FunContains.java

/*
 * 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;

import java.text.Collator;

import org.exist.dom.QName;
import org.exist.util.Collations;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Constants;
import org.exist.xquery.Dependency;
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.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;

public class FunContains extends CollatingFunction {

	public final static FunctionSignature signatures[] = {
		new FunctionSignature(
			new QName("contains", Function.BUILTIN_FUNCTION_NS),
			"Returns an xs:boolean indicating whether or not the value of $source-string " +
			"contains (at the beginning, at the end, or anywhere within) at least " +
			"one sequence of collation units that provides a minimal match to the " +
			"collation units in the value of $substring, according to the default collation.",
			new SequenceType[] {
                new FunctionParameterSequenceType("source-string", Type.STRING, Cardinality.ZERO_OR_ONE, "The source-string"),
                new FunctionParameterSequenceType("substring", Type.STRING, Cardinality.ZERO_OR_ONE, "The substring")
			},
			new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.ONE, "true() if $source-string contains $substring, false() otherwise")),
		new FunctionSignature(
			new QName("contains", Function.BUILTIN_FUNCTION_NS),
			"Returns an xs:boolean indicating whether or not the value of $source-string " +
			"contains (at the beginning, at the end, or anywhere within) at least " +
			"one sequence of collation units that provides a minimal match to the " +
			"collation units in the value of $substring, according to the collation that is " +
			"specified in $collation-uri." + THIRD_REL_COLLATION_ARG_EXAMPLE,
			new SequenceType[] {
                new FunctionParameterSequenceType("source-string", Type.STRING, Cardinality.ZERO_OR_ONE, "The source-string"),
                new FunctionParameterSequenceType("substring", Type.STRING, Cardinality.ZERO_OR_ONE, "The substring"),
                new FunctionParameterSequenceType("collation-uri", Type.STRING, Cardinality.EXACTLY_ONE, "The collation URI")
					
			},
			new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.ONE, "true() if $source-string contains $substring, false() otherwise"))
	};

	public FunContains(XQueryContext context, FunctionSignature signature) {
		super(context, signature);
	}

	public int returnsType() {
		return Type.BOOLEAN;
	}

	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;
		//s2 takes precedence over s1
		String s2 = getArgument(1).eval(contextSequence, contextItem).getStringValue();
		if ("".equals(s2))
			result = BooleanValue.TRUE;
		else {
			String s1 = getArgument(0).eval(contextSequence, contextItem).getStringValue();
			if ("".equals(s1))
				result = BooleanValue.FALSE;
			else {
				Collator collator = getCollator(contextSequence, contextItem, 3);
				if (Collations.indexOf(collator, s1, s2) != Constants.STRING_NOT_FOUND)
					return BooleanValue.TRUE;
				else
					return BooleanValue.FALSE;
			}
		}

		if (context.getProfiler().isEnabled()) 
            context.getProfiler().end(this, "", result);        
        
        return result;        
	}
}