How to write XML with any name and type?

[Guest]

Disappointed, this is not the first time I'm posting this kind of a request
for help, but no helpful answer was posted yet.

I'll try make my question as clear as I can:

(1) I wish to write an XML file. this file will contain any number of
parameters to be used in my C# code as database.
(2) This file may contain any number of parameters, and I will know the
number of the parameters only at run time.
(3) Any parameter must have a name, but this name may be any name, and I
will know the names of the parameters only at run time.
(4) Any parameter must have a type, this type can be of any well known type
(int, string, float, dateTime, byte etc.), and I will know these types only
at run time.
(5) Any parameter may or may not have several more attributes
(authorization, precision, range), I will now if any of this attributes exist
only at run time.
(6) Any parameter will have a value of the type as described above.

I need to read this parameters form the XML file as their real value without
doing any code switching, and to assign these values to my run time data
members.

I thought I'll be able to load the XML file into DataSet and read the
parameters from it. But I'll be happy to use any other solution you may have.

 

[Bill B]

One option would be to:

1. Create a class that implements the ISerializable interface
2. Serialize the class to XML (sample code below)
3. Deserialize the class from the XML back into a class (no code sample
on that one - sorry)

Sample Code

using System.Xml.Serialization;
using System.IO;

protected string SerializeObjectToString(object data)
{
if (data == null)
return string.Empty;

if (data.GetType().Name == "String")
return (string)data;
else
{
XmlSerializer mySerializer = new
XmlSerializer(data.GetType());

StringWriter myWriter = new StringWriter();
mySerializer.Serialize(myWriter, data);
string ret = myWriter.ToString();

myWriter.Close();

return ret;
}
}

Bill

 

[Bill Block]

One option would be to:

1. Create a class that implements the ISerializable interface
2. Serialize the class to XML (sample code below)
3. Deserialize the class from the XML back into a class (no code sample
on that one - sorry)

Sample Code

using System.Xml.Serialization;
using System.IO;

protected string SerializeObjectToString(object data)
{
if (data == null)
return string.Empty;

if (data.GetType().Name == "String")
return (string)data;
else
{
XmlSerializer mySerializer = new
XmlSerializer(data.GetType());

StringWriter myWriter = new StringWriter();
mySerializer.Serialize(myWriter, data);
string ret = myWriter.ToString();

myWriter.Close();

return ret;
}
}

Bill

 

[Guest]

Thanks Bill for you replay.

I'm not sure I understand how the serialization and deserialization can
solve my problem.

The XML file may contain any tree structure the user wishes, and I will now
this tree on at run time.

So, at run time, I need to reed the entire parameters from the XML, and
while reading I need to reed the parameters value without doing any code
switching and casting. I want to read the value in the correct type.

Can you please explain if and how your suggestion of serialize and
deserialize can do all of that?

 

[Bill Block]

Do you know the full list of possible parameters up front? If so, you
could build a serializable "parameters" class that contains a value for
all of the parameters. As you read the XML you could populate the
appropriate parameter (and have it strongly-typed).

i.e.

[ISerializable]
public class MyParameters
{
public int Property1 { get; set; }

public string Property2 {get; set; }
}

If you don't know the full list of possible parameters beforehand, how
are you validating the incoming XML - is there an XSD? If so, you
could use the xsd.exe included in the .NET tools to create a class for
that schema that can directly read in the XML. This would allow you to
manipulate the XML in code. For more info see:
http://msdn.microsoft.com/library/d...s/html/cpconxmlschemadefinitiontoolxsdexe.asp.

Bill

 

[Guest]

No, sorry, I do not know full list of possible parameters up front.

And I can not use XSD, because the the XSD schema need to now beforehand the
tree structure and parameters names and types, which I do not. Only at run
time I now all of that.

 

[Guest]

Ok, I think I found a way to do thanks to Marc Clifton articale on
CodeProject (http://www.codeproject.com/dotnet/MycroXaml.asp).

The XML file can be somthing like that:

<?xml version="1.0" encoding="utf-8"?>
<System Name="System">
<Paramaters>
<Speed type="System.Iint32">111</Speed >
<_xAxis type="System.Single">222</_xAxis>
<_yAxis type="System.Double">333</_yAxis>
<_ID type="System.Int64">444</_ID>
<_Name type="System.String">String value...</_Name>
</Paramaters>
</System>


And the C# code can be:

System.IO.StreamReader sr = new System.IO.StreamReader("TypesDef.xml");
string text = sr.ReadToEnd();
sr.Close();
XmlDocument doc = new XmlDocument();
doc.LoadXml(text);
XmlNode node = doc.FirstChild;
while( node.NodeType.ToString() != "Element" )
{
node = node.NextSibling;
}

XmlNode paramsNode = doc.SelectSingleNode("//Paramaters");
XmlNodeList nodeList = paramsNode.ChildNodes;
Hashtable verTypes = new Hashtable(nodeList.Count);
string typeName = "";
Type type;

foreach( XmlNode xmlNode in nodeList )
{
XmlAttribute attr = xmlNode.Attributes["type"];
typeName = attr.Value;
if( typeName == "System.String" )
{
verTypes[xmlNode.Name] = xmlNode.InnerText;
}
else
{
type = Type.GetType(typeName, false);
object typeIntance = Activator.CreateInstance(type);
System.Reflection.MethodInfo Parse = type.GetMethod("Parse", new Type
[] {typeof(String)});
verTypes[xmlNode.Name] = Parse.Invoke(type, new object[]
{xmlNode.InnerText});
}
}