespaces);
The below is a shortened implementation which achieves the same result as your code:
public String GetEntityXml<T>(List<T> entities)
{
var sb = new StringBuilder();
var settings = new XmlWriterSettings { OmitXmlDeclaration = true };
using (XmlWriter writer = XmlWriter.Create(sb, settings))
{
XmlSerializer ser = new XmlSerializer(typeof(List<T>), new XmlRootAttribute(typeof(T).Name + "_LIST"));
var namespaces = new XmlSerializerNamespaces(new[] { new XmlQualifiedName("", "") });
ser.Serialize(writer, entities, namespaces);
}
return sb.ToString();
}


Try this approach (switched to var for readability):
public String GetEntityXml<T>(List<T> entities)
{
var xmlDoc = new XmlDocument();
var nav = xmlDoc.CreateNavigator();
using (var sw = new StringWriter())
{
//Create an XmlWriter that will omit xml declarations
var s = new XmlWriterSettings{ OmitXmlDeclaration = true };
using (var xmlWriter = XmlWriter.Create(sw, s))
{
//Use the following to serialize without namespaces
var ns = new XmlSerializerNamespaces();
ns.Add("", "");
var ser = new XmlSerializer(typeof(List<T>),
new XmlRootAttribute(typeof(T).Name + "_LIST"));
ser.Serialize(xmlWriter, entities, ns);
}
//Pass xml string to nav.AppendChild()
nav.AppendChild(sw.ToString());
}
using (var stringWriter = new StringWriter())
{
using (var xmlTextWriter = XmlWriter.Create(stringWriter))
{
xmlDoc.WriteTo(xmlTextWriter);
}
return stringWriter.ToString();
}
}
Rather than using nav.AppendChild() to create the XmlWriter, you can create the XmlWriter separately and then just use nav.AppendChild(string) to write the XML into xmlDoc. When you create the XmlWriter yourself, you can omit the XML declaration. Also, when you serialize, you'll probably want to omit the xmlns:xsi and xmlns:xsd namespaces using the XmlSerializerNamespaces class.

Related

Serializing XmlElement too slow

XmlSerializer slows down when serializing XmlElement which include byte array about 9 MB.
How can I fix it without removing XmlElement.
static void SerializeByteArrayToXml(string filePath)
{
var array = File.ReadAllBytes(filePath);
var xmlElement = array.SerializeToXmlElement();
var serializedString = xmlElement.AsXMLString();
}
internal static XmlElement SerializeToXmlElement<T>(this T o)
{
XmlDocument doc = new XmlDocument();
using (XmlWriter writer = doc.CreateNavigator().AppendChild())
{
new XmlSerializer(o.GetType()).Serialize(writer, o);
}
return doc.DocumentElement;
}
internal static string AsXMLString<T>(this T toSerialize)
{
XmlSerializer xmlSerializer = new XmlSerializer(toSerialize.GetType());
StringWriter textWriter = new StringWriter();
//This method too slow
xmlSerializer.Serialize(textWriter, toSerialize);
return textWriter.ToString();
}

XmlSerializer - remove class name as parent element from xml output using c#

I am trying to serialize a class in c# but the output is not quite I am after. I want to get rid of one element in output xml - class name - that comes along with serialization.
My class is:
[XmlType("ADSobjotsing")]
public class ObjKompParam
{
[XmlElement("aadressTekst")]
public string Tekst;
[XmlElement("adsOid")]
public string OID;
My code is:
protected override XElement ComposeQueryBody(object InputParams)
{
ObjKompParam param = (ObjKompParam)InputParams;
var ads_o_q = new ObjKompParam();
XElement body = new XElement(SOAPNS + "Body",
new XElement(prod + "ADSobjotsing"));
var ns = new XmlSerializerNamespaces();
ns.Add("", "");
XmlSerializer serializer = new XmlSerializer(typeof(ObjKompParam),"");
XElement xe;
using (var stream = new MemoryStream())
{
serializer.Serialize(stream, param, ns);
stream.Position = 0;
using (XmlReader reader = XmlReader.Create(stream))
{
xe = XElement.Load(reader);
}
}
body.Descendants(prod + "ADSobjotsing").First().Add(new XElement(xe));
return body;
}
The output I get is:
<SOAP-ENV:Body>
<prod:ADSobjotsing>
<ADSobjotsing>
<aadressTekst>Sügise 10</aadressTekst>
</ADSobjotsing>
</prod:ADSobjotsing>
</SOAP-ENV:Body>
The xml output (body) I am after is following:
<SOAP-ENV:Body>
<prod:ADSobjotsing>
<aadressTekst>Sügise 10</aadressTekst>
</prod:ADSobjotsing>
</SOAP-ENV:Body>

