/*
* Copyright 2013 Robert von Burg <eitch@eitchnet.ch>
*
* 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 li.strolch.runtime.query.inmemory;
import java.util.List;
import li.strolch.model.Resource;
import li.strolch.model.ResourceVisitor;
import li.strolch.model.query.ResourceQuery;
import li.strolch.model.query.ResourceQueryVisitor;
import li.strolch.model.query.StrolchTypeNavigation;
import li.strolch.persistence.api.ResourceDao;
import li.strolch.utils.dbc.DBC;
/**
* @author Robert von Burg <eitch@eitchnet.ch>
*/
public class InMemoryResourceQueryVisitor extends InMemoryQueryVisitor<Resource, ResourceDao> implements
ResourceQueryVisitor {
public InMemoryResourceQueryVisitor() {
super();
}
@Override
protected InMemoryQueryVisitor<Resource, ResourceDao> newInstance() {
return new InMemoryResourceQueryVisitor();
}
public <U> InMemoryQuery<Resource, U> visit(ResourceQuery<U> resourceQuery) {
ResourceVisitor<U> resourceVisitor = resourceQuery.getResourceVisitor();
DBC.PRE.assertNotNull("ResourceVisitor may not be null!", resourceVisitor); //$NON-NLS-1$
resourceQuery.accept(this);
Navigator<Resource> navigator = getNavigator();
if (navigator == null) {
String msg = "Query is missing a navigation!"; //$NON-NLS-1$
throw new QueryException(msg);
}
List<Selector<Resource>> selectors = getSelectors();
if (selectors.isEmpty())
return new InMemoryQuery<>(navigator, null, resourceVisitor, getComparator());
DBC.INTERIM.assertTrue("Invalid query as it may only contain one selector!", selectors.size() == 1); //$NON-NLS-1$
return new InMemoryQuery<>(navigator, selectors.get(0), resourceVisitor, getComparator());
}
@Override
public void visit(StrolchTypeNavigation navigation) {
setNavigator(new ResourceTypeNavigator(navigation.getType()));
}
}