/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2009 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 java.util.List;
import org.exist.dom.QName;
import org.exist.xquery.AnalyzeContextInfo;
import org.exist.xquery.Atomize;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Dependency;
import org.exist.xquery.DynamicCardinalityCheck;
import org.exist.xquery.ErrorCodes;
import org.exist.xquery.Expression;
import org.exist.xquery.Function;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Profiler;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.util.Error;
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.StringValue;
import org.exist.xquery.value.Type;
/**
* Implements the library function fn:concat().
*
*/
public class FunConcat extends Function {
protected static final Logger logger = Logger.getLogger(FunConcat.class);
public final static FunctionSignature signature =
new FunctionSignature(
new QName("concat", Function.BUILTIN_FUNCTION_NS),
"Accepts two or more xdt:anyAtomicType arguments, $atomizable-values, " +
"and converts them to xs:string. Returns the xs:string that is the " +
"concatenation of the values of its arguments after conversion. " +
"If any of the arguments is the empty sequence, the argument " +
"is treated as the zero-length string.",
new SequenceType[] {
//More complicated : see below
new FunctionParameterSequenceType("atomizable-values",
Type.ATOMIC, Cardinality.ZERO_OR_ONE, "The atomizable values")
},
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE,
"The concatenated values"),
true
);
public FunConcat(XQueryContext context) {
super(context, signature);
}
public int returnsType() {
return Type.STRING;
}
/**
* Overloaded function: no static type checking.
*
* @see org.exist.xquery.Function#setArguments(java.util.List)
*/
public void setArguments(List<Expression> arguments) throws XPathException {
steps.clear();
for (Expression argument : arguments) {
if (!(argument instanceof Placeholder)) {
argument = new DynamicCardinalityCheck(context,
Cardinality.ZERO_OR_ONE, argument,
new Error(Error.FUNC_PARAM_CARDINALITY, "1", mySignature));
if (!Type.subTypeOf(argument.returnsType(), Type.ATOMIC))
{argument = new Atomize(context, argument);}
}
steps.add(argument);
}
}
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
contextInfo.setParent(this);
// call analyze for each argument
inPredicate = (contextInfo.getFlags() & IN_PREDICATE) > 0;
for(int i = 0; i < getArgumentCount(); i++) {
getArgument(i).analyze(contextInfo);
}
}
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 (getArgumentCount() < 2) {
throw new XPathException (this, ErrorCodes.XPST0017,
"concat() requires at least two arguments");
}
final StringBuilder concat = new StringBuilder();
for (int i = 0; i < getArgumentCount(); i++) {
concat.append(getArgument(i).eval(contextSequence, contextItem).getStringValue());
}
final Sequence result = new StringValue(concat.toString());
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
}