/*
* 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 - 2013 Object Refinery Ltd, Pentaho Corporation and Contributors.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.states;
import org.pentaho.reporting.engine.classic.core.DataRow;
import org.pentaho.reporting.engine.classic.core.filter.DataSource;
import org.pentaho.reporting.engine.classic.core.filter.DataTarget;
/**
* This is the connection-proxy to the various data sources contained in the elements. During report processing the
* report states get cloned while the elements remain uncloned. The DataRowConnector connects the DataRowBackend (which
* contains the data) with the stateless elements.
*
* @author Thomas Morgner
*/
public final class DataRowConnector implements DataRow {
/**
* The data row backend.
*/
private DataRow dataRow;
/**
* Default constructor.
*/
public DataRowConnector() {
}
/**
* Returns the assigned data row backend.
*
* @return the currently assigned DataRowBackend for this DataRowConnector.
*/
public DataRow getDataRowBackend() {
return dataRow;
}
public String[] getColumnNames() {
if ( dataRow == null ) {
throw new IllegalStateException( "Not connected" );
}
return dataRow.getColumnNames();
}
/**
* Sets the data row backend for this DataRowConnector. The backend actually contains the data which will be queried,
* while this DataRowConnector is simply a proxy forwarding all requests to the backend.
*
* @param dataRow
* the data row backend
*/
public void setDataRowBackend( final DataRow dataRow ) {
this.dataRow = dataRow;
}
/**
* Returns the value of the column, function or expression using its name.
*
* @param col
* the column, function or expression index.
* @return The column, function or expression value.
* @throws java.lang.IllegalStateException
* if there is no backend connected
*/
public Object get( final String col ) {
if ( dataRow == null ) {
throw new IllegalStateException( "Not connected" );
}
return dataRow.get( col );
}
/**
* Queries the last datasource in the chain of targets and filters.
* <p/>
* The last datasource is used to feed data into the data processing chain. The result of this computation is
* retrieved by the element using the registered datasource to query the queue.
*
* @param e
* the data target.
* @return The last DataSource in the chain.
* @deprecated no longer used.
*/
public static DataSource getLastDatasource( final DataTarget e ) {
if ( e == null ) {
throw new NullPointerException();
}
DataSource s = e.getDataSource();
while ( s instanceof DataTarget ) {
final DataTarget tgt = (DataTarget) s;
s = tgt.getDataSource();
}
return s;
}
/**
* Returns a string describing the object.
*
* @return The string.
*/
public String toString() {
if ( dataRow == null ) {
return "org.pentaho.reporting.engine.classic.core.states.DataRowConnector=Not Connected";
}
return "org.pentaho.reporting.engine.classic.core.states.DataRowConnector=Connected:" + dataRow;
}
public boolean isChanged( final String name ) {
return dataRow.isChanged( name );
}
}