/*
* #!
* Ontopia Engine
* #-
* Copyright (C) 2001 - 2013 The Ontopia Project
* #-
* Licensed 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* !#
*/
package net.ontopia.topicmaps.query.impl.rdbms;
import java.util.List;
import net.ontopia.persistence.query.jdo.JDOBoolean;
import net.ontopia.persistence.query.jdo.JDOEquals;
import net.ontopia.persistence.query.jdo.JDOField;
import net.ontopia.persistence.query.jdo.JDONotEquals;
import net.ontopia.persistence.query.jdo.JDONull;
import net.ontopia.persistence.query.jdo.JDOObject;
import net.ontopia.persistence.query.jdo.JDOValueIF;
import net.ontopia.topicmaps.core.TopicIF;
import net.ontopia.topicmaps.core.TopicMapIF;
import net.ontopia.topicmaps.core.TypedIF;
import net.ontopia.topicmaps.query.core.InvalidQueryException;
/**
* INTERNAL: Implements the 'type(typed, type)' predicate.
*/
public class TypePredicate
extends net.ontopia.topicmaps.query.impl.basic.TypePredicate
implements JDOPredicateIF {
public TypePredicate(TopicMapIF topicmap) {
super(topicmap);
}
// --- JDOPredicateIF implementation
public boolean isRecursive() {
return false;
}
public void prescan(QueryBuilder builder, List arguments) {
}
public boolean buildQuery(QueryBuilder builder, List expressions, List arguments)
throws InvalidQueryException {
// Interpret arguments
Object[] args = arguments.toArray();
// TOLOG: type(TYPED, TYPE)
if (args[0] instanceof TypedIF && args[1] instanceof TopicIF) {
// Do direct predicate evaluation
if (args[1].equals(((TypedIF)args[0]).getType()))
expressions.add(JDOBoolean.TRUE);
else
expressions.add(JDOBoolean.FALSE);
} else {
JDOValueIF jv_typed = builder.createJDOValue(args[0]);
JDOValueIF jv_type = builder.createJDOValue(args[1]);
// JDOQL: O.type = T
expressions.add(new JDOEquals(new JDOField(jv_typed, "type"), jv_type));
// if variable: filter out nulls
if (jv_type.getType() == JDOValueIF.VARIABLE)
expressions.add(new JDONotEquals(jv_type, new JDONull()));
// JDOQL: O.topicmap = TOPICMAP
expressions.add(new JDOEquals(new JDOField(jv_typed, "topicmap"),
new JDOObject(topicmap)));
}
return true;
}
}