/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2016 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
*/
package org.exist.xquery.update;
import org.exist.EXistException;
import org.exist.collections.triggers.TriggerException;
import org.exist.dom.persistent.DocumentImpl;
import org.exist.dom.persistent.NodeImpl;
import org.exist.dom.persistent.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
*
*/
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()) {
//TODO: should we trap this instead of throwing an exception - deliriumsky?
throw xpe;
}
}
//END trap Delete failure
if (!inSeq.isEmpty()) {
//start a transaction
try (final Txn transaction = getTransaction()) {
final NotificationService notifier = context.getBroker().getBrokerPool().getNotificationService();
final StoredNode[] ql = selectAndLock(transaction, inSeq);
NodeImpl parent;
for (final StoredNode node : ql) {
final DocumentImpl doc = node.getOwnerDocument();
if (!doc.getPermissions().validate(context.getSubject(), Permission.WRITE)) {
//transact.abort(transaction);
throw new PermissionDeniedException("User '" + context.getSubject().getName() + "' does not have permission to write to the document '" + doc.getDocumentURI() + "'!");
}
//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) {
if (LOG.isDebugEnabled()) {
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().setLastModified(System.currentTimeMillis());
modifiedDocuments.add(doc);
context.getBroker().storeXMLResource(transaction, doc);
notifier.notifyUpdate(doc, UpdateListener.UPDATE);
}
finishTriggers(transaction);
//commit the transaction
transaction.commit();
} catch (final EXistException | PermissionDeniedException | LockException | TriggerException e) {
throw new XPathException(this, e.getMessage(), e);
} finally {
unlockDocuments();
}
}
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) {
dumper.display("delete").nl();
dumper.startIndent();
select.dump(dumper);
dumper.nl().endIndent();
}
public String toString() {
return "'Delete' string representation";
}
}