MWQueryParameterArgument.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.mappingsmodel.ProblemConstants;
import org.eclipse.persistence.tools.workbench.mappingsmodel.handles.MWDescriptorQueryParameterHandle;
import org.eclipse.persistence.tools.workbench.mappingsmodel.handles.MWHandle;
import org.eclipse.persistence.tools.workbench.mappingsmodel.handles.MWHandle.NodeReferenceScrubber;
import org.eclipse.persistence.tools.workbench.mappingsmodel.query.MWQueryParameter;
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.expressions.ExpressionBuilder;
import org.eclipse.persistence.internal.expressions.ParameterExpression;
import org.eclipse.persistence.oxm.XMLDescriptor;
import org.eclipse.persistence.oxm.mappings.XMLCompositeObjectMapping;

/**
 * An MWQueryParameterArgument is only used as the right hand side of a MWBinaryExpression
 * The user chooses a parameter from the MWQuery's list of parameters.  It is then held on to
 * by the DescriptorQueryParameterHandle
 *
 * If the chosen parameter is deleted from the query, this object is notified and the parameter
 * is set to null.  The queryParameterArgument held on to by the BasicExpression is not set to null.
 */
public final class MWQueryParameterArgument extends MWArgument {

    private MWDescriptorQueryParameterHandle queryParameterHandle;
        // property change
        public final static String QUERY_PARAMETER_PROPERTY = "queryParameter";

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

    MWQueryParameterArgument(MWBasicExpression expression)
    {
        super(expression);
    }

    MWQueryParameterArgument(MWBasicExpression expression, MWQueryParameter parameter)
    {
        this(expression);
        this.queryParameterHandle.setQueryParameter(parameter);
    }

    protected void initialize(Node parent) {
        super.initialize(parent);
        this.queryParameterHandle = new MWDescriptorQueryParameterHandle(this, this.buildQueryParameterScrubber());
    }

    public String getType() {
        return PARAMETER_TYPE;
    }

    public MWQueryParameter getQueryParameter() {
        return this.queryParameterHandle.getQueryParameter();
    }

    private MWBasicExpression getBasicExpression() {
        return (MWBasicExpression) getParent();
    }


    //*********** problem support ****************

    protected void addProblemsTo(List currentProblems) {
        super.addProblemsTo(currentProblems);
        this.checkParameter(currentProblems);
    }

    private void checkParameter(List currentProblems) {
        if (this.getQueryParameter() == null) {
            String queryName = this.getBasicExpression().getParentQuery().getName();
            String lineNumber = this.getBasicExpression().getIndex();
            currentProblems.add(this.buildProblem(ProblemConstants.DESCRIPTOR_QUERY_EXPRESSION_NO_PARAMETER_SPECIFIED,
                     lineNumber, queryName));
        }
    }


    // ********** model synchronization support **********

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

    private NodeReferenceScrubber buildQueryParameterScrubber() {
        return new NodeReferenceScrubber() {
            public void nodeReferenceRemoved(Node node, MWHandle handle) {
                MWQueryParameterArgument.this.setQueryParameter(null);
            }
            public String toString() {
                return "MWQueryParameterArgument.buildQueryParameterScrubber()";
            }
        };
    }


    /**
     * @see org.eclipse.persistence.tools.workbench.mappingsmodel.query.Restorable#undoChange(String, Object)
     */
    public void undoChange(String propertyName, Object oldValue, Object newValue)
    {
        if (propertyName == QUERY_PARAMETER_PROPERTY)
            setQueryParameter((MWQueryParameter) oldValue);
    }

    public String displayString()
    {
        if (getQueryParameter() == null)
            return "";
        return getQueryParameter().getName();
    }

    public void toString(StringBuffer sb)
    {
        super.toString(sb);
        sb.append("queryParameter = ");
        if (getQueryParameter() != null) {
            sb.append(getQueryParameter().getName());
        }
    }

    public void setQueryParameter(MWQueryParameter queryParameter)
    {
        MWQueryParameter oldQueryParameter = getQueryParameter();
        this.queryParameterHandle.setQueryParameter(queryParameter);
        firePropertyChanged(QUERY_PARAMETER_PROPERTY, oldQueryParameter, getQueryParameter());
        getBasicExpression().getRootCompoundExpression().propertyChanged(this, QUERY_PARAMETER_PROPERTY, oldQueryParameter, queryParameter);
    }


    // ********** Conversion to Runtime **********

    Expression runtimeExpression(ExpressionBuilder builder) {
        return builder.getParameter(getQueryParameter().getName());
    }

    static MWQueryParameterArgument convertFromRuntime(MWBasicExpression bldrExpression, ParameterExpression runtimeExpression)     {
        String parameterName = runtimeExpression.getField().getName();
        MWQueryParameter parameter  = bldrExpression.getParentQuery().getParameterNamed(parameterName);
        return new MWQueryParameterArgument(bldrExpression, parameter);
    }


    // ********** TopLink methods **********

    public static XMLDescriptor buildDescriptor() {
        XMLDescriptor descriptor = new XMLDescriptor();
        descriptor.setJavaClass(MWQueryParameterArgument.class);
        descriptor.getInheritancePolicy().setParentClass(MWArgument.class);

        XMLCompositeObjectMapping queryParameterHandleMapping = new XMLCompositeObjectMapping();
        queryParameterHandleMapping.setAttributeName("queryParameterHandle");
        queryParameterHandleMapping.setGetMethodName("getQueryParameterHandleForTopLink");
        queryParameterHandleMapping.setSetMethodName("setQueryParameterHandleForTopLink");
        queryParameterHandleMapping.setReferenceClass(MWDescriptorQueryParameterHandle.class);
        queryParameterHandleMapping.setXPath("query-parameter-handle");
        descriptor.addMapping(queryParameterHandleMapping);
        return descriptor;
    }

    /**
     * check for null
     */
    private MWDescriptorQueryParameterHandle getQueryParameterHandleForTopLink() {
        return (this.queryParameterHandle.getQueryParameter() == null) ? null : this.queryParameterHandle;
    }
    private void setQueryParameterHandleForTopLink(MWDescriptorQueryParameterHandle handle) {
        NodeReferenceScrubber scrubber = this.buildQueryParameterScrubber();
        this.queryParameterHandle = ((handle == null) ? new MWDescriptorQueryParameterHandle(this, scrubber) : handle.setScrubber(scrubber));
    }

}