    001    // Copyright 2010, 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.internal.transform;
    016
    017    import org.apache.tapestry5.ComponentResources;
    018    import org.apache.tapestry5.plastic.FieldConduit;
    019    import org.apache.tapestry5.plastic.InstanceContext;
    020
    021    /**
    022     * An implementation of {@link FieldConduit} for a read-only component field. Subclasses
    023     * provide an implementation of the {@link #get(Object, org.apache.tapestry5.plastic.InstanceContext)} method.
    024     *
    025     * @since 5.2.0
    026     */
    027    public abstract class ReadOnlyComponentFieldConduit implements FieldConduit<Object>
    028    {
    029        private final String qualifiedFieldName;
    030
    031        public ReadOnlyComponentFieldConduit(String qualifiedFieldName)
    032        {
    033            this.qualifiedFieldName = qualifiedFieldName;
    034        }
    035
    036        public ReadOnlyComponentFieldConduit(String className, String fieldName)
    037        {
    038            this(String.format("%s.%s", className, fieldName));
    039        }
    040
    041        public ReadOnlyComponentFieldConduit(ComponentResources resources, String fieldName)
    042        {
    043            this(resources.getComponentModel().getComponentClassName(), fieldName);
    044        }
    045
    046        public void set(Object instance, InstanceContext context, Object newValue)
    047        {
    048            throw new RuntimeException(String.format("Field %s is read only.", qualifiedFieldName));
    049        }
    050    }