How to stop the XMLSerializer from htmlencoding specific contents [duplicate] - c#

Is it possible via an attribute of some sort to serialize a string as CDATA using the .Net XmlSerializer?

[Serializable]
public class MyClass
{
public MyClass() { }
[XmlIgnore]
public string MyString { get; set; }
[XmlElement("MyString")]
public System.Xml.XmlCDataSection MyStringCDATA
{
get
{
return new System.Xml.XmlDocument().CreateCDataSection(MyString);
}
set
{
MyString = value.Value;
}
}
}
Usage:
MyClass mc = new MyClass();
mc.MyString = "<test>Hello World</test>";
XmlSerializer serializer = new XmlSerializer(typeof(MyClass));
StringWriter writer = new StringWriter();
serializer.Serialize(writer, mc);
Console.WriteLine(writer.ToString());
Output:
<?xml version="1.0" encoding="utf-16"?>
<MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<MyString><![CDATA[<test>Hello World</test>]]></MyString>
</MyClass>

In addition to the way posted by John Saunders, you can use an XmlCDataSection as the type directly, although it boils down to nearly the same thing:
private string _message;
[XmlElement("CDataElement")]
public XmlCDataSection Message
{
get
{
XmlDocument doc = new XmlDocument();
return doc.CreateCDataSection( _message);
}
set
{
_message = value.Value;
}
}

[XmlRoot("root")]
public class Sample1Xml
{
internal Sample1Xml()
{
}
[XmlElement("node")]
public NodeType Node { get; set; }
#region Nested type: NodeType
public class NodeType
{
[XmlAttribute("attr1")]
public string Attr1 { get; set; }
[XmlAttribute("attr2")]
public string Attr2 { get; set; }
[XmlIgnore]
public string Content { get; set; }
[XmlText]
public XmlNode[] CDataContent
{
get
{
var dummy = new XmlDocument();
return new XmlNode[] {dummy.CreateCDataSection(Content)};
}
set
{
if (value == null)
{
Content = null;
return;
}
if (value.Length != 1)
{
throw new InvalidOperationException(
String.Format(
"Invalid array length {0}", value.Length));
}
Content = value[0].Value;
}
}
}
#endregion
}

In the class to be serialized:
public CData Content { get; set; }
And the CData class:
public class CData : IXmlSerializable
{
private string _value;
/// <summary>
/// Allow direct assignment from string:
/// CData cdata = "abc";
/// </summary>
/// <param name="value">The string being cast to CData.</param>
/// <returns>A CData object</returns>
public static implicit operator CData(string value)
{
return new CData(value);
}
/// <summary>
/// Allow direct assignment to string:
/// string str = cdata;
/// </summary>
/// <param name="cdata">The CData being cast to a string</param>
/// <returns>A string representation of the CData object</returns>
public static implicit operator string(CData cdata)
{
return cdata._value;
}
public CData() : this(string.Empty)
{
}
public CData(string value)
{
_value = value;
}
public override string ToString()
{
return _value;
}
public System.Xml.Schema.XmlSchema GetSchema()
{
return null;
}
public void ReadXml(System.Xml.XmlReader reader)
{
_value = reader.ReadElementString();
}
public void WriteXml(System.Xml.XmlWriter writer)
{
writer.WriteCData(_value);
}
}

I had a similar need but required a different output format - I wanted an attribute on the node that contains the CDATA. I took some inspiration from the above solutions to create my own. Maybe it will help someone in the future...
public class EmbedScript
{
[XmlAttribute("type")]
public string Type { get; set; }
[XmlText]
public XmlNode[] Script { get; set; }
public EmbedScript(string type, string script)
{
Type = type;
Script = new XmlNode[] { new XmlDocument().CreateCDataSection(script) };
}
public EmbedScript()
{
}
}
In the parent object to be serialised, I have the following property:
[XmlArray("embedScripts")]
[XmlArrayItem("embedScript")]
public List<EmbedScript> EmbedScripts { get; set; }
I get the following output:
<embedScripts>
<embedScript type="Desktop Iframe">
<![CDATA[<div id="play_game"><iframe height="100%" src="http://www.myurl.com" width="100%"></iframe></div>]]>
</embedScript>
<embedScript type="JavaScript">
<![CDATA[]]>
</embedScript>
</embedScripts>

In my case I'm using mixed fields, some CDATA some not,
at least for me the following solution is working....
By always reading the Value field, I'm getting the contents, regardless whether CDATA or just plain text.
[XmlElement("")]
public XmlCDataSection CDataValue {
get {
return new XmlDocument().CreateCDataSection(this.Value);
}
set {
this.Value = value.Value;
}
}
[XmlText]
public string Value;
Better late than never.
Cheers