I answer myself, as I worked out the solution:
XmlSerializer serializer = new XmlSerializer(typeof(ObjKompParam),"");
XElement xe;
using (var stream = new MemoryStream()) //write into stream
{
serializer.Serialize(stream, param, ns); //writer, object
stream.Position = 0;
using (XmlReader reader = XmlReader.Create(stream))
{
xe = XElement.Load(reader);
}
}
var child = xe.Descendants();
body.Descendants(prod + "ADSobjotsing").First().Add(child);
return body;
I made the new variable for object class ObjKompParam children and added children as descendants.

Add New Attribute to MemoryStream XML

I want to add
xsi:noNamespaceSchemaLocation="FullModeDataset.xsd"
and
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
as attibutes to my root node "ApplicationData" so the root node will look like this..
<ApplicationData
xsi:noNamespaceSchemaLocation="FullModeDataset.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" />
I am creating the xml from a string, outputing a string that is proper xml with this code..
var doc = new XmlDocument();
doc.LoadXml(myInputXmlString);
var ms = new MemoryStream();
var tx = XmlWriter.Create(ms,
new XmlWriterSettings
{
OmitXmlDeclaration = false,
ConformanceLevel = ConformanceLevel.Document,
Encoding = UTF8Encoding.UTF8
});
doc.Save(tx);
//I TRIED THE COMMENTED CODE BELOW BUT WITH NO SUCCESS
//XmlAttribute newAttr = doc.CreateAttribute("xsi:noNamespaceSchemaLocation");
//newAttr.Value = "FullModeDataset.xsd";
//XmlElement applicationNode = doc.DocumentElement["AppicationData"];
//applicationNode.Attributes.Append(newAttr);
//doc.Save(tx);
var xmlString = UTF8Encoding.UTF8.GetString(ms.ToArray());
how do I add these attributes to my xml string?

You need to create the attribute using the overload which takes the prefix and the namespace URL of the attribute you want to create, as shown below:
public class StackOverflow_14128649
{
public static void Test()
{
string myInputXmlString = #"<ApplicationData>
<something>else</something>
</ApplicationData>";
var doc = new XmlDocument();
doc.LoadXml(myInputXmlString);
XmlAttribute newAttr = doc.CreateAttribute(
"xsi",
"noNamespaceSchemaLocation",
"http://www.w3.org/2001/XMLSchema-instance");
newAttr.Value = "FullModeDataset.xsd";
doc.DocumentElement.Attributes.Append(newAttr);
var ms = new MemoryStream();
XmlWriterSettings ws = new XmlWriterSettings
{
OmitXmlDeclaration = false,
ConformanceLevel = ConformanceLevel.Document,
Encoding = UTF8Encoding.UTF8
};
var tx = XmlWriter.Create(ms, ws);
doc.Save(tx);
tx.Flush();
var xmlString = UTF8Encoding.UTF8.GetString(ms.ToArray());
Console.WriteLine(xmlString);
}
}

How can I make the xmlserializer only serialize plain xml?

I need to get plain xml, without the <?xml version="1.0" encoding="utf-16"?> at the beginning and xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" in first element from XmlSerializer. How can I do it?

To put this all together - this works perfectly for me:
// To Clean XML
public string SerializeToString<T>(T value)
{
var emptyNamespaces = new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty });
var serializer = new XmlSerializer(value.GetType());
var settings = new XmlWriterSettings();
settings.Indent = true;
settings.OmitXmlDeclaration = true;
using (var stream = new StringWriter())
using (var writer = XmlWriter.Create(stream, settings))
{
serializer.Serialize(writer, value, emptyNamespaces);
return stream.ToString();
}
}

Use the XmlSerializer.Serialize method overload where you can specify custom namespaces and pass there this.
var emptyNs = new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty });
serializer.Serialize(xmlWriter, objectToSerialze, emptyNs);
passing null or empty array won't do the trick

You can use XmlWriterSettings and set the property OmitXmlDeclaration to true as described in the msdn. Then use the XmlSerializer.Serialize(xmlWriter, objectToSerialize) as described here.

