groovy-core/src/main/org/codehaus/groovy/binding/ModelBinding.java

/*
 * Copyright 2007 the original author or authors.
 *
 * 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.codehaus.groovy.binding;

import groovy.lang.GroovyObjectSupport;
import groovy.lang.ReadOnlyPropertyException;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * @author <a href="mailto:shemnon@yahoo.com">Danno Ferrin</a>
 * @version $Revision$
 * @since Groovy 1.1
 */
public class ModelBinding extends GroovyObjectSupport implements BindingUpdatable {

    Object model;
    boolean bound;
    

    final Map/*<String, PropertyBinding>*/ propertyBindings = new HashMap/*<String, PropertyBinding>*/();
    final List/*<FullBinding>*/ generatedBindings = new ArrayList/*<FullBinding>*/();

    public ModelBinding(Object model) {
        this.model = model;
    }

    public Object getModel() {
        return model;
    }

    public synchronized void setModel(Object model) {
        // should we use a finer grained lock than this?

        this.model = model;
        //TODO see if bound, mark if so
        unbind();
        Iterator iter = propertyBindings.values().iterator();
        while (iter.hasNext()) {
            ((PropertyBinding)iter.next()).setBean(model);
        }
        //TODO only bind if already bound
        rebind();
        update();
    }

    public Object getProperty(String property) {
        PropertyBinding pb;
        synchronized (propertyBindings) {
            // should we verify the property is valid?
            Object o = propertyBindings.get(property);
            if (o == null) {
                o = new ModelBindingPropertyBinding(model, property);
                propertyBindings.put(property, o);
            }
            pb = (PropertyBinding)o;
        }
        FullBinding fb = pb.createBinding(pb, null);
        if (bound) {
            fb.bind();
        }
        return fb;
    }

    public void setProperty(String property, Object value) {
        throw new ReadOnlyPropertyException(property, model.getClass());
    }

    public void bind() {
        synchronized (generatedBindings) {
            if (!bound) {
                bound = true;
                Iterator iter = generatedBindings.iterator();
                while (iter.hasNext()) {
                    ((FullBinding)iter.next()).bind();
                    // should we trap exceptions and do an each?
                }
            }
        }
    }

    public void unbind() {
        synchronized (generatedBindings) {
            if (bound) {
                bound = false;
                Iterator iter = generatedBindings.iterator();
                while (iter.hasNext()) {
                    ((FullBinding)iter.next()).unbind();
                    // should we trap exceptions and do an each?
                }
            }
        }
    }

    public void rebind() {
        synchronized (generatedBindings) {
            if (bound) {
                Iterator iter = generatedBindings.iterator();
                while (iter.hasNext()) {
                    ((FullBinding)iter.next()).rebind();
                    // should we trap exceptions and do an each?
                }
            }
        }
    }

    public void update() {
        synchronized (generatedBindings) {
            Iterator iter = generatedBindings.iterator();
            while (iter.hasNext()) {
                ((FullBinding)iter.next()).update();
                // should we trap exceptions and do an each?
            }
        }
    }

    public void reverseUpdate() {
        synchronized (generatedBindings) {
            Iterator iter = generatedBindings.iterator();
            while (iter.hasNext()) {
                ((FullBinding)iter.next()).reverseUpdate();
                // should we trap exceptions and do an each?
            }
        }
    }

    class ModelBindingPropertyBinding extends PropertyBinding {
        public ModelBindingPropertyBinding(Object bean, String propertyName) {
            super(bean, propertyName);
        }

        public FullBinding createBinding(SourceBinding source, TargetBinding target) {
            FullBinding fb = super.createBinding(source, target);
            generatedBindings.add(fb);
            return fb;
        }
    }

}