This implementation has the ability to process nested CDATA within the string you're encoding (based on John Saunders original answer).
For example, suppose you wanted to encode the following literal string into CDATA:
I am purposefully putting some <![CDATA[ cdata markers right ]]> in here!!
You would want the resultant output to look something like this:
<![CDATA[I am purposefully putting some <![CDATA[ cdata markers right ]]]]><![CDATA[> in here!!]]>
The following implementation will loop over the string, split up instances of ...]]>... into ...]] and >... and create separate CDATA sections for each.
[XmlRoot("root")]
public class Sample1Xml
{
internal Sample1Xml()
{
}
[XmlElement("node")]
public NodeType Node { get; set; }
#region Nested type: NodeType
public class NodeType
{
[XmlAttribute("attr1")]
public string Attr1 { get; set; }
[XmlAttribute("attr2")]
public string Attr2 { get; set; }
[XmlIgnore]
public string Content { get; set; }
[XmlText]
public XmlNode[] CDataContent
{
get
{
XmlDocument dummy = new XmlDocument();
List<XmlNode> xmlNodes = new List<XmlNode>();
int tokenCount = 0;
int prevSplit = 0;
for (int i = 0; i < Content.Length; i++)
{
char c = Content[i];
//If the current character is > and it was preceded by ]] (i.e. the last 3 characters were ]]>)
if (c == '>' && tokenCount >= 2)
{
//Put everything up to this point in a new CData Section
string thisSection = Content.Substring(prevSplit, i - prevSplit);
xmlNodes.Add(dummy.CreateCDataSection(thisSection));
prevSplit = i;
}
if (c == ']')
{
tokenCount++;
}
else
{
tokenCount = 0;
}
}
//Put the final part of the string into a CData section
string finalSection = Content.Substring(prevSplit, Content.Length - prevSplit);
xmlNodes.Add(dummy.CreateCDataSection(finalSection));
return xmlNodes.ToArray();
}
set
{
if (value == null)
{
Content = null;
return;
}
if (value.Length != 1)
{
throw new InvalidOperationException(
String.Format(
"Invalid array length {0}", value.Length));
}
Content = value[0].Value;
}
}
}

This works pretty well
using System.Collections.ObjectModel;
using System.Linq;
using System.Xml;
using System.Xml.Serialization;
public class CDataContent
{
public CDataContent()
{
}
public CDataContent(string content)
{
this.Content = content;
}
[XmlIgnore]
public string Content
{
get => this.CData.FirstOrDefault()?.Value;
set
{
this.CData.Clear();
this.CData.Add(new XmlDocument().CreateCDataSection(value));
}
}
[XmlText]
public Collection<XmlNode> CData { get; } = new();
public static implicit operator CDataContent(string value) => new(value);
public static implicit operator string(CDataContent value) => value.Content;
}

Related

How do you serialize a XmlText node as CDATA using XmlSerializer [duplicate]

