RolePropertyDescriptor.java

/*
 * Copyright 2010 Instituto Superior Tecnico
 * 
 *      https://fenix-ashes.ist.utl.pt/
 * 
 *   This file is part of the vaadin-framework.
 *
 *   The vaadin-framework Infrastructure is free software: you can
 *   redistribute it and/or modify it under the terms of the GNU Lesser General
 *   Public License as published by the Free Software Foundation, either version
 *   3 of the License, or (at your option) any later version.*
 *
 *   vaadin-framework is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with vaadin-framework. If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package pt.ist.vaadinframework.data.metamodel;

import java.beans.IntrospectionException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;

import org.apache.commons.lang.WordUtils;

import pt.ist.fenixframework.DomainObject;
import pt.ist.fenixframework.dml.Role;

import com.vaadin.data.Property.ConversionException;

/**
 * @author Pedro Santos (pedro.miguel.santos@ist.utl.pt)
 * 
 */
public class RolePropertyDescriptor implements PropertyDescriptor {
    private final String propertyId;

    private transient Method reader;

    private transient Method writer;

    private final boolean required;

    // if the relation has * on other type this implies a collection of elements
    // of this type.
    private Class<? extends DomainObject> elementType;

    private final Role role;

    private final Class<? extends DomainObject> type;

    private final Class<? extends DomainObject> returnType;

    public RolePropertyDescriptor(Role role, Class<? extends DomainObject> type) throws IntrospectionException,
            SecurityException, NoSuchMethodException, ClassNotFoundException {
        this.propertyId = role.getName();
        required = role.getMultiplicityLower() > 0;
        this.role = role;
        this.type = type;
        calc();
        returnType = (Class<? extends DomainObject>) reader.getReturnType();
    }

    private void calc() throws IntrospectionException, SecurityException, NoSuchMethodException, ClassNotFoundException {
        if (role.getMultiplicityUpper() == 1) {
            java.beans.PropertyDescriptor property = new java.beans.PropertyDescriptor(role.getName(), type);
            reader = property.getReadMethod();
            writer = property.getWriteMethod();
        } else {
            reader = type.getMethod("get" + WordUtils.capitalize(role.getName()) + "Set");
            elementType = (Class<? extends DomainObject>) Class.forName(role.getType().getFullName());
        }
    }

    /**
     * @see pt.ist.vaadinframework.data.metamodel.PropertyDescriptor#getPropertyId()
     */
    @Override
    public String getPropertyId() {
        return propertyId;
    }

    /**
     * @see pt.ist.vaadinframework.data.metamodel.PropertyDescriptor#getPropertyType()
     */
    @Override
    public Class<? extends DomainObject> getPropertyType() {
        return returnType;
    }

    @Override
    public Class<? extends DomainObject> getCollectionElementType() {
        return elementType;
    }

    /**
     * @see pt.ist.vaadinframework.data.metamodel.PropertyDescriptor#getDefaultValue()
     */
    @Override
    public Object getDefaultValue() {
        if (Boolean.class.isAssignableFrom(getPropertyType())) {
            return Boolean.FALSE;
        }
        if (Collection.class.isAssignableFrom(getPropertyType())) {
            return Collections.emptySet();
        }
        return null;
    }

    /**
     * @see pt.ist.vaadinframework.data.metamodel.PropertyDescriptor#isCollection()
     */
    @Override
    public boolean isCollection() {
        return Collection.class.isAssignableFrom(getPropertyType());
    }

    /**
     * @see pt.ist.vaadinframework.data.metamodel.PropertyDescriptor#isRequired()
     */
    @Override
    public boolean isRequired() {
        return required;
    }

    /**
     * @see pt.ist.vaadinframework.data.metamodel.PropertyDescriptor#read(java.lang.Object)
     */
    @Override
    public Object read(Object host) throws ModelIntroscpectionException {
        try {
            if (reader == null) {
                calc();
            }
            return reader.invoke(host);
        } catch (Throwable e) {
            throw new ModelIntroscpectionException(e);
        }
    }

    /**
     * @see pt.ist.vaadinframework.data.metamodel.PropertyDescriptor#write(java.lang.Object, java.lang.Object)
     */
    @Override
    public void write(Object host, Object newValue) throws ConversionException {
        try {
            if (reader == null) {
                calc();
            }
            if (writer != null) {
                writer.invoke(host, newValue);
            } else {
                Set<?> set = (Set<?>) reader.invoke(host);
                set.clear();
                set.addAll((Collection) newValue);
            }
        } catch (IllegalArgumentException e) {
            throw new ConversionException(e);
        } catch (IllegalAccessException e) {
            throw new ConversionException(e);
        } catch (InvocationTargetException e) {
            throw new ConversionException(e);
        } catch (SecurityException e) {
            throw new ConversionException(e);
        } catch (IntrospectionException e) {
            throw new ConversionException(e);
        } catch (NoSuchMethodException e) {
            throw new ConversionException(e);
        } catch (ClassNotFoundException e) {
            throw new ConversionException(e);
        }
    }

}