package org.exist.xupdate;
import java.util.Map;
import org.exist.EXistException;
import org.exist.collections.triggers.TriggerException;
import org.exist.dom.AttrImpl;
import org.exist.dom.DocumentImpl;
import org.exist.dom.DocumentSet;
import org.exist.dom.ElementImpl;
import org.exist.dom.StoredNode;
import org.exist.dom.TextImpl;
import org.exist.security.Permission;
import org.exist.security.PermissionDeniedException;
import org.exist.storage.DBBroker;
import org.exist.storage.NotificationService;
import org.exist.storage.UpdateListener;
import org.exist.storage.txn.Txn;
import org.exist.util.LockException;
import org.exist.xquery.XPathException;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* Implements xupdate:replace, an extension to the XUpdate standard.
* The modification replaces a node and its contents. It differs from xupdate:update
* which only replaces the contents of the node, not the node itself.
*
* @author wolf
*/
public class Replace extends Modification {
/**
* @param broker
* @param docs
* @param selectStmt
* @param namespaces
* @param variables
*/
public Replace(DBBroker broker, DocumentSet docs, String selectStmt,
Map<String, String> namespaces, Map<String, Object> variables) {
super(broker, docs, selectStmt, namespaces, variables);
}
/* (non-Javadoc)
* @see org.exist.xupdate.Modification#process()
*/
public long process(Txn transaction) throws PermissionDeniedException, LockException,
EXistException, XPathException, TriggerException {
final NodeList children = content;
if (children.getLength() == 0)
{return 0;}
if (children.getLength() > 1)
{throw new EXistException("xupdate:replace requires exactly one content node");}
LOG.debug("processing replace ...");
int modifications = children.getLength();
try {
final StoredNode ql[] = selectAndLock(transaction);
final IndexListener listener = new IndexListener(ql);
final NotificationService notifier = broker.getBrokerPool().getNotificationService();
Node temp;
TextImpl text;
AttrImpl attribute;
ElementImpl parent;
for (int i = 0; i < ql.length; i++) {
final StoredNode node = ql[i];
if (node == null) {
LOG.warn("select " + selectStmt + " returned empty node set");
continue;
}
final DocumentImpl doc = (DocumentImpl)node.getOwnerDocument();
doc.getMetadata().setIndexListener(listener);
if (!doc.getPermissions().validate(broker.getSubject(), Permission.WRITE)) {
throw new PermissionDeniedException("User '" + broker.getSubject().getName() + "' does not have permission to write to the document '" + doc.getDocumentURI() + "'!");
}
parent = (ElementImpl) node.getParentStoredNode();
if (parent == null)
{throw new EXistException("The root element of a document can not be replaced with 'xu:replace'. " +
"Please consider removing the document or use 'xu:update' to just replace the children of the root.");}
switch (node.getNodeType()) {
case Node.ELEMENT_NODE:
if (modifications == 0) {modifications = 1;}
temp = children.item(0);
parent.replaceChild(transaction, temp, node);
break;
case Node.TEXT_NODE:
temp = children.item(0);
text = new TextImpl(temp.getNodeValue());
modifications = 1;
text.setOwnerDocument(doc);
parent.updateChild(transaction, node, text);
break;
case Node.ATTRIBUTE_NODE:
final AttrImpl attr = (AttrImpl) node;
temp = children.item(0);
attribute = new AttrImpl(attr.getQName(), temp.getNodeValue(), broker.getBrokerPool().getSymbols());
attribute.setOwnerDocument(doc);
parent.updateChild(transaction, node, attribute);
break;
default:
throw new EXistException("unsupported node-type");
}
doc.getMetadata().clearIndexListener();
doc.getMetadata().setLastModified(System.currentTimeMillis());
modifiedDocuments.add(doc);
broker.storeXMLResource(transaction, doc);
notifier.notifyUpdate(doc, UpdateListener.UPDATE);
}
checkFragmentation(transaction, modifiedDocuments);
} finally {
unlockDocuments(transaction);
}
return modifications;
}
/* (non-Javadoc)
* @see org.exist.xupdate.Modification#getName()
*/
public String getName() {
return XUpdateProcessor.REPLACE;
}
}