[graphl-cvs] graphl/src/org/mediavirus/graphl/jaxen IterableGraphlAxis.java GraphlXPath.java DocumentNavigator.java GuessNamespaceFunction.java GuessNameFunction.java

[Flo L. <fl...@us...>]

Update of /cvsroot/graphl/graphl/src/org/mediavirus/graphl/jaxen
In directory sc8-pr-cvs2.sourceforge.net:/tmp/cvs-serv11488/src/org/mediavirus/graphl/jaxen

Added Files:
	IterableGraphlAxis.java GraphlXPath.java 
	DocumentNavigator.java GuessNamespaceFunction.java 
	GuessNameFunction.java 
Log Message:
- migrated from jxpath to jaxen, which gives a much cleaner implementation of custom axes


--- NEW FILE: DocumentNavigator.java ---
/*
 * Created on 26.06.2006
 */

package org.mediavirus.graphl.jaxen;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.jaxen.DefaultNavigator;
import org.jaxen.NamedAccessNavigator;
import org.jaxen.Navigator;
import org.jaxen.UnsupportedAxisException;
import org.jaxen.XPath;
import org.jaxen.saxpath.Axis;
import org.jaxen.saxpath.SAXPathException;
import org.mediavirus.graphl.graph.Edge;
import org.mediavirus.graphl.graph.GraphElement;
import org.mediavirus.graphl.graph.Node;


public class DocumentNavigator extends DefaultNavigator implements NamedAccessNavigator {

    /** Singleton implementation.
     */
    private static class Singleton
    {
        /** Singleton instance.
         */
        private static DocumentNavigator instance = new DocumentNavigator();
    }

    /** Retrieve the singleton instance of this <code>DocumentNavigator</code>.
     */
    public static Navigator getInstance()
    {
        return Singleton.instance;
    }

    public Iterator getChildAxisIterator(Object contextNode, String localName, String namespacePrefix, String namespaceURI) throws UnsupportedAxisException {
        return null;
    }

    public Iterator getAttributeAxisIterator(Object contextNode, String localName, String namespacePrefix, String namespaceURI) throws UnsupportedAxisException {
        
//        System.out.println("Attrib Iterator: ");
//        System.out.println("               : context: " + contextNode);
//        System.out.println("               : locName: " + localName);
//        System.out.println("               : nsPref.: " + namespacePrefix);
//        System.out.println("               : nsURI  : " + namespaceURI);

        if (contextNode instanceof GraphElement) {
            GraphElement element = (GraphElement)contextNode;
            if (localName != null) {
                return Collections.singleton(element.getProperty(namespaceURI + localName)).iterator();
            }
            else {
                return element.getProperties().values().iterator();
            }
        }
        return null;
    }

    public String getElementNamespaceUri(Object element) {
        return null;
    }

    public String getElementName(Object element) {
        return null;
    }

    public String getElementQName(Object element) {
        return null;
    }

    public String getAttributeNamespaceUri(Object attr) {
        return null;
    }

    public String getAttributeName(Object attr) {
        return null;
    }

    public String getAttributeQName(Object attr) {
        return null;
    }

    public boolean isDocument(Object object) {
        return false;
    }

    public boolean isElement(Object object) {
        return (object instanceof GraphElement);
    }

    public boolean isAttribute(Object object) {
        return (object instanceof String);
    }

    public boolean isNamespace(Object object) {
        return false;
    }

    public boolean isComment(Object object) {
        return false;
    }

    public boolean isText(Object object) {
        return false;
    }

    public boolean isProcessingInstruction(Object object) {
        return false;
    }

    public String getCommentStringValue(Object comment) {
        return null;
    }

    public String getElementStringValue(Object element) {
        return ((GraphElement)element).getId();
    }

    public String getAttributeStringValue(Object attr) {
        return (String)attr;
    }

    public String getNamespaceStringValue(Object ns) {
        return null;
    }

    public String getTextStringValue(Object text) {
        return null;
    }

    public String getNamespacePrefix(Object ns) {
        return null;
    }

    public XPath parseXPath(String xpath) throws SAXPathException {
        return new GraphlXPath(xpath);
    }

    public Iterator getGraphlAxisIterator(int axis, Object contextNode, String localName, String namespacePrefix, String namespaceURI) {
//        System.out.println("Axis Iterator: " + Axis.lookup(axis));
//        System.out.println("             : context: " + contextNode);
//        System.out.println("             : locName: " + localName);
//        System.out.println("             : nsPref.: " + namespacePrefix);
//        System.out.println("             : nsURI  : " + namespaceURI);
        
        List<GraphElement> matchingElements = new ArrayList<GraphElement>();
        if (contextNode instanceof Node) {
            Node node = (Node)contextNode;
            if (axis == Axis.BOTH || axis == Axis.OUT) {
                if (localName != null) {
                    matchingElements.addAll(node.getEdgesFrom(namespaceURI + localName));
                }
                else {
                    matchingElements.addAll(node.getEdgesFrom());
                }
            }
            if (axis == Axis.BOTH || axis == Axis.IN) {
                if (localName != null) {
                    matchingElements.addAll(node.getEdgesTo(namespaceURI + localName));
                }
                else {
                    matchingElements.addAll(node.getEdgesTo());
                }
            }
        }
        else if (contextNode instanceof Edge) {
            Edge edge = (Edge)contextNode;
            if (axis == Axis.BOTH || axis == Axis.OUT) {
                if (localName != null) {
                    Node n = edge.getTo();
                    if (n.getType().equals(namespaceURI + localName)) {
                        matchingElements.add(n);
                    }
                }
                else {
                    matchingElements.add(edge.getTo());
                }                
            }
            if (axis == Axis.BOTH || axis == Axis.IN) {
                if (localName != null) {
                    Node n = edge.getFrom();
                    if (n.getType().equals(namespaceURI + localName)) {
                        matchingElements.add(n);
                    }
                }
                else {
                    matchingElements.add(edge.getFrom());
                }
            }
        }
        return matchingElements.iterator();
    }
}

