/*
* eXist Open Source Native XML Database
* Copyright (C) 2005-2009 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 program; if not, write to the Free Software Foundation
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.functions.fn;
import org.apache.log4j.Logger;
import org.exist.dom.QName;
import org.exist.xquery.*;
import org.exist.xquery.functions.xmldb.XMLDBModule;
import org.exist.xquery.util.DocUtils;
import org.exist.xquery.value.BooleanValue;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
/**
* Implements the XQuery's fn:doc-available() function.
*
* @author Pierrick Brihaye <pierrick.brihaye@free.fr>
* @author wolf
*/
public class FunDocAvailable extends Function {
protected static final Logger logger = Logger.getLogger(FunDocAvailable.class);
public final static FunctionSignature signature =
new FunctionSignature(
new QName("doc-available", Function.BUILTIN_FUNCTION_NS),
"Returns whether or not the document, $document-uri, " +
"specified in the input sequence is available. " +
XMLDBModule.ANY_URI,
new SequenceType[] {
new FunctionParameterSequenceType("document-uri", Type.STRING,
Cardinality.ZERO_OR_ONE, "The document URI")
},
new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.EXACTLY_ONE,
"true() if the document is available, false() otherwise"));
public FunDocAvailable(XQueryContext context) {
super(context, signature);
}
/**
* @see org.exist.xquery.Function#getDependencies()
*/
public int getDependencies() {
return Dependency.CONTEXT_SET;
}
/**
* @see org.exist.xquery.Expression#eval(Sequence, 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());}
}
Sequence result;
final Sequence arg = getArgument(0).eval(contextSequence, contextItem);
if (arg.isEmpty()) {
result = BooleanValue.FALSE;
} else {
final String path = arg.itemAt(0).getStringValue();
try {
result = BooleanValue.valueOf(DocUtils.isDocumentAvailable(this.context, path));
} catch (final XPathException e) {
e.prependMessage(ErrorCodes.FODC0005, "");
throw e;
}
}
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
/**
* @see org.exist.xquery.Expression#resetState(boolean)
* @param postOptimization
*/
public void resetState(boolean postOptimization) {
super.resetState(postOptimization);
getArgument(0).resetState(postOptimization);
}
}