/*******************************************************************************
* Copyright (c) 2011, 2013 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation
*
******************************************************************************/
package org.eclipse.persistence.jpa.jpql.model.query;
import org.eclipse.persistence.jpa.jpql.TypeHelper;
import org.eclipse.persistence.jpa.jpql.parser.StateFieldPathExpression;
import org.eclipse.persistence.jpa.jpql.spi.IManagedType;
import org.eclipse.persistence.jpa.jpql.spi.IManagedTypeProvider;
import org.eclipse.persistence.jpa.jpql.spi.IManagedTypeVisitor;
import org.eclipse.persistence.jpa.jpql.spi.IMapping;
import org.eclipse.persistence.jpa.jpql.spi.IType;
import org.eclipse.persistence.jpa.jpql.spi.ITypeDeclaration;
import org.eclipse.persistence.jpa.jpql.util.iterator.IterableIterator;
import org.eclipse.persistence.jpa.jpql.util.iterator.NullIterator;
/**
* A single-valued association field is designated by the name of an association-field in a
* one-to-one or many-to-one relationship. The type of a single-valued association field and thus a
* single-valued association path expression is the abstract schema type of the related entity.
* <p>
* <div nowrap><b>BNF:</b> <code>state_field_path_expression ::= {identification_variable | single_valued_association_path_expression}.state_field</code><p>
* <p>
* <div nowrap><b>BNF:</b> <code>single_valued_association_path_expression ::= identification_variable.{single_valued_association_field.}*single_valued_association_field</code><p>
*
* @see StateFieldPathExpression
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
public class StateFieldPathExpressionStateObject extends AbstractPathExpressionStateObject {
/**
* Creates a new <code>StateFieldPathExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public StateFieldPathExpressionStateObject(StateObject parent) {
super(parent);
}
/**
* Creates a new <code>StateFieldPathExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @param path The state field path expression
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public StateFieldPathExpressionStateObject(StateObject parent, String path) {
super(parent, path);
}
/**
* {@inheritDoc}
*/
public void accept(StateObjectVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
@Override
public StateFieldPathExpression getExpression() {
return (StateFieldPathExpression) super.getExpression();
}
/**
* {@inheritDoc}
*/
@Override
protected IManagedType resolveManagedType() {
IMapping mapping = getMapping();
if (mapping == null) {
return null;
}
TypeHelper typeHelper = getTypeHelper();
ITypeDeclaration typeDeclaration = mapping.getTypeDeclaration();
IType type = typeDeclaration.getType();
// Collection type cannot be traversed
if (typeHelper.isCollectionType(type)) {
ITypeDeclaration[] typeParameters = typeDeclaration.getTypeParameters();
if (typeParameters.length == 0) {
return null;
}
type = typeParameters[0].getType();
}
// Wrap the Map into a virtual IManagedType so it can be returned and the
// IType for the Map can be used to retrieve the type of the key and value
else if (typeHelper.isMapType(type)) {
return new MapManagedType(getManagedTypeProvider(), type);
}
// Retrieve the corresponding managed type for the mapping's type
return getManagedTypeProvider().getManagedType(type);
}
/**
* {@inheritDoc}
*/
@Override
protected IType resolveType() {
return getTypeHelper().convertPrimitive(getTypeDeclaration().getType());
}
/**
* Keeps a reference of the {@link StateFieldPathExpression parsed object} object, which
* should only be done when this object is instantiated during the conversion of a parsed JPQL
* query into {@link StateObject StateObjects}.
*
* @param expression The {@link StateFieldPathExpression parsed object} representing a state
* field path expression
*/
public void setExpression(StateFieldPathExpression expression) {
super.setExpression(expression);
}
protected static class MapManagedType implements IManagedType {
protected final IType mapType;
protected final IManagedTypeProvider provider;
protected MapManagedType(IManagedTypeProvider provider, IType mapType) {
super();
this.mapType = mapType;
this.provider = provider;
}
/**
* {@inheritDoc}
*/
public void accept(IManagedTypeVisitor visitor) {
}
/**
* {@inheritDoc}
*/
public int compareTo(IManagedType managedType) {
return getType().getName().compareTo(managedType.getType().getName());
}
/**
* {@inheritDoc}
*/
public IMapping getMappingNamed(String name) {
return null;
}
/**
* {@inheritDoc}
*/
public IManagedTypeProvider getProvider() {
return provider;
}
/**
* {@inheritDoc}
*/
public IType getType() {
return mapType;
}
/**
* {@inheritDoc}
*/
public IterableIterator<IMapping> mappings() {
return NullIterator.instance();
}
/**
* {@inheritDoc}
*/
@Override
public String toString() {
return getType().getName();
}
}
}