// Conversion of an XML-structure (in a string or in a file) to a Prolog BaseTerm
public static BaseTerm XmlToTerm(BaseTerm settings, string s, bool inFile)
{
XmlTextReader xrd = null;
StreamReader sr = null;
Encoding encoding = GetEncodingFromString ("UTF-8");
Node result;
string settingValue = null;
// get settings -- currently, only 'encoding' is recognized
if (settings != null)
foreach (BaseTerm setting in (ListTerm)settings) // traverse ...
{
string settingName = setting.FunctorToString;
if (setting.Arity == 1)
settingValue = setting.Arg (0).FunctorToString;
else
IO.Error ("Illegal setting in xml_term/3: '{0}'", setting);
switch (settingName)
{
// Expected string or file encoding. Superseded by explicit encoding attribute setting found in xml
case "encoding":
encoding = GetEncodingFromString (settingValue); // default is UTF-8
break;
default:
IO.Error ("Unknown setting in xml_term/3: '{0}'", setting);
break;
}
}
try
{
if (inFile)
{
sr = new StreamReader (s, encoding);
xrd = new XmlTextReader (sr);
}
else
xrd = new XmlTextReader (new StringReader (s));
//xrd.ProhibitDtd = true; // new in the .NET Framework version 2.0
xrd.Namespaces = false;
result = new Node ();
result.TagName = "<root>";
result.type = XmlNodeType.Element;
result.ToNode (xrd, 0); // first, create an intermediate representation (a Node) containing the XML structure
}
catch (Exception e)
{
string source = inFile ? string.Format (" file '{0}'", s) : null;
throw new ApplicationException (
string.Format ("Error in XML input{0}. Message was:\r\n{1}", source, e.Message));
}
finally
{
if (sr != null) sr.Close ();
if (xrd != null) xrd.Close ();
}
return result.ToTerm (); // Convert the Node to a Prolog BaseTerm
}
public void ToNode(XmlTextReader reader, int level)
{
Node child; // essentially: in the loop, add new nodes to this.childNodes
while (reader.Read ())
{
//IO.WriteLine ("Read name={0} value={1} reader.NodeType={2} Level={3}", reader.Name, reader.Value.Trim (), reader.NodeType, level);
switch (reader.NodeType)
{
case XmlNodeType.Element: // create a new subelement
bool isEmpty = reader.IsEmptyElement;
child = new Node ();
child.type = XmlNodeType.Element;
child.name = reader.LocalName;
child.text = reader.Prefix;
while (reader.MoveToNextAttribute ())
child.AddAttribute (reader.Name, reader.Value);
if (isEmpty)
{
childNodes.Insert (0, child);
continue;
}
child.ToNode (reader, level + 1);
childNodes.Insert (0, child);
break;
case XmlNodeType.Attribute:
this.AddAttribute (reader.Name, reader.Value);
break;
case XmlNodeType.EndElement:
return;
case XmlNodeType.Comment:
case XmlNodeType.Text:
case XmlNodeType.CDATA:
child = new Node ();
child.type = reader.NodeType;
child.Text = reader.Value;
childNodes.Insert (0, child);
break;
case XmlNodeType.ProcessingInstruction:
child = new Node ();
child.type = reader.NodeType;
child.name = reader.Name;
child.text = reader.Value;
childNodes.Insert (0, child);
break;
case XmlNodeType.XmlDeclaration:
while (reader.MoveToNextAttribute ())
this.AddAttribute (reader.Name, reader.Value);
break;
case XmlNodeType.Document:
case XmlNodeType.DocumentFragment:
case XmlNodeType.DocumentType:
case XmlNodeType.EndEntity:
case XmlNodeType.Entity:
case XmlNodeType.EntityReference:
case XmlNodeType.None:
case XmlNodeType.Notation:
case XmlNodeType.SignificantWhitespace:
case XmlNodeType.Whitespace:
// ignore
break;
default:
throw new ApplicationException (
string.Format ("*** Unhandled XmlTextReader.NodeType: {0}", reader.NodeType));
}
}
return;
}
/// Conversion of an XML-structure (in a string or in a file) to a Prolog Term
public static Term XmlToTerm(string s, bool inFile)
{
XmlTextReader xrd;
if (inFile)
xrd = new XmlTextReader(s);
else
xrd = new XmlTextReader(new StringReader(s));
//xrd.ProhibitDtd = true; // new in the .NET Framework version 2.0
Node result = new Node();
result.TagName = "<root>";
result.type = XmlNodeType.Element;
try
{
result.ToNode(xrd, 0); // first, create an intermediate representation (a Node) containing the XML structure
}
finally
{
xrd.Close();
}
return result.ToTerm(); // Convert the Node to a Prolog Term
}