/*******************************************************************************
* Copyright (c) 2011, 2015 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.tools.model.query;
import java.io.IOException;
import java.util.List;
import org.eclipse.persistence.jpa.jpql.ExpressionTools;
import org.eclipse.persistence.jpa.jpql.parser.IdentificationVariable;
import org.eclipse.persistence.jpa.jpql.tools.model.Problem;
import org.eclipse.persistence.jpa.jpql.tools.spi.IManagedType;
import org.eclipse.persistence.jpa.jpql.tools.spi.IMapping;
import org.eclipse.persistence.jpa.jpql.tools.spi.IType;
import org.eclipse.persistence.jpa.jpql.tools.spi.ITypeDeclaration;
/**
* This state object represents a single identification variable, which is identifying TODO.
*
* @see IdentificationVariable
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
@SuppressWarnings("nls")
public class IdentificationVariableStateObject extends SimpleStateObject {
/**
* The {@link IManagedType} mapped to the identification variable if the identification variable
* maps to an entity name.
*/
private IManagedType managedType;
/**
*
*/
private IMapping mapping;
/**
* The {@link IType} of the object being mapped to this identification variable.
*/
private IType type;
/**
* The {@link ITypeDeclaration} of the object being mapped to this identification variable.
*/
private ITypeDeclaration typeDeclaration;
/**
* Determines whether this identification variable is virtual, meaning it's not part of the query
* but is required for proper navigability.
*/
private boolean virtual;
/**
* Notify a change in the defined property.
*/
public static final String DEFINED_PROPERTY = "defined";
/**
* Creates a new <code>IdentificationVariableStateObject</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 IdentificationVariableStateObject(StateObject parent) {
super(parent);
}
/**
* Creates a new <code>IdentificationVariableStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @param variable The name of the identification variable
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public IdentificationVariableStateObject(StateObject parent, String variable) {
super(parent, variable);
}
/**
* {@inheritDoc}
*/
public void accept(StateObjectVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
@Override
protected void addProblems(List<Problem> problems) {
super.addProblems(problems);
// String text = getText();
// An empty identification variable is never allowed
// if (ExpressionTools.stringIsEmpty(text)) {
// problems.add(buildProblem(StateObjectProblemConstants.IDENTIFICATION_VARIABLE_STATE_OBJECT_NO_TEXT));
// }
// // A JPQL identifier is never allowed
// else if (false) { //.isIdentifier(text)) {
// problems.add(buildProblem(StateObjectProblemConstants.IDENTIFICATION_VARIABLE_STATE_OBJECT_NOT_DEFINED));
// }
// // The identification variable contains some invalid characters
// // TODO
//
// // The variable is not defined in the FROM clause
// else if (!defined) {
// problems.add(buildProblem(StateObjectProblemConstants.IDENTIFICATION_VARIABLE_STATE_OBJECT_NOT_DEFINED));
// }
}
/**
* Makes sure the current identification variable and the given one are the same. If they are
* not, then clears the cached values related to the type.
*
* @param text The new identification variable
*/
protected void checkIntegrity(String text) {
if (ExpressionTools.valuesAreDifferent(getText(), text)) {
clearResolvedObjects();
}
}
/**
* Clears the values related to the managed type and type.
*/
protected void clearResolvedObjects() {
type = null;
managedType = null;
typeDeclaration = null;
}
/**
* {@inheritDoc}
*/
@Override
public IdentificationVariable getExpression() {
return (IdentificationVariable) super.getExpression();
}
/**
* Returns the {@link IManagedType} associated with the field handled by this object. If this
* object does not handle a field that has a {@link IManagedType}, then <code>null</code> should
* be returned.
* <p>
* For example: "<code><b>SELECT</b> e <b>FROM</b> Employee e</code>", the object for <i>e</i>
* would be returning the {@link IManagedType} for <i>Employee</i>.
*
* @return Either the {@link IManagedType}, if it could be resolved; <code>null</code> otherwise
*/
public IManagedType getManagedType() {
if ((managedType == null) && (mapping == null)) {
managedType = resolveManagedType();
}
return managedType;
}
/**
* Returns
*
* @return
*/
public IMapping getMapping() {
if ((managedType == null) && (mapping == null)) {
mapping = resolveMapping();
}
return mapping;
}
/**
* Returns the {@link IType} of the field handled by this object.
*
* @return Either the {@link IType} that was resolved by this state object or the {@link IType}
* for {@link IType#UNRESOLVABLE_TYPE} if it could not be resolved
*/
public IType getType() {
if (type == null) {
type = resolveType();
}
return type;
}
/**
* Returns the {@link ITypeDeclaration} of the field handled by this object.
*
* @return Either the {@link ITypeDeclaration} that was resolved by this object or the {@link
* ITypeDeclaration} for {@link IType#UNRESOLVABLE_TYPE} if it could not be resolved
*/
public ITypeDeclaration getTypeDeclaration() {
if (typeDeclaration == null) {
typeDeclaration = resolveTypeDeclaration();
}
return typeDeclaration;
}
/**
* {@inheritDoc}
*/
@Override
public boolean isEquivalent(StateObject stateObject) {
if (super.isEquivalent(stateObject)) {
IdentificationVariableStateObject variable = (IdentificationVariableStateObject) stateObject;
return ExpressionTools.stringsAreEqualIgnoreCase(getText(), variable.getText());
}
return false;
}
/**
* Determines whether this identification variable is virtual, meaning it's not part of the query
* but is required for proper navigability.
*
* @return <code>true</code> if this identification variable was virtually created to fully
* qualify path expression; <code>false</code> if it was parsed
*/
public boolean isVirtual() {
return virtual;
}
/**
* Retrieves the {@link IManagedType} that is mapped to the identification variable, if and only
* if the identification variable is used to declare an entity.
*
* @return Either the {@link IManagedType} declared by the identification variable or <code>null</code>
* if it could not be resolved
*/
protected IManagedType resolveManagedType() {
return getManagedTypeProvider().getManagedType(getType());
}
/**
* Resolves
*
* @return
*/
protected IMapping resolveMapping() {
return null;
}
/**
* Resolves the {@link IType} of the property handled by this object.
*
* @return Either the {@link IType} that was resolved by this object or the {@link IType} for
* {@link IType#UNRESOLVABLE_TYPE} if it could not be resolved
*/
protected IType resolveType() {
return getTypeDeclaration().getType();
}
/**
* Resolves the {@link ITypeDeclaration} of the property handled by this object.
*
* @return Either the {@link ITypeDeclaration} that was resolved by this object or the {@link
* ITypeDeclaration} for {@link IType#UNRESOLVABLE_TYPE} if it could not be resolved
*/
protected ITypeDeclaration resolveTypeDeclaration() {
return null;
}
/**
* Keeps a reference of the {@link IdentificationVariable 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 IdentificationVariable parsed object} representing an
* identification variable
*/
public void setExpression(IdentificationVariable expression) {
super.setExpression(expression);
}
/**
* {@inheritDoc}
*/
@Override
public void setText(String text) {
checkIntegrity(text);
super.setText(text);
}
/**
* Sets whether this identification variable is virtual, meaning it's not part of the query but
* is required for proper navigability.
*
* @param virtual <code>true</code> if this identification variable was virtually created to
* fully qualify path expression; <code>false</code> if it was parsed
*/
public void setVirtual(boolean virtual) {
this.virtual = virtual;
}
/**
* {@inheritDoc}
*/
@Override
protected void toTextInternal(Appendable writer) throws IOException {
if (!virtual) {
super.toTextInternal(writer);
}
}
}