// Copyright 2004 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.components;
import java.rmi.RemoteException;
import javax.ejb.FinderException;
import org.apache.tapestry.ApplicationRuntimeException;
import org.apache.tapestry.BaseComponent;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.vlib.VirtualLibraryEngine;
import org.apache.tapestry.vlib.Visit;
import org.apache.tapestry.vlib.ejb.Book;
import org.apache.tapestry.vlib.ejb.BorrowException;
import org.apache.tapestry.vlib.ejb.IOperations;
import org.apache.tapestry.vlib.pages.Home;
/**
* Implements the Borrow link that appears on many pages.
*
* <table border=1>
* <tr> <th>Parameter</th> <th>Type</th> <th>Read / Write </th> <th>Required</th> <th>Default</th> <th>Description</th>
* </tr>
*
* <tr>
* <td>book</td>
* <td>{@link Book}</td>
* <td>R</td>
* <td>yes</td>
* <td> </td>
* <td>The book to create a link to.
* </td>
* </tr>
*
* </table>
*
* <p>Informal parameters are not allowed. A body is not allowed.
*
* @author Howard Lewis Ship
* @version $Id: Borrow.java,v 1.9 2004/02/19 17:38:04 hlship Exp $
*
**/
public abstract class Borrow extends BaseComponent
{
public abstract Book getBook();
public boolean isLinkDisabled()
{
Visit visit = (Visit) getPage().getVisit();
if (!visit.isUserLoggedIn())
return true;
// If the user is logged in, they can borrow it if they are
// not already holding it and aren't the owner.
Book book = getBook();
// If the book is not lendable, then disable the link.
if (!book.isLendable())
return true;
// Otherwise, disabled the link if already holding it.
return visit.isLoggedInUser(book.getHolderId());
}
public void borrow(IRequestCycle cycle)
{
Object[] parameters = cycle.getServiceParameters();
Integer bookPK = (Integer) parameters[0];
Visit visit = (Visit) getPage().getVisit();
Home home = (Home) cycle.getPage("Home");
VirtualLibraryEngine vengine = (VirtualLibraryEngine)cycle.getEngine();
int i = 0;
while (true)
{
try
{
IOperations bean = vengine.getOperations();
Book book = bean.borrowBook(bookPK, visit.getUserId());
home.setMessage("Borrowed: " + book.getTitle());
break;
}
catch (BorrowException ex)
{
vengine.presentError(ex.getMessage(), cycle);
return;
}
catch (FinderException ex)
{
throw new ApplicationRuntimeException("Unable to find book or user. ", ex);
}
catch (RemoteException ex)
{
vengine.rmiFailure("Remote exception borrowing book.", ex, i++);
}
}
cycle.activate(home);
}
}