# RemoveAssociation.java

    /*
     * Copyright (c) 2009, Rickard Öberg. All Rights Reserved.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     *
     */

    package org.qi4j.migration.operation;

    import org.json.JSONException;
    import org.json.JSONObject;
    import org.qi4j.migration.Migrator;
    import org.qi4j.migration.assembly.EntityMigrationOperation;
    import org.qi4j.spi.entitystore.helpers.StateStore;

    /**
     * Remove an association. Downgrading this operation will reset
     * the property to the default value.
     */
    public class RemoveAssociation
        implements EntityMigrationOperation
    {
        private String association;
        private String defaultValue;

        public RemoveAssociation( String association, String defaultReference )
        {
            this.association = association;
            this.defaultValue = defaultReference;
        }

        @Override
        public boolean upgrade( JSONObject state, StateStore stateStore, Migrator migrator )
            throws JSONException
        {
            return migrator.removeAssociation( state, association );
        }

        @Override
        public boolean downgrade( JSONObject state, StateStore stateStore, Migrator migrator )
            throws JSONException
        {
            return migrator.addAssociation( state, association, defaultValue );
        }

        @Override
        public String toString()
        {
            return "Remove association " + association + ", default:" + defaultValue;
        }
    }