Is it possible via an attribute of some sort to serialize a string as CDATA using the .Net XmlSerializer?
[Serializable]
public class MyClass
{
public MyClass() { }
[XmlIgnore]
public string MyString { get; set; }
[XmlElement("MyString")]
public System.Xml.XmlCDataSection MyStringCDATA
{
get
{
return new System.Xml.XmlDocument().CreateCDataSection(MyString);
}
set
{
MyString = value.Value;
}
}
}
Usage:
MyClass mc = new MyClass();
mc.MyString = "<test>Hello World</test>";
XmlSerializer serializer = new XmlSerializer(typeof(MyClass));
StringWriter writer = new StringWriter();
serializer.Serialize(writer, mc);
Console.WriteLine(writer.ToString());
Output:
<?xml version="1.0" encoding="utf-16"?>
<MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<MyString><![CDATA[<test>Hello World</test>]]></MyString>
</MyClass>
In addition to the way posted by John Saunders, you can use an XmlCDataSection as the type directly, although it boils down to nearly the same thing:
private string _message;
[XmlElement("CDataElement")]
public XmlCDataSection Message
{
get
{
XmlDocument doc = new XmlDocument();
return doc.CreateCDataSection( _message);
}
set
{
_message = value.Value;
}
}
[XmlRoot("root")]
public class Sample1Xml
{
internal Sample1Xml()
{
}
[XmlElement("node")]
public NodeType Node { get; set; }
#region Nested type: NodeType
public class NodeType
{
[XmlAttribute("attr1")]
public string Attr1 { get; set; }
[XmlAttribute("attr2")]
public string Attr2 { get; set; }
[XmlIgnore]
public string Content { get; set; }
[XmlText]
public XmlNode[] CDataContent
{
get
{
var dummy = new XmlDocument();
return new XmlNode[] {dummy.CreateCDataSection(Content)};
}
set
{
if (value == null)
{
Content = null;
return;
}
if (value.Length != 1)
{
throw new InvalidOperationException(
String.Format(
"Invalid array length {0}", value.Length));
}
Content = value[0].Value;
}
}
}
#endregion
}
In the class to be serialized:
public CData Content { get; set; }
And the CData class:
public class CData : IXmlSerializable
{
private string _value;
/// <summary>
/// Allow direct assignment from string:
/// CData cdata = "abc";
/// </summary>
/// <param name="value">The string being cast to CData.</param>
/// <returns>A CData object</returns>
public static implicit operator CData(string value)
{
return new CData(value);
}
/// <summary>
/// Allow direct assignment to string:
/// string str = cdata;
/// </summary>
/// <param name="cdata">The CData being cast to a string</param>
/// <returns>A string representation of the CData object</returns>
public static implicit operator string(CData cdata)
{
return cdata._value;
}
public CData() : this(string.Empty)
{
}
public CData(string value)
{
_value = value;
}
public override string ToString()
{
return _value;
}
public System.Xml.Schema.XmlSchema GetSchema()
{
return null;
}
public void ReadXml(System.Xml.XmlReader reader)
{
_value = reader.ReadElementString();
}
public void WriteXml(System.Xml.XmlWriter writer)
{
writer.WriteCData(_value);
}
}
I had a similar need but required a different output format - I wanted an attribute on the node that contains the CDATA. I took some inspiration from the above solutions to create my own. Maybe it will help someone in the future...
public class EmbedScript
{
[XmlAttribute("type")]
public string Type { get; set; }
[XmlText]
public XmlNode[] Script { get; set; }
public EmbedScript(string type, string script)
{
Type = type;
Script = new XmlNode[] { new XmlDocument().CreateCDataSection(script) };
}
public EmbedScript()
{
}
}
In the parent object to be serialised, I have the following property:
[XmlArray("embedScripts")]
[XmlArrayItem("embedScript")]
public List<EmbedScript> EmbedScripts { get; set; }
I get the following output:
<embedScripts>
<embedScript type="Desktop Iframe">
<![CDATA[<div id="play_game"><iframe height="100%" src="http://www.myurl.com" width="100%"></iframe></div>]]>
</embedScript>
<embedScript type="JavaScript">
<![CDATA[]]>
</embedScript>
</embedScripts>
In my case I'm using mixed fields, some CDATA some not,
at least for me the following solution is working....
By always reading the Value field, I'm getting the contents, regardless whether CDATA or just plain text.
[XmlElement("")]
public XmlCDataSection CDataValue {
get {
return new XmlDocument().CreateCDataSection(this.Value);
}
set {
this.Value = value.Value;
}
}
[XmlText]
public string Value;
Better late than never.
Cheers
This implementation has the ability to process nested CDATA within the string you're encoding (based on John Saunders original answer).
For example, suppose you wanted to encode the following literal string into CDATA:
I am purposefully putting some <![CDATA[ cdata markers right ]]> in here!!
You would want the resultant output to look something like this:
<![CDATA[I am purposefully putting some <![CDATA[ cdata markers right ]]]]><![CDATA[> in here!!]]>
The following implementation will loop over the string, split up instances of ...]]>... into ...]] and >... and create separate CDATA sections for each.
[XmlRoot("root")]
public class Sample1Xml
{
internal Sample1Xml()
{
}
[XmlElement("node")]
public NodeType Node { get; set; }
#region Nested type: NodeType
public class NodeType
{
[XmlAttribute("attr1")]
public string Attr1 { get; set; }
[XmlAttribute("attr2")]
public string Attr2 { get; set; }
[XmlIgnore]
public string Content { get; set; }
[XmlText]
public XmlNode[] CDataContent
{
get
{
XmlDocument dummy = new XmlDocument();
List<XmlNode> xmlNodes = new List<XmlNode>();
int tokenCount = 0;
int prevSplit = 0;
for (int i = 0; i < Content.Length; i++)
{
char c = Content[i];
//If the current character is > and it was preceded by ]] (i.e. the last 3 characters were ]]>)
if (c == '>' && tokenCount >= 2)
{
//Put everything up to this point in a new CData Section
string thisSection = Content.Substring(prevSplit, i - prevSplit);
xmlNodes.Add(dummy.CreateCDataSection(thisSection));
prevSplit = i;
}
if (c == ']')
{
tokenCount++;
}
else
{
tokenCount = 0;
}
}
//Put the final part of the string into a CData section
string finalSection = Content.Substring(prevSplit, Content.Length - prevSplit);
xmlNodes.Add(dummy.CreateCDataSection(finalSection));
return xmlNodes.ToArray();
}
set
{
if (value == null)
{
Content = null;
return;
}
if (value.Length != 1)
{
throw new InvalidOperationException(
String.Format(
"Invalid array length {0}", value.Length));
}
Content = value[0].Value;
}
}
}
This works pretty well
using System.Collections.ObjectModel;
using System.Linq;
using System.Xml;
using System.Xml.Serialization;
public class CDataContent
{
public CDataContent()
{
}
public CDataContent(string content)
{
this.Content = content;
}
[XmlIgnore]
public string Content
{
get => this.CData.FirstOrDefault()?.Value;
set
{
this.CData.Clear();
this.CData.Add(new XmlDocument().CreateCDataSection(value));
}
}
[XmlText]
public Collection<XmlNode> CData { get; } = new();
public static implicit operator CDataContent(string value) => new(value);
public static implicit operator string(CDataContent value) => value.Content;
}

