/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2010 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* $Id$
*/
package org.exist.xquery.update;
import org.exist.EXistException;
import org.exist.collections.triggers.TriggerException;
import org.exist.dom.DocumentImpl;
import org.exist.dom.NodeImpl;
import org.exist.dom.StoredNode;
import org.exist.security.Permission;
import org.exist.security.PermissionDeniedException;
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.Dependency;
import org.exist.xquery.Expression;
import org.exist.xquery.Profiler;
import org.exist.xquery.XPathException;
import org.exist.xquery.XPathUtil;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.util.Error;
import org.exist.xquery.util.ExpressionDumper;
import org.exist.xquery.util.Messages;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;
import org.exist.xquery.value.ValueSequence;
import org.w3c.dom.Node;
/**
* @author wolf
*
*/
//TODO: this is the only update function that uses transaction.abort() do we really need to use it and if so shouldnt the others use it as well?!?
public class Delete extends Modification {
/**
*
*
* @param context
* @param select
*/
public Delete(XQueryContext context, Expression select) {
super(context, select, null);
}
/* (non-Javadoc)
* @see org.exist.xquery.AbstractExpression#eval(org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
*/
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);}
if (contextItem != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());}
}
if (contextItem != null)
{contextSequence = contextItem.toSequence();}
final Sequence inSeq = select.eval(contextSequence);
//START trap Delete failure
/* If we try and Delete a node at an invalid location,
* trap the error in a context variable,
* this is then accessible from xquery via. the context extension module - deliriumsky
* TODO: This trapping could be expanded further - basically where XPathException is thrown from thiss class
* TODO: Maybe we could provide more detailed messages in the trap, e.g. couldnt delete node `xyz` into `abc` becuase... this would be nicer for the end user of the xquery application
*/
if (!Type.subTypeOf(inSeq.getItemType(), Type.NODE))
{
//Indicate the failure to perform this update by adding it to the sequence in the context variable XQueryContext.XQUERY_CONTEXTVAR_XQUERY_UPDATE_ERROR
ValueSequence prevUpdateErrors = null;
final XPathException xpe = new XPathException(this, Messages.getMessage(Error.UPDATE_SELECT_TYPE));
final Object ctxVarObj = context.getXQueryContextVar(XQueryContext.XQUERY_CONTEXTVAR_XQUERY_UPDATE_ERROR);
if(ctxVarObj == null)
{
prevUpdateErrors = new ValueSequence();
}
else
{
prevUpdateErrors = (ValueSequence)XPathUtil.javaObjectToXPath(ctxVarObj, context);
}
prevUpdateErrors.add(new StringValue(xpe.getMessage()));
context.setXQueryContextVar(XQueryContext.XQUERY_CONTEXTVAR_XQUERY_UPDATE_ERROR, prevUpdateErrors);
if(!inSeq.isEmpty())
{throw xpe;} //TODO: should we trap this instead of throwing an exception - deliriumsky?
}
//END trap Delete failure
if (!inSeq.isEmpty()) {
//start a transaction
final Txn transaction = getTransaction();
try {
final NotificationService notifier = context.getBroker().getBrokerPool().getNotificationService();
final StoredNode[] ql = selectAndLock(transaction, inSeq);
final IndexListener listener = new IndexListener(ql);
NodeImpl parent;
for (int i = 0; i < ql.length; i++) {
final StoredNode node = ql[i];
final DocumentImpl doc = (DocumentImpl)node.getOwnerDocument();
if (!doc.getPermissions().validate(context.getUser(), Permission.WRITE)) {
//transact.abort(transaction);
throw new PermissionDeniedException("User '" + context.getSubject().getName() + "' does not have permission to write to the document '" + doc.getDocumentURI() + "'!");
}
doc.getMetadata().setIndexListener(listener);
//update the document
parent = (NodeImpl) node.getParentNode();
if (parent==null) {
LOG.debug("Cannot remove the document element (no parent node)");
throw new XPathException(this,
"It is not possible to remove the document element.");
} else if (parent.getNodeType() != Node.ELEMENT_NODE) {
LOG.debug("parent = " + parent.getNodeType() + "; " + parent.getNodeName());
//transact.abort(transaction);
throw new XPathException(this,
"you cannot remove the document element. Use update "
+ "instead");
} else {
parent.removeChild(transaction, node);
}
doc.getMetadata().clearIndexListener();
doc.getMetadata().setLastModified(System.currentTimeMillis());
modifiedDocuments.add(doc);
context.getBroker().storeXMLResource(transaction, doc);
notifier.notifyUpdate(doc, UpdateListener.UPDATE);
}
finishTriggers(transaction);
//commit the transaction
commitTransaction(transaction);
} catch (final EXistException e) {
abortTransaction(transaction);
throw new XPathException(this, e.getMessage(), e);
} catch (final PermissionDeniedException e) {
abortTransaction(transaction);
throw new XPathException(this, e.getMessage(), e);
} catch (final LockException e) {
abortTransaction(transaction);
throw new XPathException(this, e.getMessage(), e);
} catch (final TriggerException e) {
abortTransaction(transaction);
throw new XPathException(this, e.getMessage(), e);
} finally {
unlockDocuments();
closeTransaction(transaction);
}
}
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", Sequence.EMPTY_SEQUENCE);}
return Sequence.EMPTY_SEQUENCE;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#dump(org.exist.xquery.util.ExpressionDumper)
*/
public void dump(ExpressionDumper dumper) {
// TODO Auto-generated method stub
}
public String toString() {
return "'Delete' string representation";
}
}