MWExpressionQueryFormat.java

/*******************************************************************************
 * Copyright (c) 1998, 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 from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.mappingsmodel.query.relational;

import java.util.List;

import org.eclipse.persistence.tools.workbench.mappingsmodel.MWModel;
import org.eclipse.persistence.tools.workbench.utility.node.Node;

import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.oxm.XMLDescriptor;
import org.eclipse.persistence.oxm.mappings.XMLCompositeObjectMapping;
import org.eclipse.persistence.queries.DatabaseQuery;
import org.eclipse.persistence.queries.ObjectLevelReadQuery;

/**
 * This class holds on to the expression for queries which have expression format chosen
 */
public final class MWExpressionQueryFormat extends MWQueryFormat
{
    //expression can never be null
    private volatile MWCompoundExpression expression;
        public final static String EXPRESSION_PROPERTY = "expression";

    /**
     * Default constructor - for TopLink use only.
     */
    private MWExpressionQueryFormat()
    {
        super();
    }

    MWExpressionQueryFormat(MWRelationalSpecificQueryOptions parent)
    {
        super(parent);
    }

    protected void addChildrenTo(List children)
    {
        super.addChildrenTo(children);
        children.add(expression);
    }

    /**
     * initialize persistent state
     */
    protected void initialize(Node modelObject)
    {
        super.initialize(modelObject);
        expression = new MWCompoundExpression(this);
    }

    String getType() {
        return MWRelationalQuery.EXPRESSION_FORMAT;
    }

    public MWCompoundExpression getExpression()
    {
        return expression;
    }

    public void setExpression(MWCompoundExpression expression)
    {
        MWCompoundExpression oldExpression = getExpression();
        this.expression = expression;
        firePropertyChanged(EXPRESSION_PROPERTY, oldExpression, getExpression());
    }

    public boolean orderingAttributesAllowed() {
        return true;
    }

    public boolean batchReadAttributesAllowed() {
        return true;
    }

    public boolean reportAttributesAllowed() {
        return true;
    }

    public boolean groupingAtributesAllowed() {
        return true;
    }
    public void toString(StringBuffer sb)
    {
        super.toString(sb);
        sb.append(", expression = ");
        sb.append(getExpression());
    }

    //persistence
    public static XMLDescriptor buildDescriptor()
    {
        XMLDescriptor descriptor = new XMLDescriptor();

        descriptor.setJavaClass(MWExpressionQueryFormat.class);
        descriptor.getInheritancePolicy().setParentClass(MWQueryFormat.class);

        // 1-1 to the compound expression
        XMLCompositeObjectMapping expressionMapping = new XMLCompositeObjectMapping();
        expressionMapping.setAttributeName("expression");
        expressionMapping.setReferenceClass(MWCompoundExpression.class);
        expressionMapping.setXPath("main-compound-expression");
        descriptor.addMapping(expressionMapping);

        return descriptor;
    }

    //Conversion methods
    void convertToRuntime(DatabaseQuery runtimeQuery)
    {
        runtimeQuery.setSelectionCriteria(getExpression().buildRuntimeExpression(((ObjectLevelReadQuery)runtimeQuery).getExpressionBuilder()));
    }
    void convertFromRuntime(DatabaseQuery runtimeQuery)
    {
        Expression selectionCriteria = runtimeQuery.getSelectionCriteria();

        if (selectionCriteria != null)
        {
            setExpression(MWCompoundExpression.convertFromRuntime(this, selectionCriteria));
        }
    }
}