// 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.pages;
import java.rmi.RemoteException;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.html.BasePage;
import org.apache.tapestry.vlib.IMessageProperty;
import org.apache.tapestry.vlib.VirtualLibraryEngine;
import org.apache.tapestry.vlib.components.Browser;
import org.apache.tapestry.vlib.ejb.IBookQuery;
import org.apache.tapestry.vlib.ejb.MasterQueryParameters;
import org.apache.tapestry.vlib.ejb.SortColumn;
import org.apache.tapestry.vlib.ejb.SortOrdering;
/**
* Runs queries and displays matches.
*
* @author Howard Lewis Ship
* @version $Id: BookMatches.java,v 1.11 2004/02/19 17:37:48 hlship Exp $
**/
public abstract class BookMatches extends BasePage
{
private Browser _browser;
public void finishLoad()
{
_browser = (Browser) getComponent("browser");
}
public abstract IBookQuery getBookQuery();
public abstract void setBookQuery(IBookQuery bookQuery);
public abstract SortColumn getSortColumn();
public abstract boolean isDescending();
public abstract MasterQueryParameters getQueryParameters();
public abstract void setQueryParameters(MasterQueryParameters queryParameters);
/**
* Invoked by the {@link Home} page to perform a query.
*
**/
public void performQuery(MasterQueryParameters parameters, IRequestCycle cycle)
{
setQueryParameters(parameters);
int count = executeQuery();
if (count == 0)
{
IMessageProperty page = (IMessageProperty) cycle.getPage();
page.setMessage(getMessage("no-matches"));
return;
}
_browser.initializeForResultCount(count);
cycle.activate(this);
}
public void requery(IRequestCycle cycle)
{
int count = executeQuery();
if (count != _browser.getResultCount())
_browser.initializeForResultCount(count);
}
private int executeQuery()
{
VirtualLibraryEngine vengine = (VirtualLibraryEngine) getEngine();
MasterQueryParameters parameters = getQueryParameters();
SortOrdering ordering = new SortOrdering(getSortColumn(), isDescending());
int i = 0;
while (true)
{
try
{
IBookQuery query = getBookQuery();
if (query == null)
{
query = vengine.createNewQuery();
setBookQuery(query);
}
return query.masterQuery(parameters, ordering);
}
catch (RemoteException ex)
{
vengine.rmiFailure("Remote exception processing query.", ex, i++);
setBookQuery(null);
}
}
}
}