This will write the XML to a file instead of a string. Object ticket is the object that I am serializing.
Namespaces used:
using System.Xml;
using System.Xml.Serialization;
Code:
XmlSerializerNamespaces emptyNamespaces = new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty });
XmlSerializer serializer = new XmlSerializer(typeof(ticket));
XmlWriterSettings settings = new XmlWriterSettings
{
Indent = true,
OmitXmlDeclaration = true
};
using (XmlWriter xmlWriter = XmlWriter.Create(fullPathFileName, settings))
{
serializer.Serialize(xmlWriter, ticket, emptyNamespaces);
}

What is the simplest way to get indented XML with line breaks from XmlDocument?

When I build XML up from scratch with XmlDocument, the OuterXml property already has everything nicely indented with line breaks. However, if I call LoadXml on some very "compressed" XML (no line breaks or indention) then the output of OuterXml stays that way. So ...
What is the simplest way to get beautified XML output from an instance of XmlDocument?

Based on the other answers, I looked into XmlTextWriter and came up with the following helper method:
static public string Beautify(this XmlDocument doc)
{
StringBuilder sb = new StringBuilder();
XmlWriterSettings settings = new XmlWriterSettings
{
Indent = true,
IndentChars = " ",
NewLineChars = "\r\n",
NewLineHandling = NewLineHandling.Replace
};
using (XmlWriter writer = XmlWriter.Create(sb, settings)) {
doc.Save(writer);
}
return sb.ToString();
}
It's a bit more code than I hoped for, but it works just peachy.

As adapted from Erika Ehrli's blog, this should do it:
XmlDocument doc = new XmlDocument();
doc.LoadXml("<item><name>wrench</name></item>");
// Save the document to a file and auto-indent the output.
using (XmlTextWriter writer = new XmlTextWriter("data.xml", null)) {
writer.Formatting = Formatting.Indented;
doc.Save(writer);
}

Or even easier if you have access to Linq
try
{
RequestPane.Text = System.Xml.Linq.XElement.Parse(RequestPane.Text).ToString();
}
catch (System.Xml.XmlException xex)
{
displayException("Problem with formating text in Request Pane: ", xex);
}

A shorter extension method version
public static string ToIndentedString( this XmlDocument doc )
{
var stringWriter = new StringWriter(new StringBuilder());
var xmlTextWriter = new XmlTextWriter(stringWriter) {Formatting = Formatting.Indented};
doc.Save( xmlTextWriter );
return stringWriter.ToString();
}

If the above Beautify method is being called for an XmlDocument that already contains an XmlProcessingInstruction child node the following exception is thrown:
Cannot write XML declaration.
WriteStartDocument method has already
written it.
This is my modified version of the original one to get rid of the exception:
private static string beautify(
XmlDocument doc)
{
var sb = new StringBuilder();
var settings =
new XmlWriterSettings
{
Indent = true,
IndentChars = #" ",
NewLineChars = Environment.NewLine,
NewLineHandling = NewLineHandling.Replace,
};
using (var writer = XmlWriter.Create(sb, settings))
{
if (doc.ChildNodes[0] is XmlProcessingInstruction)
{
doc.RemoveChild(doc.ChildNodes[0]);
}
doc.Save(writer);
return sb.ToString();
}
}
It works for me now, probably you would need to scan all child nodes for the XmlProcessingInstruction node, not just the first one?
Update April 2015:
Since I had another case where the encoding was wrong, I searched for how to enforce UTF-8 without BOM. I found this blog post and created a function based on it:
private static string beautify(string xml)
{
var doc = new XmlDocument();
doc.LoadXml(xml);
var settings = new XmlWriterSettings
{
Indent = true,
IndentChars = "\t",
NewLineChars = Environment.NewLine,
NewLineHandling = NewLineHandling.Replace,
Encoding = new UTF8Encoding(false)
};
using (var ms = new MemoryStream())
using (var writer = XmlWriter.Create(ms, settings))
{
doc.Save(writer);
var xmlString = Encoding.UTF8.GetString(ms.ToArray());
return xmlString;
}
}

XmlTextWriter xw = new XmlTextWriter(writer);
xw.Formatting = Formatting.Indented;

public static string FormatXml(string xml)
{
try
{
var doc = XDocument.Parse(xml);
return doc.ToString();
}
catch (Exception)
{
return xml;
}
}