Deserialize portion of XmlDocument into object

I see this question often enough, but nobody's title really seems to depict their question. I get a large response object back from a Web API that contains general response information, along with the data object I want to deserialize.
Full XML:
<?xml version="1.0"?>
<root>
<status>
<apiErrorCode>0</apiErrorCode>
<apiErrorMessage/>
<dbErrorCode>0</dbErrorCode>
<dbErrorMessage/>
<dbErrorList/>
</status>
<data>
<modelName>ReportXDTO</modelName>
<modelData>
<id>1780</id>
<reportTitle>Access Level (select) with Door Assignment</reportTitle>
<hasParameters>true</hasParameters>
<parameters>
<dataType>STRING</dataType>
<title>Access Level:</title>
<index>1</index>
<allowMulti>true</allowMulti>
<selectSql>SELECT DISTINCT [Name] FROM dbo.[Levels] WHERE [PrecisionFlag] = '0' ORDER BY [Name] </selectSql>
<values>
<value>Door 1</value>
<used>1</used>
</values>
<values>
<value>Door 2</value>
<used>1</used>
</values>
<values>
<value>Door 3</value>
<used>1</used>
</values>
</parameters>
<sourceSql>SELECT [Name], [SData] FROM [Schedules]</sourceSql>
<report/>
</modelData>
<itemReturned>1</itemReturned>
<itemTotal>1</itemTotal>
</data>
<listInfo>
<pageIdRequested>1</pageIdRequested>
<pageIdCurrent>1</pageIdCurrent>
<pageIdFirst>1</pageIdFirst>
<pageIdPrev>1</pageIdPrev>
<pageIdNext>1</pageIdNext>
<pageIdLast>1</pageIdLast>
<itemRequested>1</itemRequested>
<itemReturned>1</itemReturned>
<itemStart>1</itemStart>
<itemEnd>1</itemEnd>
<itemTotal>1</itemTotal>
</listInfo>
</root>
I only want to deserialize the modelData element. The modelData object type is dynamic, depending on the API call.
I deserialize xml in other applications, and created the following method, but don't know how to specifically ONLY get the modelData element:
public static T ConvertXmltoClass<T>(HttpResponseMessage http, string elementName) where T : new()
{
var newClass = new T();
try
{
var doc = JsonConvert.DeserializeXmlNode(http.Content.ReadAsStringAsync().Result, "root");
XmlReader reader = new XmlNodeReader(doc);
reader.ReadToFollowing(elementName);
//The xml needs to show the proper object name
var xml = reader.ReadOuterXml().Replace(elementName, newClass.GetType().Name);
using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(xml)))
{
var serializer = new XmlSerializer(typeof(T));
newClass = (T)serializer.Deserialize(stream);
}
}
catch (Exception e)
{
AppLog.LogException(System.Reflection.MethodBase.GetCurrentMethod().Name, e);
}
return newClass;
}
I have updated this thread multiple times now, to stay current. I started updating it with the first solution. But that solution by itself didn't solve the problem. With the code how it is right now, I get no exceptions, but don't get the xml deserialized to my object. Instead I get a new, blank object. Thoughts?
THOUGH the object type can change, here is my current object I am dealing with: (PLEASE NOTE, that I deserialize the exact xml in modelData, in the Web API)
namespace WebApiCommon.DataObjects
{
[Serializable]
public class ReportXDto
{
public ReportXDto()
{
Parameters = new List<ReportParameterXDto>();
}
public int Id { get; set; }
public string ReportTitle { get; set; }
public bool HasParameters { get; set; } = false;
public List<ReportParameterXDto> Parameters { get; set; }
public string SourceSql { get; set; }
public DataTable Report { get; set; }
}
[Serializable]
public class ReportXDto
{
public ReportXDto()
{
Parameters = new List<ReportParameterXDto>();
}
public int Id { get; set; }
public string ReportTitle { get; set; }
public bool HasParameters { get; set; } = false;
public List<ReportParameterXDto> Parameters { get; set; }
public string SourceSql { get; set; }
public DataTable Report { get; set; }
}
[Serializable]
public class ReportParameterValuesXDto
{
public string Value { get; set; } = "";
public bool Used { get; set; } = false;
}
}
Firstly, XmlSerializer is case sensitive. Thus your property names need to match the XML element names exactly -- unless overridden with an attribute that controls XML serialization such as [XmlElement(ElementName="id")]. To generate a data model with the correct casing I used http://xmltocsharp.azurewebsites.net/ which resulted in:
