/*******************************************************************************
* Copyright (c) 2006, 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.parser;
import java.util.Collection;
import java.util.List;
import org.eclipse.persistence.jpa.jpql.WordParser;
/**
* The <code>new_value</code> specified for an update operation must be compatible in type with the
* field to which it is assigned.
*
* <div><b>BNF:</b> <code>update_item ::= [identification_variable.]{state_field | single_valued_association_field} = new_value</code><p></div>
*
* @see UpdateClause
*
* @version 2.5
* @since 2.3
* @author Pascal Filion
*/
public final class UpdateItem extends AbstractExpression {
/**
* Determines whether the equal sign was parsed or not.
*/
private boolean hasEqualSign;
/**
* Determines whether a whitespace was parsed after the equal sign or not.
*/
private boolean hasSpaceAfterEqualSign;
/**
* Determines whether a whitespace was parsed before the equal sign or not
*/
private boolean hasSpaceAfterStateFieldPathExpression;
/**
* The expression representing the new value.
*/
private AbstractExpression newValue;
/**
* The expression representing the state field to have its value updated.
*/
private AbstractExpression stateFieldExpression;
/**
* Creates a new <code>UpdateItem</code>.
*
* @param parent The parent of this expression
*/
public UpdateItem(AbstractExpression parent) {
super(parent);
}
/**
* {@inheritDoc}
*/
public void accept(ExpressionVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
public void acceptChildren(ExpressionVisitor visitor) {
getStateFieldPathExpression().accept(visitor);
getNewValue().accept(visitor);
}
/**
* {@inheritDoc}
*/
@Override
protected void addChildrenTo(Collection<Expression> children) {
children.add(getStateFieldPathExpression());
children.add(getNewValue());
}
/**
* {@inheritDoc}
*/
@Override
protected void addOrderedChildrenTo(List<Expression> children) {
// State field expression
if (stateFieldExpression != null) {
children.add(stateFieldExpression);
}
if (hasSpaceAfterStateFieldPathExpression) {
children.add(buildStringExpression(SPACE));
}
// '='
if (hasEqualSign) {
children.add(buildStringExpression(EQUAL));
}
if (hasSpaceAfterEqualSign) {
children.add(buildStringExpression(SPACE));
}
// New value
if (newValue != null) {
children.add(newValue);
}
}
/**
* {@inheritDoc}
*/
@Override
public JPQLQueryBNF findQueryBNF(Expression expression) {
if ((stateFieldExpression != null) && stateFieldExpression.isAncestor(expression)) {
return getQueryBNF(UpdateItemStateFieldPathExpressionBNF.ID);
}
if ((newValue != null) && newValue.isAncestor(expression)) {
return getQueryBNF(NewValueBNF.ID);
}
return super.findQueryBNF(expression);
}
/**
* Returns the {@link Expression} representing the new value, which is the new value of the property.
*
* @return The expression for the new value
*/
public Expression getNewValue() {
if (newValue == null) {
newValue = buildNullExpression();
}
return newValue;
}
/**
* {@inheritDoc}
*/
public JPQLQueryBNF getQueryBNF() {
return getQueryBNF(UpdateItemBNF.ID);
}
/**
* Returns the {@link Expression} representing the state field path expression, which is the
* property that should get updated.
*
* @return The expression for the state field path expression
*/
public Expression getStateFieldPathExpression() {
if (stateFieldExpression == null) {
stateFieldExpression = buildNullExpression();
}
return stateFieldExpression;
}
/**
* Determines whether the equal sign was parsed or not.
*
* @return <code>true</code> if the equal sign was parsed; <code>false</code> otherwise
*/
public boolean hasEqualSign() {
return hasEqualSign;
}
/**
* Determines whether the new value section of the query was parsed.
*
* @return <code>true</code> the new value was parsed; <code>false</code> if nothing was parsed
*/
public boolean hasNewValue() {
return newValue != null &&
!newValue.isNull();
}
/**
* Determines whether a whitespace was parsed after the equal sign or not.
*
* @return <code>true</code> if there was a whitespace after the equal sign; <code>false</code> otherwise
*/
public boolean hasSpaceAfterEqualSign() {
return hasSpaceAfterEqualSign;
}
/**
* Determines whether a whitespace was parsed after the state field path expression not.
*
* @return <code>true</code> if there was a whitespace after the state field path expression;
* <code>false</code> otherwise
*/
public boolean hasSpaceAfterStateFieldPathExpression() {
return hasSpaceAfterStateFieldPathExpression;
}
/**
* Determines whether the state field was parsed.
*
* @return <code>true</code> the state field was parsed; <code>false</code> otherwise
*/
public boolean hasStateFieldPathExpression() {
return stateFieldExpression != null &&
!stateFieldExpression.isNull();
}
/**
* {@inheritDoc}
*/
@Override
protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) {
return word.equals(EQUAL) ||
super.isParsingComplete(wordParser, word, expression);
}
/**
* {@inheritDoc}
*/
@Override
protected void parse(WordParser wordParser, boolean tolerant) {
// Parse state field
if (tolerant) {
stateFieldExpression = parse(wordParser, UpdateItemStateFieldPathExpressionBNF.ID, tolerant);
}
else {
stateFieldExpression = new StateFieldPathExpression(this, wordParser.word());
stateFieldExpression.parse(wordParser, tolerant);
}
hasSpaceAfterStateFieldPathExpression = wordParser.skipLeadingWhitespace() > 0;
// Parse '='
hasEqualSign = wordParser.startsWith(EQUAL);
if (hasEqualSign) {
wordParser.moveForward(1);
hasSpaceAfterEqualSign = wordParser.skipLeadingWhitespace() > 0;
if (stateFieldExpression != null) {
hasSpaceAfterStateFieldPathExpression = true;
}
}
// Parse new value
newValue = parse(wordParser, NewValueBNF.ID, tolerant);
if (!hasSpaceAfterEqualSign && (newValue != null)) {
hasSpaceAfterEqualSign = true;
}
}
/**
* {@inheritDoc}
*/
@Override
protected void toParsedText(StringBuilder writer, boolean actual) {
// State field expression
if (stateFieldExpression != null) {
stateFieldExpression.toParsedText(writer, actual);
}
if (hasSpaceAfterStateFieldPathExpression) {
writer.append(SPACE);
}
// '='
if (hasEqualSign) {
writer.append(EQUAL);
}
if (hasSpaceAfterEqualSign) {
writer.append(SPACE);
}
// New value
if (newValue != null) {
newValue.toParsedText(writer, actual);
}
}
}