| /* |
| * Copyright (c) 2006, 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.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * An identification variable is a valid identifier declared in the <b>FROM</b> clause of a query. |
| * All identification variables must be declared in the <b>FROM</b> clause. Identification variables |
| * cannot be declared in other clauses. An identification variable must not be a reserved identifier |
| * or have the same name as any entity in the same persistence unit: Identification variables are |
| * case insensitive. An identification variable evaluates to a value of the type of the expression |
| * used in declaring the variable. |
| * |
| * <div><b>BNF:</b> <code>identification_variable_declaration ::= range_variable_declaration { join | fetch_join }*</code></div> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class IdentificationVariableDeclaration extends AbstractExpression { |
| |
| /** |
| * Determines whether there is a space after the range variable declaration. |
| */ |
| private boolean hasSpace; |
| |
| /** |
| * The unique join (fetch join) or list of join (fetch join) expression or a <code>null</code> |
| * expression if none was declared. |
| */ |
| private AbstractExpression joins; |
| |
| /** |
| * Flag used to determine how to check if the parsing is complete. |
| */ |
| private boolean parsingJoinExpression; |
| |
| /** |
| * The variable declaration, which is the abstract schema name and the variable. |
| */ |
| private AbstractExpression rangeVariableDeclaration; |
| |
| /** |
| * Creates a new <code>IdentificationVariableDeclaration</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public IdentificationVariableDeclaration(AbstractExpression parent) { |
| super(parent); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getRangeVariableDeclaration().accept(visitor); |
| getJoins().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getRangeVariableDeclaration()); |
| children.add(getJoins()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| if (rangeVariableDeclaration != null) { |
| children.add(rangeVariableDeclaration); |
| } |
| |
| if (hasSpace) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| if (joins != null) { |
| children.add(joins); |
| } |
| } |
| |
| /** |
| * Creates a new {@link CollectionExpression} that will wrap the single join expression. |
| * |
| * @return The single join expression represented by a temporary collection |
| */ |
| public CollectionExpression buildCollectionExpression() { |
| |
| List<AbstractExpression> children = new ArrayList<>(1); |
| children.add((AbstractExpression) getJoins()); |
| |
| List<Boolean> commas = new ArrayList<>(1); |
| commas.add(Boolean.FALSE); |
| |
| List<Boolean> spaces = new ArrayList<>(1); |
| spaces.add(Boolean.FALSE); |
| |
| return new CollectionExpression(this, children, commas, spaces, true); |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((rangeVariableDeclaration != null) && rangeVariableDeclaration.isAncestor(expression)) { |
| return getQueryBNF(RangeVariableDeclarationBNF.ID); |
| } |
| |
| if ((joins != null) && joins.isAncestor(expression)) { |
| return getQueryBNF(InternalJoinBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the unique join (fetch join) or the list of joins (fetch joins) expression. |
| * |
| * @return The <code>JOIN</code> expression(s) or a <code>null</code> expression if none was declared |
| */ |
| public Expression getJoins() { |
| if (joins == null) { |
| joins = buildNullExpression(); |
| } |
| return joins; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(IdentificationVariableDeclarationBNF.ID); |
| } |
| |
| /** |
| * Returns the variable declaration, which is the abstract schema name and the identification |
| * variable. |
| * |
| * @return The {@link Expression} representing the range variable declaration |
| */ |
| public Expression getRangeVariableDeclaration() { |
| if (rangeVariableDeclaration == null) { |
| rangeVariableDeclaration = buildNullExpression(); |
| } |
| return rangeVariableDeclaration; |
| } |
| |
| /** |
| * Determines whether this declaration has any join expressions. |
| * |
| * @return <code>true</code> if at least one join expression was specified; <code>false</code> |
| * otherwise |
| */ |
| public boolean hasJoins() { |
| return joins != null && |
| !joins.isNull(); |
| } |
| |
| /** |
| * Determines whether the range variable declaration was parsed. |
| * |
| * @return <code>true</code> if the range variable declaration was parsed; <code>false</code> |
| * otherwise |
| */ |
| public boolean hasRangeVariableDeclaration() { |
| return rangeVariableDeclaration != null && |
| !rangeVariableDeclaration.isNull(); |
| } |
| |
| /** |
| * Determines whether there is a space after the range variable declaration. |
| * |
| * @return <code>true</code> if the range variable declaration is followed by a space, |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpace() { |
| return hasSpace; |
| } |
| |
| @Override |
| protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) { |
| |
| // Parsing the join expressions |
| if (parsingJoinExpression) { |
| return !word.equalsIgnoreCase(JOIN) && |
| !word.equalsIgnoreCase(INNER) && |
| !word.equalsIgnoreCase(OUTER) && |
| !word.equalsIgnoreCase(LEFT); |
| } |
| |
| // Parsing the range variable declaration |
| return word.equalsIgnoreCase(JOIN) || |
| word.equalsIgnoreCase(INNER) || |
| word.equalsIgnoreCase(LEFT) || |
| word.equalsIgnoreCase(OUTER) || |
| word.equalsIgnoreCase(IN) || |
| super.isParsingComplete(wordParser, word, expression); |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse the range variable declaration |
| if (tolerant) { |
| rangeVariableDeclaration = parse(wordParser, RangeVariableDeclarationBNF.ID, tolerant); |
| } |
| else { |
| rangeVariableDeclaration = new RangeVariableDeclaration(this); |
| rangeVariableDeclaration.parse(wordParser, tolerant); |
| } |
| |
| int count = wordParser.skipLeadingWhitespace(); |
| |
| // Parse the JOIN expressions |
| parsingJoinExpression = true; |
| joins = parse(wordParser, InternalJoinBNF.ID, tolerant); |
| |
| // If there are no JOIN expressions and there is more text to parse, then re-add the space so |
| // it can be owned by a parent expression. The only exception to that is if it's followed by |
| // a comma, the space will be kept as a virtual space (it will not be part of the string |
| // representation) |
| if (!hasJoins() && (wordParser.character() != COMMA)) { |
| wordParser.moveBackward(count); |
| } |
| else { |
| hasSpace = (count > 0); |
| } |
| } |
| |
| @Override |
| protected boolean shouldParseWithFactoryFirst() { |
| return parsingJoinExpression; |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| // Range Variable Declaration |
| if (rangeVariableDeclaration != null) { |
| rangeVariableDeclaration.toParsedText(writer, actual); |
| } |
| |
| if (hasSpace) { |
| writer.append(SPACE); |
| } |
| |
| // Joins |
| if (joins != null) { |
| joins.toParsedText(writer, actual); |
| } |
| } |
| } |