public class ReportParameterValuesXDto
{
[XmlElement(ElementName="value")]
public string Value { get; set; }
[XmlElement(ElementName="used")]
public string Used { get; set; }
}
public class ReportParametersXDto
{
[XmlElement(ElementName="dataType")]
public string DataType { get; set; }
[XmlElement(ElementName="title")]
public string Title { get; set; }
[XmlElement(ElementName="index")]
public string Index { get; set; }
[XmlElement(ElementName="allowMulti")]
public string AllowMulti { get; set; }
[XmlElement(ElementName="selectSql")]
public string SelectSql { get; set; }
[XmlElement(ElementName="values")]
public List<ReportParameterValuesXDto> Values { get; set; }
}
public class ReportXDto
{
[XmlElement(ElementName="id")]
public string Id { get; set; }
[XmlElement(ElementName="reportTitle")]
public string ReportTitle { get; set; }
[XmlElement(ElementName="hasParameters")]
public string HasParameters { get; set; }
[XmlElement(ElementName="parameters")]
public ReportParametersXDto Parameters { get; set; }
[XmlElement(ElementName="sourceSql")]
public string SourceSql { get; set; }
[XmlElement(ElementName="report")]
public string Report { get; set; }
}
(After generating the model, I modified the class names to match your naming convention.)
Given the correct data model, you can deserialize directly from a selected XmlNode using an XmlNodeReader as shown in How to deserialize a node in a large document using XmlSerializer without having to re-serialize to an intermediate XML string. The following extension method does the trick:
public static partial class XmlExtensions
{
public static IEnumerable<T> DeserializeElements<T>(this XmlNode root, string localName, string namespaceUri)
{
return new XmlNodeReader(root).DeserializeElements<T>(localName, namespaceUri);
}
public static IEnumerable<T> DeserializeElements<T>(this XmlReader reader, string localName, string namespaceUri)
{
var serializer = XmlSerializerFactory.Create(typeof(T), localName, namespaceUri);
while (!reader.EOF)
{
if (!(reader.NodeType == XmlNodeType.Element && reader.LocalName == localName && reader.NamespaceURI == namespaceUri))
reader.ReadToFollowing(localName, namespaceUri);
if (!reader.EOF)
{
yield return (T)serializer.Deserialize(reader);
// Note that the serializer will advance the reader past the end of the node
}
}
}
}
public static class XmlSerializerFactory
{
// To avoid a memory leak the serializer must be cached.
// https://stackoverflow.com/questions/23897145/memory-leak-using-streamreader-and-xmlserializer
// This factory taken from
// https://stackoverflow.com/questions/34128757/wrap-properties-with-cdata-section-xml-serialization-c-sharp/34138648#34138648
readonly static Dictionary<Tuple<Type, string, string>, XmlSerializer> cache;
readonly static object padlock;
static XmlSerializerFactory()
{
padlock = new object();
cache = new Dictionary<Tuple<Type, string, string>, XmlSerializer>();
}
public static XmlSerializer Create(Type serializedType, string rootName, string rootNamespace)
{
if (serializedType == null)
throw new ArgumentNullException();
if (rootName == null && rootNamespace == null)
return new XmlSerializer(serializedType);
lock (padlock)
{
XmlSerializer serializer;
var key = Tuple.Create(serializedType, rootName, rootNamespace);
if (!cache.TryGetValue(key, out serializer))
cache[key] = serializer = new XmlSerializer(serializedType, new XmlRootAttribute { ElementName = rootName, Namespace = rootNamespace });
return serializer;
}
}
}
Then you would deserialize as follows:
var modelData = doc.DeserializeElements<ReportXDto>("modelData", "").FirstOrDefault();
Working sample .Net fiddle here.
For Huge xml files always use XmlReader so you do not get an out of memory issue. See code below to get the element as a string :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
namespace ConsoleApplication1
{
class Program
{
const string FILENAME = #"c:\temp\test.xml";
static void Main(string[] args)
{
//or Create(Stream)
XmlReader reader = XmlReader.Create(FILENAME);
reader.ReadToFollowing("modelData");
if (!reader.EOF)
{
string modelDataStr = reader.ReadOuterXml();
}
}
}
}

