/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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.
*
* Copyright (c) 2001 - 2009 Object Refinery Ltd, Pentaho Corporation and Contributors.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.metadata;
import java.io.IOException;
import java.lang.reflect.Modifier;
import java.net.URL;
import java.util.HashMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.reporting.engine.classic.core.metadata.parser.ExpressionMetaDataCollection;
import org.pentaho.reporting.libraries.resourceloader.Resource;
import org.pentaho.reporting.libraries.resourceloader.ResourceManager;
/**
* Todo: Document Me
*
* @author Thomas Morgner
*/
public class ExpressionRegistry
{
private static final Log logger = LogFactory.getLog(ExpressionRegistry.class);
private static ExpressionRegistry instance;
private HashMap backend;
public static synchronized ExpressionRegistry getInstance()
{
if (instance == null)
{
instance = new ExpressionRegistry();
}
return instance;
}
private ExpressionRegistry()
{
this.backend = new HashMap();
}
public void registerFromXml(final URL expressionMetaSource) throws IOException
{
if (expressionMetaSource == null)
{
throw new NullPointerException("Error: Could not find the expression meta-data description file");
}
try
{
final ResourceManager resourceManager = new ResourceManager();
resourceManager.registerDefaults();
final Resource resource = resourceManager.createDirectly(expressionMetaSource,
ExpressionMetaDataCollection.class);
final ExpressionMetaDataCollection typeCollection = (ExpressionMetaDataCollection) resource.getResource();
final ExpressionMetaData[] types = typeCollection.getExpressionMetaData();
for (int i = 0; i < types.length; i++)
{
final ExpressionMetaData metaData = types[i];
if (metaData != null)
{
registerExpression(metaData);
}
}
}
catch (Exception e)
{
ExpressionRegistry.logger.error("Failed:", e);
throw new IOException("Error: Could not parse the element meta-data description file");
}
}
public void registerExpression(final ExpressionMetaData metaData)
{
if (metaData == null)
{
throw new NullPointerException();
}
final Class type = metaData.getExpressionType();
final int modifiers = type.getModifiers();
if (Modifier.isAbstract(modifiers) || Modifier.isInterface(modifiers))
{
throw new IllegalArgumentException("Expression-Implementation cannot be abstract or an interface.");
}
this.backend.put(type.getName(), metaData);
}
public ExpressionMetaData[] getAllExpressionMetaDatas()
{
return (ExpressionMetaData[]) backend.values().toArray(new ExpressionMetaData[backend.size()]);
}
public boolean isExpressionRegistered(final String identifier)
{
if (identifier == null)
{
throw new NullPointerException();
}
return backend.containsKey(identifier);
}
public ExpressionMetaData getExpressionMetaData(final String identifier) throws MetaDataLookupException
{
if (identifier == null)
{
throw new NullPointerException();
}
final ExpressionMetaData retval = (ExpressionMetaData) backend.get(identifier);
if (retval == null)
{
throw new MetaDataLookupException("Unable to locate metadata for expression type " + identifier);
}
return retval;
}
}