--- NEW FILE: GraphlXPath.java ---
/*
 * Created on 26.06.2006
 */

package org.mediavirus.graphl.jaxen;

import org.jaxen.BaseXPath;
import org.jaxen.JaxenException;
import org.jaxen.SimpleFunctionContext;
import org.jaxen.SimpleNamespaceContext;
import org.jaxen.XPathFunctionContext;
import org.mediavirus.graphl.GraphlRegistry;


public class GraphlXPath extends BaseXPath {

    public GraphlXPath(String xpathExpr) throws JaxenException
    {
        super( xpathExpr, DocumentNavigator.getInstance() );

        SimpleFunctionContext fc = new XPathFunctionContext();
        fc.registerFunction("http://www.mediavirus.org/graphl#", "guessName", new GuessNameFunction());
        fc.registerFunction("http://www.mediavirus.org/graphl#", "guessNamespace", new GuessNamespaceFunction());
        this.setFunctionContext(fc);
        
        this.setNamespaceContext(GraphlRegistry.instance().getVocabularyRegistry());
    }

}

--- NEW FILE: GuessNameFunction.java ---
/*
 * Created on 27.06.2006
 */

package org.mediavirus.graphl.jaxen;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.jaxen.Context;
import org.jaxen.Function;
import org.jaxen.FunctionCallException;
import org.jaxen.Navigator;
import org.jaxen.function.StringFunction;
import org.mediavirus.util.ParseUtils;


public class GuessNameFunction implements Function{

    public List<String> call(Context context, List args) throws FunctionCallException {
        
        List<String> result = new ArrayList<String>();
        if (args.isEmpty()) return result;
        
        Navigator navigator = context.getNavigator();
        Iterator iterator = args.iterator();
        while (iterator.hasNext()) {
            String next = StringFunction.evaluate(iterator.next(), navigator);
            result.add(ParseUtils.guessName(next));
        }
        return result;
    }

    
}

--- NEW FILE: GuessNamespaceFunction.java ---
/*
 * Created on 27.06.2006
 */

package org.mediavirus.graphl.jaxen;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.jaxen.Context;
import org.jaxen.Function;
import org.jaxen.FunctionCallException;
import org.jaxen.Navigator;
import org.jaxen.function.StringFunction;
import org.mediavirus.util.ParseUtils;


public class GuessNamespaceFunction implements Function {

    public List<String> call(Context context, List args) throws FunctionCallException {
        
        List<String> result = new ArrayList<String>();
        if (args.isEmpty()) return result;
        
        Navigator navigator = context.getNavigator();
        Iterator iterator = args.iterator();
        while (iterator.hasNext()) {
            String next = StringFunction.evaluate(iterator.next(), navigator);
            result.add(ParseUtils.guessNamespace(next));
        }
        return result;
    }

}

--- NEW FILE: IterableGraphlAxis.java ---
/*
 * Created on 26.06.2006
 */

package org.mediavirus.graphl.jaxen;

import java.util.Iterator;

import org.jaxen.ContextSupport;
import org.jaxen.NamedAccessNavigator;
import org.jaxen.UnsupportedAxisException;
import org.jaxen.expr.iter.IterableAxis;


public class IterableGraphlAxis extends IterableAxis {

    int value;
    
    public IterableGraphlAxis(int axisValue) {
        super(axisValue);
        this.value = axisValue;
    }

    @Override
    public Iterator iterator(Object contextNode, ContextSupport support) throws UnsupportedAxisException {
        if (support.getNavigator() instanceof DocumentNavigator) {
            DocumentNavigator nav = (DocumentNavigator)support.getNavigator();
            return nav.getGraphlAxisIterator(this.value, contextNode, null, null, null);
        }
        return null;
    }

    /**
     * Gets an iterator for the child XPath axis that supports named access.
     * 
     * @param contextNode  the current context node to work from
     * @param support  the additional context information
     * @param localName  the local name of the children to return
     * @param namespacePrefix  the prefix of the namespace of the children to return
     * @param namespaceURI  the URI of the namespace of the children to return
     * @return an iterator over the children of the context node
     * @throws UnsupportedAxisException if the child axis is not supported by the model
     */
    public Iterator namedAccessIterator(
        Object contextNode,
        ContextSupport support,
        String localName,
        String namespacePrefix,
        String namespaceURI)
            throws UnsupportedAxisException {
                
        if (support.getNavigator() instanceof DocumentNavigator) {
            DocumentNavigator nav = (DocumentNavigator)support.getNavigator();
            return nav.getGraphlAxisIterator(this.value, contextNode, localName, namespacePrefix, namespaceURI);
        }
        return null;
    }
    
    /**
     * Does this axis support named access?
     * 
     * @param support the additional context information
     * @return true if named access supported. If not iterator() will be used
     */
    public boolean supportsNamedAccess(ContextSupport support) {
        return (support.getNavigator() instanceof NamedAccessNavigator);
    }

}