Changing type of element in XML Serialization

I am having huge problems with XML serialization. I have two classes, both need to be serializeable. In the inherited class, I would like to change the serialization behavior, so that a string property gets serialized as complex type.
public class Animal
{
[XmlElement(ElementName = "NAME")]
public string Name { get; set; }
public virtual bool ShouldSerializeName() { return true; }
}
public class Cat : Animal
{
public override bool ShouldSerializeName() { return false; }
[XmlElement(ElementName = "NAME")]
public NameAndType Name2 { get; set; }
}
public class NameAndType
{
public string Name { get; set; }
public string Type { get; set; }
}
...
var cat = new Cat {Name2 = new NameAndType {Name = "LittleCat"}};
new XmlSerializer(typeof(Cat)).Serialize(Console.Out, cat);
I have tried different approaches, but I didn't find a way to change how the NAME element get's serialized.
With the example above, I get the error message:
The XML element 'NAME' from namespace '' is already present in the current scope. Use XML attributes to specify another XML name or namespace for the element.
The reason you get the error is that, during XmlSerializer code generation, the code generator doesn't understand that the two potential NAME elements on Cat will never be simultaneously serialized, so throws the exception.
Instead, you can apply XmlAnyElementAttribute to a virtual property returning an XElement, then manually create and return an appropriate XElement for the name for each class in the hierarchy:
[XmlInclude(typeof(Cat))]
public class Animal
{
[XmlIgnore]
public string Name { get; set; }
[XmlAnyElement]
public virtual XElement XmlName
{
get
{
return Name == null ? null : new XElement("NAME", Name);
}
set
{
Name = (value == null ? null : value.Value);
}
}
}
public class Cat : Animal
{
// Must be cached as per https://msdn.microsoft.com/en-us/library/system.xml.serialization.xmlserializer%28v=vs.110%29.aspx
static XmlSerializer nameSerializer;
static Cat()
{
nameSerializer = new XmlSerializer(typeof(NameAndType), new XmlRootAttribute("NAME"));
}
[XmlIgnore]
public NameAndType Name2 { get; set; }
[XmlAnyElement]
public override XElement XmlName
{
get
{
return (Name2 == null ? null : XObjectExtensions.SerializeToXElement(Name2, nameSerializer, true));
}
set
{
Name2 = (value == null ? null : XObjectExtensions.Deserialize<NameAndType>(value, nameSerializer));
}
}
}
Using the extension methods:
public static class XObjectExtensions
{
public static T Deserialize<T>(this XContainer element)
{
return element.Deserialize<T>(new XmlSerializer(typeof(T)));
}
public static T Deserialize<T>(this XContainer element, XmlSerializer serializer)
{
using (var reader = element.CreateReader())
{
object result = serializer.Deserialize(reader);
if (result is T)
return (T)result;
}
return default(T);
}
public static XElement SerializeToXElement<T>(this T obj)
{
return obj.SerializeToXElement(new XmlSerializer(obj.GetType()), true);
}
public static XElement SerializeToXElement<T>(this T obj, XmlSerializer serializer, bool omitStandardNamespaces)
{
var doc = new XDocument();
using (var writer = doc.CreateWriter())
{
XmlSerializerNamespaces ns = null;
if (omitStandardNamespaces)
(ns = new XmlSerializerNamespaces()).Add("", ""); // Disable the xmlns:xsi and xmlns:xsd lines.
serializer.Serialize(writer, obj, ns);
}
var element = doc.Root;
if (element != null)
element.Remove();
return element;
}
}
Which, for a List<Animal>, produces XML like this:
<ArrayOfAnimal xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Animal>
<NAME>duck</NAME>
</Animal>
<Animal xsi:type="Cat">
<NAME>
<Name>Smokey</Name>
<Type>Siamese</Type>
</NAME>
</Animal>
</ArrayOfAnimal>
You're specifying two different XML elements with the same name on the same graph level, which is not allowed.
I will offer a solution, but it involves concatenating type and name for the Cat class serialization. If it is not imperative to serialize that NameAndType class, then go on:
On Animal, set Name to be virtual;
On Cat, set XmlIgnore on Name2. Then override Name and return both properties of Name2 the way you fancy.
If you really need to serialize that class as it is, then I'm afraid you'll have to so it with a different elementName.
Edit: Sample code:
public class Animal
{
[XmlElement(ElementName = "NAME")]
public virtual string Name { get; set; }
public virtual bool ShouldSerializeName() { return true; }
}
public class Cat : Animal
{
public override bool ShouldSerializeName() { return false; }
[XmlIgnore]
public NameAndType Name2 { get; set; }
[XmlElement(ElementName = "NAME")]
public override string Name
{
get
{
return String.Format("{0} [Type:{1}]", Name2.Name, Name2.Type);
}
set { }
}
}

