/*
* 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, 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 org.apache.openjpa.persistence.criteria;
import javax.persistence.criteria.Root;
import javax.persistence.metamodel.EntityType;
import org.apache.openjpa.kernel.exps.AbstractExpressionBuilder;
import org.apache.openjpa.kernel.exps.Context;
import org.apache.openjpa.kernel.exps.ExpressionFactory;
import org.apache.openjpa.kernel.exps.Path;
import org.apache.openjpa.kernel.exps.Subquery;
import org.apache.openjpa.kernel.exps.Value;
import org.apache.openjpa.persistence.meta.MetamodelImpl;
import org.apache.openjpa.persistence.meta.Types;
/**
* A root path without a parent.
*
* @param <X> the type of the entity
*
* @author Pinaki Poddar
* @author Fay Wang
*
* @since 2.0.0
*/
class RootImpl<X> extends FromImpl<X,X> implements Root<X> {
private final Types.Entity<X> _entity;
public RootImpl(Types.Entity<X> type) {
super(type);
_entity = type;
}
public EntityType<X> getModel() {
return _entity;
}
public void addToContext(ExpressionFactory factory, MetamodelImpl model, CriteriaQueryImpl<?> q) {
String alias = q.getAlias(this);
Value var = factory.newBoundVariable(alias, AbstractExpressionBuilder.TYPE_OBJECT);
var.setMetaData(_entity.meta);
Context currContext = q.ctx();
currContext.addSchema(alias, _entity.meta);
currContext.addVariable(alias, var);
if (currContext.schemaAlias == null)
currContext.schemaAlias = alias;
}
/**
* Convert this path to a kernel path value.
*/
@Override
public Value toValue(ExpressionFactory factory, CriteriaQueryImpl<?> c) {
SubqueryImpl<?> subquery = c.getDelegator();
Path var = null;
Value val = null;
String alias = c.getAlias(this);
if (c.ctx() != null && !alias.equalsIgnoreCase(c.ctx().schemaAlias)
&& (val = c.getRegisteredRootVariable(this)) != null) {
// this is cross join
var = factory.newPath(val);
} else if (inSubquery(subquery)) {
Subquery subQ = subquery.getSubQ();
var = factory.newPath(subQ);
} else {
var = factory.newPath();
var.setSchemaAlias(alias);
}
var.setMetaData(_entity.meta);
return var;
}
/**
* Convert this path to a kernel expression.
*
*/
@Override
public org.apache.openjpa.kernel.exps.Expression toKernelExpression(
ExpressionFactory factory, CriteriaQueryImpl<?> c) {
Value path = toValue(factory, c);
Value var = factory.newBoundVariable(c.getAlias(this),
_entity.meta.getDescribedType());
return factory.bindVariable(var, path);
}
public StringBuilder asValue(AliasContext q) {
Value v = q.getRegisteredRootVariable(this);
if (v != null)
return new StringBuilder(v.getAlias());
v = q.getRegisteredValue(this);
if (v != null)
return new StringBuilder(v.getAlias());
if (q.isRegistered(this))
return new StringBuilder(q.getRegisteredValue(this).getName());
return new StringBuilder().append(Character.toLowerCase(_entity.getName().charAt(0)));
}
public StringBuilder asVariable(AliasContext q) {
return new StringBuilder(_entity.getName()).append(" ").append(asValue(q));
}
}