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/*
* 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.ArrayList;
import java.util.List;
import org.eclipse.persistence.jpa.jpql.parser.AbstractFromClause;
import org.eclipse.persistence.jpa.jpql.tools.model.Problem;
import org.eclipse.persistence.jpa.jpql.tools.spi.IEntity;
import org.eclipse.persistence.jpa.jpql.tools.spi.IManagedType;
import org.eclipse.persistence.jpa.jpql.tools.utility.iterable.SnapshotCloneIterable;
import org.eclipse.persistence.jpa.jpql.utility.CollectionTools;
import org.eclipse.persistence.jpa.jpql.utility.iterable.ListIterable;
import static org.eclipse.persistence.jpa.jpql.ExpressionTools.*;
import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*;
/**
* This state object represents the abstract definition of a FROM clause, which
* is either the FROM clause of the query or of a sub-query expression.
*
* @see AbstractSelectStatementStateObject
* @see FromClauseStateObject
*
* @see AbstractFromClause
*
* @version 2.5
* @since 2.4
* @author Pascal Filion
*/
@SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740
public abstract class AbstractFromClauseStateObject extends AbstractListHolderStateObject
implements DeclarationStateObject {
/**
* Notifies the content of the list of {@link VariableDeclarationStateObject} has changed.
*/
public static final String VARIABLE_DECLARATIONS_LIST = "variableDeclarations";
/**
* Creates a new AbstractFromClauseStateObject.
*
* @param parent The parent of this state object, which cannot be null
* @exception NullPointerException The given parent cannot be null
*/
protected AbstractFromClauseStateObject(AbstractSelectStatementStateObject parent) {
super(parent);
}
/**
* Adds a new collection declaration to the FROM clause.
*
* @return The {@link CollectionMemberDeclarationStateObject} representing the collection declaration
*/
public CollectionMemberDeclarationStateObject addCollectionDeclaration() {
CollectionMemberDeclarationStateObject stateObject = new CollectionMemberDeclarationStateObject(this);
addItem(stateObject);
return stateObject;
}
/**
* Adds a new collection declaration to the FROM clause.
*
* @param collectionValuedPath The collection-valued path expression
* @param identificationVariable The variable defining the collection-valued path expression
* @return The {@link CollectionMemberDeclarationStateObject} representing the collection
* declaration
*/
public CollectionMemberDeclarationStateObject addCollectionDeclaration(String collectionValuedPath,
String identificationVariable) {
CollectionMemberDeclarationStateObject stateObject = new CollectionMemberDeclarationStateObject(this);
stateObject.setPath(collectionValuedPath);
stateObject.setIdentificationVariable(identificationVariable);
addItem(stateObject);
return stateObject;
}
@Override
protected void addProblems(List currentProblems) {
super.addProblems(currentProblems);
// TODO
}
/**
* Adds a new range variable declaration to the FROM clause.
*
* @return The {@link StateObject} representing the range variable declaration
*/
public IdentificationVariableDeclarationStateObject addRangeDeclaration() {
IdentificationVariableDeclarationStateObject stateObject = new IdentificationVariableDeclarationStateObject(this);
addItem(stateObject);
return stateObject;
}
/**
* Adds to this select statement a new range variable declaration.
*
* @param entity The external form of the entity to add to the declaration list
* @param identificationVariable The unique identifier identifying the abstract schema name
* @return The state object of the new declaration
*/
public IdentificationVariableDeclarationStateObject addRangeDeclaration(IEntity entity,
String identificationVariable) {
IdentificationVariableDeclarationStateObject stateObject = new IdentificationVariableDeclarationStateObject(
this,
entity,
identificationVariable
);
addItem(stateObject);
return stateObject;
}
/**
* Adds a new range variable declaration.
*
* @param entityName The name of the entity name
* @param identificationVariable The new identification variable
* @return The state object of the new declaration
*/
public IdentificationVariableDeclarationStateObject addRangeDeclaration(String entityName,
String identificationVariable) {
IdentificationVariableDeclarationStateObject stateObject = new IdentificationVariableDeclarationStateObject(
this,
entityName,
identificationVariable
);
addItem(stateObject);
return stateObject;
}
/**
* Returns the BNF of the declaration part of this clause.
*
* @return The BNF of the declaration part of this clause
*/
protected abstract String declarationBNF();
@Override
public ListIterable declarations() {
return items();
}
@Override
public IdentificationVariableStateObject findIdentificationVariable(String variable) {
for (IdentificationVariableStateObject identificationVariable : identificationVariables()) {
if (stringsAreEqualIgnoreCase(identificationVariable.getText(), variable)) {
return identificationVariable;
}
}
return null;
}
@Override
public DeclarationStateObject getDeclaration() {
return this;
}
@Override
public AbstractFromClause getExpression() {
return (AbstractFromClause) super.getExpression();
}
@Override
public IManagedType getManagedType(StateObject stateObject) {
for (VariableDeclarationStateObject declaration : declarations()) {
IManagedType managedType = declaration.getManagedType(stateObject);
if (managedType != null) {
return managedType;
}
}
return null;
}
@Override
public AbstractSelectStatementStateObject getParent() {
return (AbstractSelectStatementStateObject) super.getParent();
}
/**
* Returns the {@link IdentificationVariableStateObject IdentificationVariableStateObjects}
* holding onto the identification variables, which are the variables defined in the
* FROM clause.
*
* Example:
*
* Employee e; e is returnedIN (e.employees) AS emps; emps is returnedManager m JOIN m.employees emps; m and emps are returned
*
* @return The list of {@link IdentificationVariableStateObject IdentificationVariableStateObjects}
*/
public Iterable identificationVariables() {
List stateObjects = new ArrayList<>();
for (VariableDeclarationStateObject stateObject : items()) {
CollectionTools.addAll(stateObjects, stateObject.identificationVariables());
}
return new SnapshotCloneIterable<>(stateObjects);
}
@Override
public boolean isEquivalent(StateObject stateObject) {
return super.isEquivalent(stateObject) &&
areChildrenEquivalent((AbstractListHolderStateObject) stateObject);
}
@Override
protected String listName() {
return VARIABLE_DECLARATIONS_LIST;
}
/**
* Parses the given JPQL fragment and create the select item. For the top-level query, the
* fragment can contain several select items but for a subquery, it can represent only one.
*
* @param jpqlFragment The portion of the query representing one or several select items
*/
public void parse(String jpqlFragment) {
// No need to add the items, they are automatically added by the builder
buildStateObjects(jpqlFragment, declarationBNF());
}
@Override
protected void toTextInternal(Appendable writer) throws IOException {
writer.append(FROM);
writer.append(SPACE);
toStringItems(writer, true);
}
}