XML Deserialization Rules

I need to deserialize xml file and its structured this way:
<NPCs>
<LabAssistant1>
<Questions>
<Question>
<Type>CheckBox</Type>
<Points>10</Points>
<Text>Q1</Text>
<Answers>
<Answer>
<Correct>False</Correct>
<Text>A1</Text>
</Answer>
<Answer>
<Correct>True</Correct>
<Text>A2</Text>
</Answer>
<Answer>
<Correct>False</Correct>
<Text>A3</Text>
</Answer>
</Answers>
</Question>
</Questions>
</LabAssistant1>
<LabAssistant2>
<Questions>
...
</Questions>
</LabAssistant2>
</NPCs>
So as you can see am having root node NPCs and my goal is to read questions separately by LabAssistant1 name or any tag name in NPCs.
String questionsPath = path+"/questions.xml";
XmlReader reader=XmlReader.Create(new StreamReader(questionsPath));
XmlRootAttribute xmlRoot = new XmlRootAttribute();
xmlRoot.ElementName = npc;
reader.ReadToDescendant(npc);
XmlSerializer se = new XmlSerializer(typeof(Question[]),xmlRoot);
Question[] qs=se.Deserialize(reader) as Question[];
Console.WriteLine(qs.Length.ToString()); // Always 0
Above code should output 2 objects of Question as array, but it doesn't
Here are the classes Question and Answer, anything is wrong with my attached attributes?
public class Question
{
[XmlElement(ElementName="Text")]
public String Text { get; set; }
[XmlArray(ElementName = "Answers")]
public Answer[] Answers { get; set; }
[XmlElement(ElementName = "Type")]
public QuestionType Type { get; set; }
[XmlElement(ElementName = "Points")]
public int Points { get; set; }
public Question()
{
}
public Question(String text, Answer[] answers, QuestionType type,int points)
{
this.Text = text;
this.Answers = answers;
this.Type = type;
this.Points = points;
}
}
public class Answer
{
[XmlElement(ElementName="Text")]
public String Text { get; set; }
[XmlElement(ElementName = "Correct")]
public bool Correct { get; set; }
public Answer()
{
}
public Answer(String text, bool correct)
{
this.Text = text;
this.Correct = correct;
}
}
You could use the UnknownElement event of XmlSerializer to load all the lab assistants into memory, like so:
public class LabAssistant
{
static XmlSerializer listSerializer;
static LabAssistant()
{
// This must be cached to prevent memory & resource leaks.
// See http://msdn.microsoft.com/en-us/library/System.Xml.Serialization.XmlSerializer%28v=vs.110%29.aspx
listSerializer = new XmlSerializer(typeof(List<Question>), new XmlRootAttribute("Questions"));
}
public List<Question> Questions { get; set; }
public static bool TryDeserializeFromXml(XmlElement element, out string name, out LabAssistant assistant)
{
name = element.Name;
var child = element.ChildNodes.OfType<XmlElement>().Where(el => el.Name == "Questions").FirstOrDefault();
if (child != null)
{
var list = child.OuterXml.LoadFromXML<List<Question>>(listSerializer);
if (list != null)
{
assistant = new LabAssistant() { Questions = list };
return true;
}
}
assistant = null;
return false;
}
}
public class NPCs
{
public NPCs()
{
this.LabAssistants = new Dictionary<string, LabAssistant>();
}
public static XmlSerializer CreateXmlSerializer()
{
// No need to cache this.
var serializer = new XmlSerializer(typeof(NPCs));
serializer.UnknownElement += new XmlElementEventHandler(NPCs.XmlSerializer_LoadLabAssistants);
return serializer;
}
[XmlIgnore]
public Dictionary<string, LabAssistant> LabAssistants { get; set; }
public static void XmlSerializer_LoadLabAssistants(object sender, XmlElementEventArgs e)
{
var obj = e.ObjectBeingDeserialized;
var element = e.Element;
if (obj is NPCs)
{
var npcs = (NPCs)obj;
string name;
LabAssistant assistant;
if (LabAssistant.TryDeserializeFromXml(element, out name, out assistant))
npcs.LabAssistants[name] = assistant;
}
}
}
Using the following helper methods:
public static class XmlSerializationHelper
{
public static T LoadFromXML<T>(this string xmlString)
{
return xmlString.LoadFromXML<T>(new XmlSerializer(typeof(T)));
}
public static T LoadFromXML<T>(this string xmlString, XmlSerializer serial)
{
T returnValue = default(T);
using (StringReader reader = new StringReader(xmlString))
{
object result = serial.Deserialize(reader);
if (result is T)
{
returnValue = (T)result;
}
}
return returnValue;
}
}
Having done this, you now have a dictionary of lab assistants by name.
While this code will deserialize your data correctly, it won't reserialize it. Custom code to serialize the dictionary would be required.
One final note - XmlSerializer will choke on the XML you provided because it requires that Boolean values be in lowercase. Thus the following will throw an exception:
<Correct>False</Correct>
If you did not mistype the XML and it really contains Booleans in this format, you will need to manually handle these fields.
I needed to create QuestionCollection class to hold the array of questions (having typeof(Question[]) throws <TagName xmlns="> was not expected, probably because the deserializer is not smart enough).
What i do next is first reading to tag LabAssistant or any tag name, next reading to its child Questions tag and after that i deserialize the questions into QuestionCollection, so with ReadToDescendant I can access any child elements of the NPCs
String questionsPath = Application.dataPath + "/Resources/questions.xml";
XmlReader reader=XmlReader.Create(new StreamReader(questionsPath));
reader.ReadToDescendant("LabAssistant");
reader.ReadToDescendant("Questions");
XmlSerializer se = new XmlSerializer(typeof(QuestionCollection));
QuestionCollection qc=(QuestionCollection)se.Deserialize(reader);
QuestionCollection class:
[XmlType("Questions")]
public class QuestionCollection
{
[XmlElement("Question")]
public Question[] Questions { get; set; }
public QuestionCollection() { }
}
Question class
[XmlType("Question")]
public class Question
{
[XmlElement("Text")]
public String Text { get; set; }
[XmlArray("Answers")]
public Answer[] Answers { get; set; }
[XmlElement("Type")]
public QuestionType Type { get; set; }
[XmlElement("Points")]
public int Points { get; set; }
public Question() { }
}
Answer class:
[XmlType("Answer")]
public class Answer
{
[XmlElement("Text")]
public String Text { get; set; }
[XmlElement("Correct")]
public bool Correct { get; set; }
public Answer() { }
}

