/*
* 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.filter;
import org.pentaho.reporting.engine.classic.core.ReportElement;
import org.pentaho.reporting.engine.classic.core.function.ExpressionRuntime;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;
import java.text.Format;
/**
* The base class for filters that format data. Data is received from a DataSource and formatted. The data source might
* be a field in the TableModel or a report function, or even another format filter (since filters implement the
* DataSource interface).
* <p/>
* Formating is done by a java.text.Format object. This filter will always return a String object on getValue().
* <p/>
* If the formater does not understand the object returned by the defined datasource, the defined null value is
* returned.
* <p/>
* The nullValue is set to "-" by default.
*
* @author Thomas Morgner
*/
public class FormatFilter implements DataFilter, RawDataSource {
/**
* The format used to create the string representation of the data.
*/
private Format format;
/**
* The datasource from where the data is obtained.
*/
private DataSource datasource;
/**
* The string used to represent null.
*/
private String nullvalue;
/**
* A string holding the formatted result.
*/
private transient String cachedResult;
/**
* The cached raw-value. This value is used to compare the incomming value with the cached result.
*/
private transient Object cachedValue;
/**
* The cached Formatter.
*/
private transient Format cachedFormat;
/**
* Default constructor.
*/
public FormatFilter() {
nullvalue = null;
}
/**
* Clears all cached values and forces a complete recomputation of all formattings.
*/
protected void invalidateCache() {
cachedFormat = null;
cachedValue = null;
cachedResult = null;
}
/**
* Sets the format for the filter.
*
* @param format
* The format.
* @throws NullPointerException
* if the given format is null
*/
public void setFormatter( final Format format ) {
if ( format == null ) {
throw new NullPointerException();
}
this.format = format;
}
/**
* Returns the format for the filter.
*
* @return The format.
*/
public Format getFormatter() {
return this.format;
}
/**
* Returns the formatted string. The value is read using the data source given and formated using the formatter of
* this object. The formating is guaranteed to completly form the object to an string or to return the defined
* NullValue.
* <p/>
* If format, datasource or object are null, the NullValue is returned.
*
* @param runtime
* the expression runtime that is used to evaluate formulas and expressions when computing the value of this
* filter.
* @param element
* @return The formatted value.
*/
public Object getValue( final ExpressionRuntime runtime, final ReportElement element ) {
final Format f = getFormatter();
if ( f == null ) {
return getNullValue();
}
final DataSource ds = getDataSource();
if ( ds == null ) {
return getNullValue();
}
final Object o = ds.getValue( runtime, element );
if ( o == null ) {
return getNullValue();
}
if ( cachedResult != null && ( cachedFormat != f ) && ObjectUtilities.equal( cachedValue, o ) ) {
return cachedResult;
}
try {
cachedResult = f.format( o );
} catch ( IllegalArgumentException e ) {
cachedResult = getNullValue();
}
cachedFormat = f;
cachedValue = o;
return cachedResult;
}
/**
* Sets the value that will be displayed if the data source supplies a null value.
*
* @param nullvalue
* The string.
*/
public void setNullValue( final String nullvalue ) {
if ( nullvalue == null ) {
throw new NullPointerException();
}
this.nullvalue = nullvalue;
}
/**
* Returns the string representing a null value from the data source.
*
* @return The string.
*/
public String getNullValue() {
return nullvalue;
}
/**
* Returns the data source for the filter.
*
* @return The data source.
*/
public DataSource getDataSource() {
return datasource;
}
/**
* Sets the data source.
*
* @param ds
* The data source.
*/
public void setDataSource( final DataSource ds ) {
if ( ds == null ) {
throw new NullPointerException();
}
this.datasource = ds;
}
/**
* Clones the filter.
*
* @return a clone.
* @throws CloneNotSupportedException
* this should never happen.
*/
public FormatFilter clone() throws CloneNotSupportedException {
final FormatFilter f = (FormatFilter) super.clone();
if ( datasource != null ) {
f.datasource = datasource.clone();
}
if ( format != null ) {
f.format = (Format) format.clone();
if ( cachedFormat == format ) {
f.cachedFormat = f.format;
}
}
return f;
}
public Object getRawValue( final ExpressionRuntime runtime, final ReportElement element ) {
return datasource.getValue( runtime, element );
}
public FormatSpecification getFormatString( final ExpressionRuntime runtime, final ReportElement element,
FormatSpecification formatSpecification ) {
if ( datasource instanceof RawDataSource ) {
final RawDataSource rds = (RawDataSource) datasource;
return rds.getFormatString( runtime, element, formatSpecification );
}
if ( formatSpecification == null ) {
formatSpecification = new FormatSpecification();
}
formatSpecification.redefine( FormatSpecification.TYPE_UNDEFINED, null );
return formatSpecification;
}
}