/*******************************************************************************
* Copyright (c) 2012, 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 <b>REGEXP</b> condition is used to specify a search for a pattern. It is not part of JPA
* 2.0/2.1, only EclipseLink. It is supported by many databases (Oracle, MySQL, PostgreSQL), I
* think part of SQL 2008, replacing <b>SIMILAR TO</b>.
* <p>
* The <code>string_expression</code> must have a string value. The <code>pattern_value</code> is a
* string literal or a string-valued input parameter that is a regular expression.
*
* <div><b>BNF:</b> <code>regexp_expression ::= string_expression REGEXP pattern_value</code></div>
*
* @version 2.5
* @since 2.4
* @author James Sutherland
*/
public final class RegexpExpression extends AbstractExpression {
/**
* Determines whether a whitespace was parsed after <b>REGEXP</b>.
*/
private boolean hasSpaceAfterIdentifier;
/**
* The {@link Expression} representing the pattern value.
*/
private AbstractExpression patternValue;
/**
* The actual <b>REGEXP</b> identifier found in the string representation of the JPQL query.
*/
private String regexpIdentifier;
/**
* The {@link Expression} representing the string expression.
*/
private AbstractExpression stringExpression;
/**
* Creates a new <code>LikeExpression</code>.
*
* @param parent The parent of this expression
* @param stringExpression The first part of this expression, which is the string expression
*/
public RegexpExpression(AbstractExpression parent, AbstractExpression stringExpression) {
super(parent, REGEXP);
if (stringExpression != null) {
this.stringExpression = stringExpression;
this.stringExpression.setParent(this);
}
}
/**
* {@inheritDoc}
*/
public void accept(ExpressionVisitor visitor) {
acceptUnknownVisitor(visitor);
}
/**
* {@inheritDoc}
*/
public void acceptChildren(ExpressionVisitor visitor) {
getStringExpression().accept(visitor);
getPatternValue().accept(visitor);
}
/**
* {@inheritDoc}
*/
@Override
protected void addChildrenTo(Collection<Expression> children) {
children.add(getStringExpression());
children.add(getPatternValue());
}
/**
* {@inheritDoc}
*/
@Override
protected void addOrderedChildrenTo(List<Expression> children) {
// String expression
if (stringExpression != null) {
children.add(stringExpression);
children.add(buildStringExpression(SPACE));
}
// 'REGEXP'
children.add(buildStringExpression(REGEXP));
if (hasSpaceAfterIdentifier) {
children.add(buildStringExpression(SPACE));
}
// Pattern value
if (patternValue != null) {
children.add(patternValue);
}
}
/**
* {@inheritDoc}
*/
@Override
public JPQLQueryBNF findQueryBNF(Expression expression) {
if ((stringExpression != null) && stringExpression.isAncestor(expression)) {
return getQueryBNF(StringExpressionBNF.ID);
}
if ((patternValue != null) && patternValue.isAncestor(expression)) {
return getQueryBNF(PatternValueBNF.ID);
}
return super.findQueryBNF(expression);
}
/**
* Returns the actual <b>REGEXP</b> found in the string representation of the JPQL query, which
* has the actual case that was used.
*
* @return The <b>REGEXP</b> identifier that was actually parsed
*/
public String getActualRegexpIdentifier() {
return regexpIdentifier;
}
/**
* Returns the {@link Expression} that represents the pattern value.
*
* @return The expression that was parsed representing the pattern value
*/
public Expression getPatternValue() {
if (patternValue == null) {
patternValue = buildNullExpression();
}
return patternValue;
}
/**
* {@inheritDoc}
*/
public JPQLQueryBNF getQueryBNF() {
return getQueryBNF(RegexpExpressionBNF.ID);
}
/**
* Returns the {@link Expression} that represents the string expression.
*
* @return The expression that was parsed representing the string expression
*/
public Expression getStringExpression() {
if (stringExpression == null) {
stringExpression = buildNullExpression();
}
return stringExpression;
}
/**
* Determines whether the pattern value was parsed.
*
* @return <code>true</code> if the pattern value was parsed; <code>false</code> otherwise
*/
public boolean hasPatternValue() {
return patternValue != null &&
!patternValue.isNull();
}
/**
* Determines whether a whitespace was parsed after <b>REGEXP</b>.
*
* @return <code>true</code> if there was a whitespace after <b>REGEXP</b>; <code>false</code>
* otherwise
*/
public boolean hasSpaceAfterIdentifier() {
return hasSpaceAfterIdentifier;
}
/**
* Determines whether a whitespace was parsed after the string expression.
*
* @return <code>true</code> if there was a whitespace after the string expression;
* <code>false</code> otherwise
*/
public boolean hasSpaceAfterStringExpression() {
return hasStringExpression();
}
/**
* Determines whether the string expression was parsed.
*
* @return <code>true</code> if the string expression was parsed; <code>false</code> otherwise
*/
public boolean hasStringExpression() {
return stringExpression != null &&
!stringExpression.isNull();
}
/**
* {@inheritDoc}
*/
@Override
protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) {
char character = word.charAt(0);
if (getQueryBNF(PatternValueBNF.ID).handleAggregate() &&
(character == '+' || character == '-' || character == '*' || character == '/')) {
return false;
}
return super.isParsingComplete(wordParser, word, expression) ||
word.equalsIgnoreCase(AND) ||
word.equalsIgnoreCase(OR) ||
expression != null;
}
/**
* {@inheritDoc}
*/
@Override
protected void parse(WordParser wordParser, boolean tolerant) {
// Parse 'REGEXP'
regexpIdentifier = wordParser.moveForward(REGEXP);
hasSpaceAfterIdentifier = wordParser.skipLeadingWhitespace() > 0;
// Parse the pattern value
patternValue = parse(wordParser, PatternValueBNF.ID, tolerant);
}
/**
* {@inheritDoc}
*/
@Override
protected void toParsedText(StringBuilder writer, boolean actual) {
// String expression
if (stringExpression != null) {
stringExpression.toParsedText(writer, actual);
writer.append(SPACE);
}
// 'REGEXP'
writer.append(actual ? regexpIdentifier : REGEXP);
if (hasSpaceAfterIdentifier) {
writer.append(SPACE);
}
// Pattern value
if (patternValue != null) {
patternValue.toParsedText(writer, actual);
}
}
}