/*******************************************************************************
* Copyright (c) 2011, 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.tools.model.query;
import java.io.IOException;
import org.eclipse.persistence.jpa.jpql.parser.InternalOrderByItemBNF;
import org.eclipse.persistence.jpa.jpql.parser.OrderByClause;
import org.eclipse.persistence.jpa.jpql.parser.OrderByItem.Ordering;
import org.eclipse.persistence.jpa.jpql.parser.OrderByItemBNF;
import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*;
import static org.eclipse.persistence.jpa.jpql.parser.Expression.*;
/**
* The <code><b>ORDER BY</b></code> clause allows the objects or values that are returned by the
* query to be ordered.
*
* <div><b>BNF:</b> <code>orderby_clause ::= <b>ORDER BY</b> {@link OrderByItemStateObject orderby_item} {, {@link OrderByItemStateObject orderby_item}}*</code><p></div>
*
* @see org.eclipse.persistence.jpa.jpql.parser.OrderByClause OrderByClause
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
@SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740
public class OrderByClauseStateObject extends AbstractListHolderStateObject<OrderByItemStateObject> {
/**
* Notify the list of {@link StateObject StateObjects} representing the <code><b>ORDER BY</b></code>
* items.
*/
public static final String ORDER_BY_ITEMS_LIST = "orderByItems";
/**
* Creates a new <code>OrderByClauseStateObject</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 OrderByClauseStateObject(SelectStatementStateObject parent) {
super(parent);
}
/**
* {@inheritDoc}
*/
public void accept(StateObjectVisitor visitor) {
visitor.visit(this);
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause.
*
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addItem() {
return addItem(Ordering.DEFAULT);
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause.
*
* @param ordering The ascending order
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addItem(Ordering ordering) {
OrderByItemStateObject updateItem = new OrderByItemStateObject(this, ordering);
addItem(updateItem);
return updateItem;
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause.
*
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addItem(String... paths) {
return addOrderByItem(paths, Ordering.DEFAULT);
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause.
*
* @param variable The identification variable or the result variable
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addItem(String variable) {
return addItem(variable, Ordering.DEFAULT);
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause.
*
* @param path The identification variable or the result variable
* @param ordering The ascending order
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addItem(String path, Ordering ordering) {
OrderByItemStateObject orderByItem = addItem(ordering);
orderByItem.setStateObject(buildStateObject(path, InternalOrderByItemBNF.ID));
return orderByItem;
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause with <code><b>ASC</b></code>.
*
* @param variable The identification variable or the result variable
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addItemAsc(String variable) {
return addItem(variable, Ordering.ASC);
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause with <code><b>DESC</b></code>.
*
* @param variable The identification variable or the result variable
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addItemDesc(String variable) {
return addItem(variable, Ordering.DESC);
}
/**
* Adds a new <code><b>ORDER BY</b></code> item to this clause.
*
* @param paths The paths or the item
* @param ordering The ascending order
* @return The newly added {@link OrderByItemStateObject}
*/
public OrderByItemStateObject addOrderByItem(String[] paths, Ordering ordering) {
StateFieldPathExpressionStateObject stateField = new StateFieldPathExpressionStateObject(this);
stateField.setPaths(paths);
OrderByItemStateObject updateItem = new OrderByItemStateObject(this, stateField, ordering);
addItem(updateItem);
return updateItem;
}
/**
* {@inheritDoc}
*/
@Override
public OrderByClause getExpression() {
return (OrderByClause) super.getExpression();
}
/**
* {@inheritDoc}
*/
@Override
public SelectStatementStateObject getParent() {
return (SelectStatementStateObject) super.getParent();
}
/**
* {@inheritDoc}
*/
@Override
public boolean isEquivalent(StateObject stateObject) {
return super.isEquivalent(stateObject) &&
areChildrenEquivalent((OrderByClauseStateObject) stateObject);
}
/**
* {@inheritDoc}
*/
@Override
protected String listName() {
return ORDER_BY_ITEMS_LIST;
}
/**
* Parses the given JPQL fragment, which represents either a single or many ordering items, the
* fragment will be parsed and converted into {@link OrderByItemStateObject}.
*
* @param jpqlFragment The portion of the query to parse
*/
public void parse(String jpqlFragment) {
// Note: No need to add the items here, they are automatically added by the builder
buildStateObjects(jpqlFragment, OrderByItemBNF.ID);
}
/**
* Keeps a reference of the {@link OrderByClause 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 OrderByClause parsed object} representing an <code><b>ORDER
* BY</b></code> clause
*/
public void setExpression(OrderByClause expression) {
super.setExpression(expression);
}
/**
* {@inheritDoc}
*/
@Override
protected void toTextInternal(Appendable writer) throws IOException {
writer.append(ORDER_BY);
if (hasItems()) {
writer.append(SPACE);
toStringItems(writer, true);
}
}
}