How do you serialize a string as CDATA using XmlSerializer?

Is it possible via an attribute of some sort to serialize a string as CDATA using the .Net XmlSerializer?
[Serializable]
public class MyClass
{
public MyClass() { }
[XmlIgnore]
public string MyString { get; set; }
[XmlElement("MyString")]
public System.Xml.XmlCDataSection MyStringCDATA
{
get
{
return new System.Xml.XmlDocument().CreateCDataSection(MyString);
}
set
{
MyString = value.Value;
}
}
}
Usage:
MyClass mc = new MyClass();
mc.MyString = "<test>Hello World</test>";
XmlSerializer serializer = new XmlSerializer(typeof(MyClass));
StringWriter writer = new StringWriter();
serializer.Serialize(writer, mc);
Console.WriteLine(writer.ToString());
Output:
<?xml version="1.0" encoding="utf-16"?>
<MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<MyString><![CDATA[<test>Hello World</test>]]></MyString>
</MyClass>
In addition to the way posted by John Saunders, you can use an XmlCDataSection as the type directly, although it boils down to nearly the same thing:
private string _message;
[XmlElement("CDataElement")]
public XmlCDataSection Message
{
get
{
XmlDocument doc = new XmlDocument();
return doc.CreateCDataSection( _message);
}
set
{
_message = value.Value;
}
}
[XmlRoot("root")]
public class Sample1Xml
{
internal Sample1Xml()
{
}
[XmlElement("node")]
public NodeType Node { get; set; }
#region Nested type: NodeType
public class NodeType
{
[XmlAttribute("attr1")]
public string Attr1 { get; set; }
[XmlAttribute("attr2")]
public string Attr2 { get; set; }
[XmlIgnore]
public string Content { get; set; }
[XmlText]
public XmlNode[] CDataContent
{
get
{
var dummy = new XmlDocument();
return new XmlNode[] {dummy.CreateCDataSection(Content)};
}
set
{
if (value == null)
{
Content = null;
return;
}
if (value.Length != 1)
{
throw new InvalidOperationException(
String.Format(
"Invalid array length {0}", value.Length));
}
Content = value[0].Value;
}
}
}
#endregion
}
In the class to be serialized:
public CData Content { get; set; }
And the CData class:
public class CData : IXmlSerializable
{
private string _value;
/// <summary>
/// Allow direct assignment from string:
/// CData cdata = "abc";
/// </summary>
/// <param name="value">The string being cast to CData.</param>
/// <returns>A CData object</returns>
public static implicit operator CData(string value)
{
return new CData(value);
}
/// <summary>
/// Allow direct assignment to string:
/// string str = cdata;
/// </summary>
/// <param name="cdata">The CData being cast to a string</param>
/// <returns>A string representation of the CData object</returns>
public static implicit operator string(CData cdata)
{
return cdata._value;
}
public CData() : this(string.Empty)
{
}
public CData(string value)
{
_value = value;
}
public override string ToString()
{
return _value;
}
public System.Xml.Schema.XmlSchema GetSchema()
{
return null;
}
public void ReadXml(System.Xml.XmlReader reader)
{
_value = reader.ReadElementString();
}
public void WriteXml(System.Xml.XmlWriter writer)
{
writer.WriteCData(_value);
}
}
I had a similar need but required a different output format - I wanted an attribute on the node that contains the CDATA. I took some inspiration from the above solutions to create my own. Maybe it will help someone in the future...
public class EmbedScript
{
[XmlAttribute("type")]
public string Type { get; set; }
[XmlText]
public XmlNode[] Script { get; set; }
public EmbedScript(string type, string script)
{
Type = type;
Script = new XmlNode[] { new XmlDocument().CreateCDataSection(script) };
}
public EmbedScript()
{
}
}
In the parent object to be serialised, I have the following property:
[XmlArray("embedScripts")]
[XmlArrayItem("embedScript")]
public List<EmbedScript> EmbedScripts { get; set; }
I get the following output:
<embedScripts>
<embedScript type="Desktop Iframe">
<![CDATA[<div id="play_game"><iframe height="100%" src="http://www.myurl.com" width="100%"></iframe></div>]]>
</embedScript>
<embedScript type="JavaScript">
<![CDATA[]]>
</embedScript>
</embedScripts>
In my case I'm using mixed fields, some CDATA some not,
at least for me the following solution is working....
By always reading the Value field, I'm getting the contents, regardless whether CDATA or just plain text.
[XmlElement("")]
public XmlCDataSection CDataValue {
get {
return new XmlDocument().CreateCDataSection(this.Value);
}
set {
this.Value = value.Value;
}
}
[XmlText]
public string Value;
Better late than never.
Cheers
This implementation has the ability to process nested CDATA within the string you're encoding (based on John Saunders original answer).
For example, suppose you wanted to encode the following literal string into CDATA:
I am purposefully putting some <![CDATA[ cdata markers right ]]> in here!!
You would want the resultant output to look something like this:
<![CDATA[I am purposefully putting some <![CDATA[ cdata markers right ]]]]><![CDATA[> in here!!]]>
The following implementation will loop over the string, split up instances of ...]]>... into ...]] and >... and create separate CDATA sections for each.
[XmlRoot("root")]
public class Sample1Xml
{
internal Sample1Xml()
{
}
[XmlElement("node")]
public NodeType Node { get; set; }
#region Nested type: NodeType
public class NodeType
{
[XmlAttribute("attr1")]
public string Attr1 { get; set; }
[XmlAttribute("attr2")]
public string Attr2 { get; set; }
[XmlIgnore]
public string Content { get; set; }
[XmlText]
public XmlNode[] CDataContent
{
get
{
XmlDocument dummy = new XmlDocument();
List<XmlNode> xmlNodes = new List<XmlNode>();
int tokenCount = 0;
int prevSplit = 0;
for (int i = 0; i < Content.Length; i++)
{
char c = Content[i];
//If the current character is > and it was preceded by ]] (i.e. the last 3 characters were ]]>)
if (c == '>' && tokenCount >= 2)
{
//Put everything up to this point in a new CData Section
string thisSection = Content.Substring(prevSplit, i - prevSplit);
xmlNodes.Add(dummy.CreateCDataSection(thisSection));
prevSplit = i;
}
if (c == ']')
{
tokenCount++;
}
else
{
tokenCount = 0;
}
}
//Put the final part of the string into a CData section
string finalSection = Content.Substring(prevSplit, Content.Length - prevSplit);
xmlNodes.Add(dummy.CreateCDataSection(finalSection));
return xmlNodes.ToArray();
}
set
{
if (value == null)
{
Content = null;
return;
}
if (value.Length != 1)
{
throw new InvalidOperationException(
String.Format(
"Invalid array length {0}", value.Length));
}
Content = value[0].Value;
}
}
}
This works pretty well
using System.Collections.ObjectModel;
using System.Linq;
using System.Xml;
using System.Xml.Serialization;
public class CDataContent
{
public CDataContent()
{
}
public CDataContent(string content)
{
this.Content = content;
}
[XmlIgnore]
public string Content
{
get => this.CData.FirstOrDefault()?.Value;
set
{
this.CData.Clear();
this.CData.Add(new XmlDocument().CreateCDataSection(value));
}
}
[XmlText]
public Collection<XmlNode> CData { get; } = new();
public static implicit operator CDataContent(string value) => new(value);
public static implicit operator string(CDataContent value) => value.Content;
}

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