A simple way is to use:
writer.WriteRaw(space_char);
Like this sample code, this code is what I used to create a tree view like structure using XMLWriter :
private void generateXML(string filename)
{
using (XmlWriter writer = XmlWriter.Create(filename))
{
writer.WriteStartDocument();
//new line
writer.WriteRaw("\n");
writer.WriteStartElement("treeitems");
//new line
writer.WriteRaw("\n");
foreach (RootItem root in roots)
{
//indent
writer.WriteRaw("\t");
writer.WriteStartElement("treeitem");
writer.WriteAttributeString("name", root.name);
writer.WriteAttributeString("uri", root.uri);
writer.WriteAttributeString("fontsize", root.fontsize);
writer.WriteAttributeString("icon", root.icon);
if (root.children.Count != 0)
{
foreach (ChildItem child in children)
{
//indent
writer.WriteRaw("\t");
writer.WriteStartElement("treeitem");
writer.WriteAttributeString("name", child.name);
writer.WriteAttributeString("uri", child.uri);
writer.WriteAttributeString("fontsize", child.fontsize);
writer.WriteAttributeString("icon", child.icon);
writer.WriteEndElement();
//new line
writer.WriteRaw("\n");
}
}
writer.WriteEndElement();
//new line
writer.WriteRaw("\n");
}
writer.WriteEndElement();
writer.WriteEndDocument();
}
}
This way you can add tab or line breaks in the way you are normally used to, i.e. \t or \n

When implementing the suggestions posted here, I had trouble with the text encoding. It seems the encoding of the XmlWriterSettings is ignored, and always overridden by the encoding of the stream. When using a StringBuilder, this is always the text encoding used internally in C#, namely UTF-16.
So here's a version which supports other encodings as well.
IMPORTANT NOTE: The formatting is completely ignored if your XMLDocument object has its preserveWhitespace property enabled when loading the document. This had me stumped for a while, so make sure not to enable that.
My final code:
public static void SaveFormattedXml(XmlDocument doc, String outputPath, Encoding encoding)
{
XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
settings.IndentChars = "\t";
settings.NewLineChars = "\r\n";
settings.NewLineHandling = NewLineHandling.Replace;
using (MemoryStream memstream = new MemoryStream())
using (StreamWriter sr = new StreamWriter(memstream, encoding))
using (XmlWriter writer = XmlWriter.Create(sr, settings))
using (FileStream fileWriter = new FileStream(outputPath, FileMode.Create))
{
if (doc.ChildNodes.Count > 0 && doc.ChildNodes[0] is XmlProcessingInstruction)
doc.RemoveChild(doc.ChildNodes[0]);
// save xml to XmlWriter made on encoding-specified text writer
doc.Save(writer);
// Flush the streams (not sure if this is really needed for pure mem operations)
writer.Flush();
// Write the underlying stream of the XmlWriter to file.
fileWriter.Write(memstream.GetBuffer(), 0, (Int32)memstream.Length);
}
}
This will save the formatted xml to disk, with the given text encoding.

If you have a string of XML, rather than a doc ready for use, you can do it this way:
var xmlString = "<xml>...</xml>"; // Your original XML string that needs indenting.
xmlString = this.PrettifyXml(xmlString);
private string PrettifyXml(string xmlString)
{
var prettyXmlString = new StringBuilder();
var xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xmlString);
var xmlSettings = new XmlWriterSettings()
{
Indent = true,
IndentChars = " ",
NewLineChars = "\r\n",
NewLineHandling = NewLineHandling.Replace
};
using (XmlWriter writer = XmlWriter.Create(prettyXmlString, xmlSettings))
{
xmlDoc.Save(writer);
}
return prettyXmlString.ToString();
}

A more simplified approach based on the accepted answer:
static public string Beautify(this XmlDocument doc) {
StringBuilder sb = new StringBuilder();
XmlWriterSettings settings = new XmlWriterSettings
{
Indent = true
};
using (XmlWriter writer = XmlWriter.Create(sb, settings)) {
doc.Save(writer);
}
return sb.ToString();
}
Setting the new line is not necessary. Indent characters also has the default two spaces so I preferred not to set it as well.

Set PreserveWhitespace to true before Load.
var document = new XmlDocument();
document.PreserveWhitespace = true;
document.Load(filename);

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