<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
 this work for additional information regarding copyright ownership.
 The ASF licenses this file to You under the Apache License, Version 2.0
 (the "License"); you may not use this file except in compliance with
 the License.  You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
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 See the License for the specific language governing permissions and
 limitations under the License.
-->
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/Document">
<!-- This template uses an efficient, cached filter for the "genre" field".
	Other query fields are fed directly through an analyzer and so do not need to adhere to  
	traditional Lucene query syntax. Terms within a field are ORed while different fields are ANDed
 -->	
<FilteredQuery>
	<Query>
		<BooleanQuery>
			<xsl:if test="count(artist)>0">
			    <Clause occurs="must">
			      <TermsQuery fieldName="artist"><xsl:value-of select="artist"/></TermsQuery>
			   </Clause>
		   </xsl:if>
			<xsl:if test="count(album)>0">
			    <Clause occurs="must">
			      <TermsQuery fieldName="album"><xsl:value-of select="album"/></TermsQuery>
			   </Clause>
		   </xsl:if>
			<xsl:if test="count(releaseDate)>0">
			    <Clause occurs="must">
			      <TermsQuery fieldName="releaseDate"><xsl:value-of select="releaseDate"/></TermsQuery>
			   </Clause>
		   </xsl:if>
	</BooleanQuery>
	</Query>
	<Filter>
		<CachedFilter>
			<!-- Example filter to be cached for fast, repeated use -->
			<TermsFilter fieldName="genre">			
				<xsl:value-of select="genre"/>
			</TermsFilter>
		</CachedFilter>		
	</Filter>	
</FilteredQuery>
</xsl:template>
</xsl:stylesheet>