org.apache.wicket.model.ComponentPropertyModel.java Source code

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Here is the source code for org.apache.wicket.model.ComponentPropertyModel.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.wicket.model;

import org.apache.wicket.Component;
import org.apache.wicket.core.util.lang.PropertyResolver;

/**
 * A model that references a property by name on the current model of the component it is bound to.
 * This enables direct usage of inherited models such as compound property models.
 * 
 * @author Jonathan Locke
 * 
 * @param <T>
 *            The Model object
 */
public class ComponentPropertyModel<T> implements IComponentAssignedModel<T> {
    private static final long serialVersionUID = 1L;

    /** Name of property to read */
    private final String propertyName;

    /**
     * Constructor
     * 
     * @param propertyName
     *            The name of the property to reference
     */
    public ComponentPropertyModel(final String propertyName) {
        this.propertyName = propertyName;
    }

    @Override
    public T getObject() {
        throw new IllegalStateException("Wrapper should have been called");
    }

    @Override
    public final void setObject(T object) {
        IComponentAssignedModel.super.setObject(object);
    }

    @Override
    public IWrapModel<T> wrapOnAssignment(final Component component) {
        return new AssignmentWrapper<T>(component, propertyName);
    }

    /**
     * Wrapper used when assigning a ComponentPropertyModel to a component.
     * 
     * @param <P>
     *            The Model Object
     */
    private class AssignmentWrapper<P> implements IWrapModel<P> {
        private static final long serialVersionUID = 1L;

        private final Component component;

        private final String propertyName;

        AssignmentWrapper(final Component component, final String propertyName) {
            this.component = component;
            this.propertyName = propertyName;
        }

        @Override
        public IModel<T> getWrappedModel() {
            return ComponentPropertyModel.this;
        }

        protected String propertyExpression() {
            return propertyName;
        }

        @SuppressWarnings("unchecked")
        @Override
        public P getObject() {
            return (P) PropertyResolver.getValue(propertyName,
                    component.getParent().getInnermostModel().getObject());
        }

        @Override
        public void detach() {
            ComponentPropertyModel.this.detach();
        }
    }
}