Fix references from transient nodes to persistent ones in Xml.read() and Xml.write().

* In XmlWriter generate reference tags when referencing a persistent node from a
   transient one.
* In XmlReader make sure we have the app's NodeManager to look up node
   references we don't know about.
Fixes bug 371: http://helma.org/bugs/show_bug.cgi?id=371

src/helma/objectmodel/dom/XmlReader.java

@@ -17,6 +17,7 @@
 package helma.objectmodel.dom;
 
 import helma.objectmodel.INode;
+import helma.objectmodel.db.WrappedNodeManager;
 import org.xml.sax.Attributes;
 import org.xml.sax.InputSource;
 import org.xml.sax.SAXException;
@@ -45,11 +46,13 @@ public final class XmlReader extends DefaultHandler implements XmlConstants {
     private String elementName = null;
     private StringBuffer charBuffer = null;
     boolean parsingHopObject;
+    WrappedNodeManager nmgr;
 
     /**
      * Creates a new XmlReader object.
      */
-    public XmlReader() {
+    public XmlReader(WrappedNodeManager nmgr) {
+        this.nmgr = nmgr;
     }
 
     /**
@@ -190,6 +193,12 @@ public final class XmlReader extends DefaultHandler implements XmlConstants {
             String key = idref + "-" + prototyperef;
             INode n = (INode) convertedNodes.get(key);
 
+            // if not a reference to a node we already read, try to
+            // resolve against the NodeManager.
+            if (n == null) {
+                n = nmgr.getNode(idref, nmgr.getDbMapping(prototyperef));
+            }
+
             if (n != null) {
                 if ("hop:child".equals(qName)) {
                     // add an already parsed node as child to current node

src/helma/objectmodel/dom/XmlWriter.java

@@ -20,6 +20,7 @@ package helma.objectmodel.dom;
 import helma.objectmodel.INode;
 import helma.objectmodel.IProperty;
 import helma.objectmodel.TransientNode;
+import helma.objectmodel.INodeState;
 import helma.objectmodel.db.DbMapping;
 import helma.objectmodel.db.Node;
 import helma.util.HtmlEncoder;
@@ -43,7 +44,10 @@ public class XmlWriter extends OutputStreamWriter implements XmlConstants {
     private SimpleDateFormat format = new SimpleDateFormat(DATEFORMAT);
     private boolean dbmode = true;
 
-    // Only add encoding to XML declaration if it was explicitly set, not when we're using 
+    // the helma.objectmodel.INodeState of the node we're writing
+    public int rootState;
+
+    // Only add encoding to XML declaration if it was explicitly set, not when we're using
     // the platform's standard encoding.
     private String explicitEncoding;
 
@@ -182,6 +186,7 @@ public class XmlWriter extends OutputStreamWriter implements XmlConstants {
      * the cache of already converted nodes.
      */
     public boolean write(INode node) throws IOException {
+        rootState = node.getState();
         convertedNodes = new Vector();
 
         if (explicitEncoding == null) {
@@ -228,6 +233,13 @@ public class XmlWriter extends OutputStreamWriter implements XmlConstants {
 
         if (convertedNodes.contains(node)) {
             writeReferenceTag(node, elementName, propName);
+        } else if (rootState == INodeState.TRANSIENT &&
+                   node.getState() > INodeState.TRANSIENT) {
+            // if we are writing a transient node, and that node
+            // holds a reference to a persistent one, just write a
+            // reference tag to that persistent node.
+            writeReferenceTag(node, elementName, propName);
+
         } else {
             convertedNodes.addElement(node);
             writeTagOpen(node, elementName, propName);

src/helma/scripting/rhino/extensions/XmlObject.java

@@ -141,7 +141,7 @@ public class XmlObject {
         }
 
         try {
-            XmlReader reader = new XmlReader();
+            XmlReader reader = new XmlReader(core.app.getWrappedNodeManager());
             INode result = reader.read(new File(file), node);
 
             return core.getNodeWrapper(result);
@@ -188,7 +188,7 @@ public class XmlObject {
         }
 
         try {
-            XmlReader reader = new XmlReader();
+            XmlReader reader = new XmlReader(core.app.getWrappedNodeManager());
             INode result = reader.read(new StringReader(str), node);
 
             return core.getNodeWrapper(result);