MWOneToManyMapping.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.mapping.relational;

import java.util.Iterator;
import java.util.Set;

import org.eclipse.persistence.tools.workbench.mappingsmodel.MWModel;
import org.eclipse.persistence.tools.workbench.mappingsmodel.db.MWColumn;
import org.eclipse.persistence.tools.workbench.mappingsmodel.db.MWColumnPair;
import org.eclipse.persistence.tools.workbench.mappingsmodel.descriptor.relational.MWRelationalClassDescriptor;
import org.eclipse.persistence.tools.workbench.mappingsmodel.mapping.MWMapping;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWClassAttribute;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWClassCodeGenPolicy;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWMethod;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWMethodCodeGenPolicy;

import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.mappings.DatabaseMapping;
import org.eclipse.persistence.mappings.OneToManyMapping;
import org.eclipse.persistence.oxm.XMLDescriptor;

public final class MWOneToManyMapping
    extends MWCollectionMapping
{

    private MWOneToManyMapping() {
        super();
    }

    MWOneToManyMapping(MWRelationalClassDescriptor descriptor, MWClassAttribute attribute, String name) {
        super(descriptor, attribute, name);
    }

    public MWOneToManyMapping asMWOneToManyMapping() {
        return this;
    }

    /**
    * IMPORTANT:  See MWRMapping class comment.
    */
    protected void initializeOn(MWMapping newMapping)  {
        newMapping.initializeFromMWOneToManyMapping(this);
    }

    /**
     * Return a 1-1 mapping in the reference descriptor that uses the same MWReference as this mapping
     */
    protected MWOneToOneMapping backPointerMapping() {
        if (getReferenceDescriptor() == null)
            return null;

        for (Iterator it = getReferenceDescriptor().mappings(); it.hasNext(); ) {
            MWMapping mapping = (MWMapping) it.next();

            if (mapping instanceof MWOneToOneMapping) {
                MWOneToOneMapping oneToOneMapping = (MWOneToOneMapping) mapping;

                if (oneToOneMapping.getReference() != null && oneToOneMapping.getReference() == this.getReference())
                    return oneToOneMapping;
            }
        }

        return null;
    }


    public boolean isOneToManyMapping(){
        return true;
    }

    /**
     * Used for code gen.
     * See MWMapping.accessorCodeGenPolicy(MWMethod)
     */
    public MWMethodCodeGenPolicy accessorCodeGenPolicy(MWMethod accessor, MWClassCodeGenPolicy classCodeGenPolicy)
    {
        // If TopLink maintains the relationship, we don't care about what attribute
        //  is the back pointer for this mapping's attribute.
        if (! this.maintainsBidirectionalRelationship())
        {
            MWMapping backPointerMapping = backPointerMapping();

            if (backPointerMapping != null)
                return getInstanceVariable().accessorCodeGenPolicy(accessor, backPointerMapping.getInstanceVariable(), this.isPrivateOwned(), classCodeGenPolicy);
        }

        return super.accessorCodeGenPolicy(accessor, classCodeGenPolicy);
    }

    // ************* MWQueryable implementation **************

    public String iconKey() {
        return "mapping.oneToMany";
    }


    // **************** Automap support ***************

    /**
     * one-to-many mappings are always "target foreign key"
     */
    protected Set buildCandidateReferences() {
        return this.buildCandidateTargetReferences();
    }


    // ************* runtime conversion **************

    protected DatabaseMapping buildRuntimeMapping() {
        return new OneToManyMapping();
    }

    public DatabaseMapping runtimeMapping() {
        OneToManyMapping runtimeMapping = (OneToManyMapping) super.runtimeMapping();
        if (getReference() != null) {
            for (Iterator stream = getReference().columnPairs(); stream.hasNext(); ) {
                MWColumnPair pair = (MWColumnPair) stream.next();
                MWColumn sourceColumn = pair.getSourceColumn();
                MWColumn targetColumn = pair.getTargetColumn();
                if ((sourceColumn != null) && (targetColumn != null)) {
                    if (!parentDescriptorIsAggregate()) {
                        runtimeMapping.addTargetForeignKeyFieldName(sourceColumn.qualifiedName(), targetColumn.qualifiedName());
                    }
                    else {
                        runtimeMapping.addTargetForeignKeyFieldName(sourceColumn.qualifiedName(), getName() + "->" + targetColumn.getName() + "_IN_REFERENCE_" + getReference().getName());
                    }
                }
            }
        }
        return runtimeMapping;
    }


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

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

        descriptor.setJavaClass(MWOneToManyMapping.class);
        descriptor.getInheritancePolicy().setParentClass(MWCollectionMapping.class);

        return descriptor;
    }

}