| /* |
| * Copyright (c) 2012, 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.parser; |
| |
| import java.util.Collection; |
| import java.util.List; |
| import org.eclipse.persistence.jpa.jpql.ExpressionTools; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * Defines a table expression. This allow a non-mapped table to be used in a query. This is not part |
| * of the JPA functional specification but is EclipseLink specific support. |
| * |
| * <div><b>BNF:</b> <code>table_variable_declaration ::= table_expression [AS] identification_variable</code></div> |
| * |
| * @version 2.5 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| public final class TableVariableDeclaration extends AbstractExpression { |
| |
| /** |
| * The actual <b>AS</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String asIdentifier; |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>AS</b>. |
| */ |
| private boolean hasSpaceAfterAs; |
| |
| /** |
| * Determines whether a whitespace was parsed after the "root" object. |
| */ |
| private boolean hasSpaceAfterTableExpression; |
| |
| /** |
| * The {@link Expression} representing the identification variable. |
| */ |
| private AbstractExpression identificationVariable; |
| |
| /** |
| * The {@link Expression} representing the database table. |
| */ |
| private TableExpression tableExpression; |
| |
| /** |
| * Creates a new <code>TableVariableDeclaration</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public TableVariableDeclaration(AbstractExpression parent) { |
| super(parent); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| acceptUnknownVisitor(visitor); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getTableExpression().accept(visitor); |
| getIdentificationVariable().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getTableExpression()); |
| children.add(getIdentificationVariable()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| // Table expression |
| children.add(tableExpression); |
| |
| // Space |
| if (hasSpaceAfterTableExpression) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // 'AS' |
| if (asIdentifier != null) { |
| children.add(buildStringExpression(AS)); |
| } |
| |
| if (hasSpaceAfterAs) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // Identification variable |
| if (identificationVariable != null) { |
| children.add(identificationVariable); |
| } |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((tableExpression != null) && tableExpression.isAncestor(expression)) { |
| return getQueryBNF(TableExpressionBNF.ID); |
| } |
| |
| if ((identificationVariable != null) && identificationVariable.isAncestor(expression)) { |
| return getQueryBNF(IdentificationVariableBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the actual <b>AS</b> found in the string representation of the JPQL query, which has |
| * the actual case that was used. |
| * |
| * @return The <b>AS</b> identifier that was actually parsed, or an empty string if it was not parsed |
| */ |
| public String getActualAsIdentifier() { |
| return (asIdentifier != null) ? asIdentifier : ExpressionTools.EMPTY_STRING; |
| } |
| |
| /** |
| * Returns the {@link Expression} that represents the identification variable. |
| * |
| * @return The expression that was parsed representing the identification variable |
| */ |
| public Expression getIdentificationVariable() { |
| if (identificationVariable == null) { |
| identificationVariable = buildNullExpression(); |
| } |
| return identificationVariable; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(TableVariableDeclarationBNF.ID); |
| } |
| |
| /** |
| * Returns the {@link TableExpression} that specify the database table. |
| * |
| * @return The expression that was parsed specifying the database table |
| */ |
| public TableExpression getTableExpression() { |
| return tableExpression; |
| } |
| |
| /** |
| * Determines whether the identifier <b>AS</b> was parsed. |
| * |
| * @return <code>true</code> if the identifier <b>AS</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasAs() { |
| return asIdentifier != null; |
| } |
| |
| /** |
| * Determines whether the identification variable was parsed. |
| * |
| * @return <code>true</code> if the identification variable was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasIdentificationVariable() { |
| return identificationVariable != null && |
| !identificationVariable.isNull() && |
| !identificationVariable.isVirtual(); |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>AS</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after <b>AS</b>; <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterAs() { |
| return hasSpaceAfterAs; |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after the table expression. |
| * |
| * @return <code>true</code> if there was a whitespace after the table expression; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterTableExpression() { |
| return hasSpaceAfterTableExpression; |
| } |
| |
| @Override |
| protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) { |
| return word.equalsIgnoreCase(AS) || |
| super.isParsingComplete(wordParser, word, expression); |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse the table expression |
| tableExpression = new TableExpression(this); |
| tableExpression.parse(wordParser, tolerant); |
| |
| hasSpaceAfterTableExpression = wordParser.skipLeadingWhitespace() > 0; |
| |
| // Parse 'AS' |
| if (wordParser.startsWithIdentifier(AS)) { |
| asIdentifier = wordParser.moveForward(AS); |
| hasSpaceAfterAs = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse the identification variable |
| if (tolerant) { |
| identificationVariable = parse(wordParser, IdentificationVariableBNF.ID, tolerant); |
| } |
| else { |
| identificationVariable = new IdentificationVariable(this, wordParser.word()); |
| identificationVariable.parse(wordParser, tolerant); |
| } |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| // Table expression |
| tableExpression.toParsedText(writer, actual); |
| |
| if (hasSpaceAfterTableExpression) { |
| writer.append(SPACE); |
| } |
| |
| // 'AS' |
| if (asIdentifier != null) { |
| writer.append(actual ? asIdentifier : AS); |
| } |
| |
| if (hasSpaceAfterAs) { |
| writer.append(SPACE); |
| } |
| |
| // Identification variable |
| if (identificationVariable != null) { |
| identificationVariable.toParsedText(writer, actual); |
| } |
| } |
| } |