tapestry/tapestry-examples/Vlib/src/java/org/apache/tapestry/vlib/pages/MyLibrary.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.IRequestCycle;
import org.apache.tapestry.annotations.InjectComponent;
import org.apache.tapestry.annotations.InjectPage;
import org.apache.tapestry.annotations.Persist;
import org.apache.tapestry.vlib.ActivatePage;
import org.apache.tapestry.vlib.components.Browser;
import org.apache.tapestry.vlib.ejb.IBookQuery;
import org.apache.tapestry.vlib.ejb.SortColumn;
import org.apache.tapestry.vlib.ejb.SortOrdering;
import org.apache.tapestry.vlib.services.RemoteCallback;

/**
 * Shows a list of the user's books, allowing books to be editted or even
 * deleted.
 * <p>
 * Note that, unlike elsewhere, book titles do not link to the {@link ViewBook}
 * page. It seems to me there would be a conflict between that behavior and the
 * edit behavior; making the book titles not be links removes the ambiguity over
 * what happens when the book title is clicked (view vs. edit).
 * 
 * @author Howard Lewis Ship
 */

public abstract class MyLibrary extends ActivatePage
{

    @Persist
    public abstract IBookQuery getOwnedQuery();

    public abstract void setOwnedQuery(IBookQuery value);

    @Persist
    public abstract SortColumn getSortColumn();

    public abstract void setSortColumn(SortColumn column);

    @Persist
    public abstract boolean isDescending();

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

    @InjectPage("EditBook")
    public abstract EditBook getEditBook();

    @InjectPage("ConfirmBookDelete")
    public abstract ConfirmBookDelete getConfirmBookDelete();

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

    public void activate()
    {
        runQuery();

        getRequestCycle().activate(this);
    }

    public void requery(IRequestCycle cycle)
    {
        runQuery();
    }

    private void runQuery()
    {
        final Integer userId = getVisitState().getUserId();
        final SortOrdering ordering = new SortOrdering(getSortColumn(),
                isDescending());

        RemoteCallback<Integer> callback = new RemoteCallback()
        {

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

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

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

        int count = getRemoteTemplate().execute(callback,
                "Error accessing owned books.");

        Browser browser = getBrowser();

        if (count != browser.getResultCount())
            browser.initializeForResultCount(count);
    }

    /**
     * Listener invoked to allow a user to edit a book.
     */

    public void editBook(Integer bookId)
    {
        getEditBook().beginEdit(bookId);
    }

    /**
     * Listener invoked to allow a user to delete a book.
     */

    public void deleteBook(Integer bookId)
    {
        getConfirmBookDelete().selectBook(bookId);
    }

}