/// <summary>
/// Generates the OWL graph into an XmlDocument object
/// </summary>
/// <param name="graph">The graph which needs to be generated</param>
/// <param name="doc">The XmlDocument object used as a destination for the graph</param>
public void GenerateOwl(IOwlGraph graph, XmlDocument doc)
{
if (doc == null)
{
throw (new ArgumentNullException("The specified XmlDocument object is a null reference"));
}
Warnings.Clear();
Errors.Clear();
_visited.Clear();
XmlElement root = _owlDocument.CreateElement("rdf:RDF", OwlNamespaceCollection.RdfNamespace);
_owlDocument.AppendChild(root);
//Added by HM
// Create an XML declaration.
XmlDeclaration xmldecl = _owlDocument.CreateXmlDeclaration("1.0", null, null);
xmldecl.Encoding = "UTF-8";
xmldecl.Standalone = "yes";
// Add the new node to the document.
_owlDocument.InsertBefore(xmldecl, root);
//End of HM addition
_baseUri = graph.NameSpaces["xml:base"];
IDictionaryEnumerator nsEnumerator = (IDictionaryEnumerator)graph.NameSpaces.GetEnumerator();
while (nsEnumerator.MoveNext())
{
// Write all the namespaces to the document
XmlAttribute nsAttribute = _owlDocument.CreateAttribute((nsEnumerator.Key).ToString());
nsAttribute.Value = (nsEnumerator.Value).ToString();
root.Attributes.Append(nsAttribute);
// Also insert the reversed namespaces into the a local variable
_namespaces[nsEnumerator.Value.ToString()] = nsEnumerator.Key.ToString();
}
IDictionaryEnumerator nEnumerator = (IDictionaryEnumerator)graph.Nodes.GetEnumerator();
while (nEnumerator.MoveNext())
{
OwlNode node = (OwlNode)graph.Nodes[(nEnumerator.Key).ToString()];
if (!node.IsAnonymous())
{
node.Accept(this, root);
}
}
XmlComment comment = _owlDocument.CreateComment("This file has been generated by the OwlDotNetApi.");
_owlDocument.AppendChild(comment);
doc = _owlDocument;
}
/// <summary>
/// The general implementation of a regular OwlNode. A node is only of type OwlNode in some special cases.
/// </summary>
/// <param name="node">The actual node to visit</param>
/// <param name="parent">The parent object of the node</param>
public override void Visit(OwlNode node, Object parent)
{
XmlElement parentElement = parent as XmlElement;
if (parentElement != null)
{
// Here we will only visit the blank node, because these are
// the only ones we need. The others are the standard nodes
// representing datatypes or owl, rdf, rdfs predefined nodes.
if (node.IsAnonymous())
{
XmlComment comment = _owlDocument.CreateComment("Visiting a regular node: " + node.GetType());
parentElement.AppendChild(comment);
_visited.Add(node);
}
}
}
/// <summary>
/// The general implementation of a regular OwlNode. A node is only of type OwlNode in some special cases.
/// </summary>
/// <param name="node">The actual node to visit</param>
/// <param name="parent">The parent object of the node</param>
public override void Visit(OwlNode node, Object parent)
{
XmlElement parentElement = parent as XmlElement;
if(parentElement != null)
{
// Here we will only visit the blank node, because these are
// the only ones we need. The others are the standard nodes
// representing datatypes or owl, rdf, rdfs predefined nodes.
if(node.IsAnonymous())
{
XmlComment comment = _owlDocument.CreateComment("Visiting a regular node: " + node.GetType());
parentElement.AppendChild(comment);
node.Visited = true;
}
}
}
/// <summary>
/// Implementation of an OwlEdge.
/// </summary>
/// <param name="edge">The actual edge to be visited</param>
/// <param name="parent">The parent object (node) of the edge</param>
public override void Visit(OwlEdge edge, Object parent)
{
XmlElement parentElement = parent as XmlElement;
if (parentElement != null)
{
Uri uri = new Uri(edge.ID);
// Retrieve the local name from the uri
string localName = uri.Fragment.Substring(1, uri.Fragment.Length - 1);
// Get the path, up to the local name, from the uri
string path = uri.GetLeftPart(UriPartial.Path) + "#";
string prefix;
// Check for the namespace of the edge in order to get the correct prefix
if (path == OwlNamespaceCollection.OwlNamespace)
{
prefix = OwlNamespaceCollection.OwlNamespacePrefix;
}
else if (path == OwlNamespaceCollection.RdfNamespace)
{
prefix = OwlNamespaceCollection.RdfNamespacePrefix;
}
else if (path == OwlNamespaceCollection.RdfSchemaNamespace)
{
prefix = OwlNamespaceCollection.RdfSchemaNamespacePrefix;
}
else
{
// If the namespace of the edge is something else, then look for it
prefix = "";
if (path != _baseUri)
{
// Search for the prefix of this individual
int pos = _namespaces[path].IndexOf(':');
if (pos != -1)
{
prefix = _namespaces[path].Substring(++pos);
}
}
}
string qualifiedName = (prefix.Length != 0) ? (prefix + ":" + localName) : localName;
// At this point we will not generate the rdf:type edges.
XmlElement edgeElement = _owlDocument.CreateElement(qualifiedName, path);
// Check to see if the child node is an anonymous one or not. If it is, then further
// process that node, otherwise just reference it by name.
OwlNode node = (OwlNode)edge.ChildNode;
if (node.IsAnonymous() || node.IsLiteral())
{
node.Accept(this, edgeElement);
}
else
{
// Add the name as one of its attributes
XmlAttribute nameAttribute = _owlDocument.CreateAttribute("rdf", "resource", OwlNamespaceCollection.RdfNamespace);
nameAttribute.Value = GetNodeReference(node);
edgeElement.Attributes.Append(nameAttribute);
}
parentElement.AppendChild(edgeElement);
}
}
