| /* |
| * Copyright (c) 2011, 2021 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 v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0, |
| * or the Eclipse Distribution License v. 1.0 which is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause |
| */ |
| |
| // 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.parser.InternalWhenClauseBNF; |
| import org.eclipse.persistence.jpa.jpql.parser.ScalarExpressionBNF; |
| import org.eclipse.persistence.jpa.jpql.parser.WhenClause; |
| import org.eclipse.persistence.jpa.jpql.tools.model.Problem; |
| import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*; |
| |
| /** |
| * A <code><b>WHEN</b></code> predicate is used to calculate a condition and when it's true, its |
| * <code><b>THEN</b></code> will be executed. |
| * |
| * <div><p><b>BNF:</b> <code>when_clause ::= WHEN conditional_expression THEN scalar_expression</code></p></div> |
| * or |
| * <div><p><b>BNF:</b> <code>simple_when_clause ::= WHEN scalar_expression THEN scalar_expression</code></p></div> |
| * |
| * @see org.eclipse.persistence.jpa.jpql.parser.WhenClause WhenClause |
| * |
| * @version 2.4 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| @SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740 |
| public class WhenClauseStateObject extends AbstractConditionalClauseStateObject { |
| |
| /** |
| * The {@link StateObject} representing the scalar expression that is following the |
| * <code><b>THEN</b></code> identifier. |
| */ |
| private StateObject thenStateObject; |
| |
| /** |
| * Notify the {@link StateObject} representing the scalar expression that follows the |
| * <code><b>THEN</b></code> identifier has changed. |
| */ |
| public static final String THEN_STATE_OBJECT_PROPERTY = "thenStateObject"; |
| |
| /** |
| * Creates a new <code>WhenClauseStateObject</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 WhenClauseStateObject(CaseExpressionStateObject parent) { |
| super(parent); |
| } |
| |
| /** |
| * Creates a new <code>WhenClauseStateObject</code>. |
| * |
| * @param parent The parent of this state object |
| * @param whenStateObject The {@link StateObject} representing the conditional expression that |
| * is following the <code><b>WHEN</b></code> identifier |
| * @param thenStateObject The {@link StateObject} representing the scalar expression that |
| * is following the <code><b>THEN</b></code> identifier |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public WhenClauseStateObject(CaseExpressionStateObject parent, |
| StateObject whenStateObject, |
| StateObject thenStateObject) { |
| |
| super(parent, whenStateObject); |
| this.thenStateObject = parent(thenStateObject); |
| } |
| |
| /** |
| * Creates a new <code>WhenClauseStateObject</code>. |
| * |
| * @param parent The parent of this state object |
| * @param whenJpqlFragment The string representation of the <code><b>WHEN</b></code> clause to |
| * parse and to convert into a {@link StateObject} |
| * @param thenJpqlFragment The string representation of the <code><b>THEN</b></code> expression |
| * to parse and to convert into a {@link StateObject} |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public WhenClauseStateObject(CaseExpressionStateObject parent, |
| String whenJpqlFragment, |
| String thenJpqlFragment) { |
| |
| super(parent); |
| parseWhen(whenJpqlFragment); |
| parseThen(thenJpqlFragment); |
| } |
| |
| @Override |
| public void accept(StateObjectVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| protected void addChildren(List<StateObject> children) { |
| super.addChildren(children); |
| if (thenStateObject != null) { |
| children.add(thenStateObject); |
| } |
| } |
| |
| @Override |
| protected void addProblems(List<Problem> problems) { |
| |
| super.addProblems(problems); |
| |
| // if (!hasWhenStateObject()) { |
| // problems.add(buildProblem(StateObjectProblem.WhenClauseStateObject_MissingWhenStateObject)); |
| // } |
| |
| if (!hasThen()) { |
| problems.add(buildProblem(StateObjectProblem.WhenClauseStateObject_MissingThenStateObject)); |
| } |
| } |
| |
| @Override |
| public WhenClause getExpression() { |
| return (WhenClause) super.getExpression(); |
| } |
| |
| @Override |
| public String getIdentifier() { |
| return WHEN; |
| } |
| |
| @Override |
| public CaseExpressionStateObject getParent() { |
| return (CaseExpressionStateObject) super.getParent(); |
| } |
| |
| /** |
| * Returns the {@link StateObject} representing the scalar expression that is following the |
| * <code><b>THEN</b></code> identifier. |
| * |
| * @return Either the {@link StateObject} representing the <code><b>THEN</b></code> expression |
| * or <code>null</code> if it's not defined |
| */ |
| public StateObject getThen() { |
| return thenStateObject; |
| } |
| |
| /** |
| * Determines whether the {@link StateObject} representing the scalar expression is present. |
| * |
| * @return <code>true</code> the scalar expression exists; otherwise <code>false</code> |
| */ |
| public boolean hasThen() { |
| return thenStateObject != null; |
| } |
| |
| @Override |
| public boolean isEquivalent(StateObject stateObject) { |
| |
| if (super.isEquivalent(stateObject)) { |
| WhenClauseStateObject whenClause = (WhenClauseStateObject) stateObject; |
| return areEquivalent(thenStateObject, whenClause.thenStateObject); |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Parses the given JPQL fragment, which will represent the <code><b>THEN</b></code> expression. |
| * The JPQL fragment should not start with the identifier. |
| * |
| * @param jpqlFragment The string representation of the <code><b>THEN</b></code> expression |
| * to parse and to convert into a {@link StateObject} |
| */ |
| public void parseThen(String jpqlFragment) { |
| StateObject stateObject = buildStateObject(jpqlFragment, ScalarExpressionBNF.ID); |
| setThen(stateObject); |
| } |
| |
| /** |
| * Parses the given JPQL fragment, which will represent the <code><b>WHEN</b></code> clause. |
| * The JPQL fragment should not start with the identifier. |
| * |
| * @param jpqlFragment The string representation of the <code><b>WHEN</b></code> clause to |
| * parse and to convert into a {@link StateObject} |
| */ |
| public void parseWhen(String jpqlFragment) { |
| StateObject stateObject = buildStateObject(jpqlFragment, InternalWhenClauseBNF.ID); |
| setConditional(stateObject); |
| } |
| |
| /** |
| * Keeps a reference of the {@link WhenClause 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 WhenClause parsed object} representing a <code><b>WHEN</b></code> |
| * clause |
| */ |
| public void setExpression(WhenClause expression) { |
| super.setExpression(expression); |
| } |
| |
| /** |
| * Sets the scalar expression to be the given {@link StateObject}. |
| * |
| * @param thenStateObject The {@link StateObject} representing the scalar expression |
| */ |
| public void setThen(StateObject thenStateObject) { |
| StateObject oldThenStateObject = this.thenStateObject; |
| this.thenStateObject = parent(thenStateObject); |
| firePropertyChanged(THEN_STATE_OBJECT_PROPERTY, oldThenStateObject, thenStateObject); |
| } |
| |
| @Override |
| public void toTextInternal(Appendable writer) throws IOException { |
| |
| super.toTextInternal(writer); |
| writer.append(SPACE); |
| |
| // THEN scalar_expression |
| writer.append(THEN); |
| |
| if (thenStateObject != null) { |
| writer.append(SPACE); |
| thenStateObject.toString(writer); |
| } |
| } |
| } |