tapestry/tapestry-examples/Vlib/src/java/org/apache/tapestry/vlib/pages/ViewPerson.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// 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.apache.tapestry.vlib.pages;

import java.rmi.RemoteException;

import org.apache.tapestry.IExternalPage;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.annotations.InjectComponent;
import org.apache.tapestry.annotations.Meta;
import org.apache.tapestry.annotations.Persist;
import org.apache.tapestry.event.PageBeginRenderListener;
import org.apache.tapestry.event.PageEvent;
import org.apache.tapestry.vlib.VlibPage;
import org.apache.tapestry.vlib.components.Browser;
import org.apache.tapestry.vlib.ejb.IBookQuery;
import org.apache.tapestry.vlib.ejb.Person;
import org.apache.tapestry.vlib.ejb.SortColumn;
import org.apache.tapestry.vlib.ejb.SortOrdering;
import org.apache.tapestry.vlib.services.RemoteCallback;

/**
 * Displays the book inventory list for a single
 * {@link org.apache.tapestry.vlib.ejb.IPerson}, showing what books are owned
 * by the person, who has them borrowed, etc. If the user is logged in, then
 * books can be borrowed from this page as well.
 * 
 * @author Howard Lewis Ship
 */
@Meta( { "page-type=Search", "anonymous-access=true" })
public abstract class ViewPerson extends VlibPage implements IExternalPage,
        PageBeginRenderListener
{

    public abstract Integer getPersonId();

    @Persist
    public abstract void setPersonId(Integer personId);

    public abstract void setPerson(Person value);

    public abstract Person getPerson();

    @Persist
    public abstract IBookQuery getQuery();

    public abstract void setQuery(IBookQuery value);

    @Persist
    public abstract SortColumn getSortColumn();

    public abstract void setSortColumn(SortColumn sortColumn);

    @Persist
    public abstract boolean isDescending();

    @InjectComponent("browser")
    public abstract Browser getBrowser();

    public void finishLoad()
    {
        setSortColumn(SortColumn.TITLE);
    }

    /**
     * Invoked by the external service to being viewing the identified person.
     */

    public void activateExternalPage(Object[] parameters, IRequestCycle cycle)
    {
        Integer personId = (Integer) parameters[0];

        setPersonId(personId);

        // Force the query to be re-run when the person changes.

        int count = runQuery();

        getBrowser().initializeForResultCount(count);
    }

    public void requery(IRequestCycle cycle)
    {
        int count = runQuery();

        if (getBrowser().getResultCount() != count)
            getBrowser().setResultCount(count);
    }

    private int runQuery()
    {
        final Integer personId = getPersonId();
        final SortOrdering ordering = new SortOrdering(getSortColumn(),
                isDescending());

        RemoteCallback<Integer> callback = new RemoteCallback()
        {

            public Integer doRemote()
                throws RemoteException
            {
                IBookQuery query = getQuery();

                if (query == null)
                {
                    query = getBookQuerySource().newQuery();
                    setQuery(query);
                }

                try
                {
                    return query.ownerQuery(personId, ordering);
                }
                catch (RemoteException ex)
                {
                    setQuery(null);
                    throw ex;
                }
            }
        };

        return getRemoteTemplate().execute(callback,
                "Error executing owner query.");
    }

    public void pageBeginRender(PageEvent event)
    {
        Person person = getPerson();

        if (person == null)
        {
            person = getRemoteTemplate().getPerson(getPersonId());

            setPerson(person);
        }
    }

}