org.pentaho.reporting.engine.classic.core.function
Class TotalGroupSumFunction

java.lang.Object
  extended by org.pentaho.reporting.engine.classic.core.function.AbstractExpression
      extended by org.pentaho.reporting.engine.classic.core.function.AbstractFunction
          extended by org.pentaho.reporting.engine.classic.core.function.TotalGroupSumFunction
All Implemented Interfaces:
Serializable, Cloneable, EventListener, ReportListener, AggregationFunction, Expression, FieldAggregationFunction, Function

public class TotalGroupSumFunction
extends AbstractFunction
implements FieldAggregationFunction

A report function that calculates the sum of one field (column) from the Data-Row. This function produces a global total. The total sum of the group is known when the group processing starts and the report is not performing a prepare-run. The sum is calculated in the prepare run and recalled in the printing run.

The function can be used in two ways:

This function expects its input values to be either java.lang.Number instances or Strings that can be parsed to java.lang.Number instances using a java.text.DecimalFormat.

The function undestands two parameters, the field parameter is required and denotes the name of an ItemBand-field which gets summed up.

The parameter group denotes the name of a group. When this group is started, the counter gets reseted to null. This parameter is optional.

Author:
Thomas Morgner
See Also:
Serialized Form

Constructor Summary
TotalGroupSumFunction()
          Constructs a new function.
 
Method Summary
 String getField()
          Returns the field used by the function.
 String getGroup()
          Returns the name of the group to be totalled.
 Expression getInstance()
          Return a completly separated copy of this function.
 Object getValue()
          Return the current function value.
 void groupStarted(ReportEvent event)
          Receives notification that a group has started.
 void itemsAdvanced(ReportEvent event)
          Receives notification that a row of data is being processed.
 void reportInitialized(ReportEvent event)
          Receives notification that the report has started.
 void setField(String field)
          Sets the field name for the function.
 void setGroup(String group)
          Defines the name of the group to be totalled.
 
Methods inherited from class org.pentaho.reporting.engine.classic.core.function.AbstractFunction
groupFinished, itemsFinished, itemsStarted, reportDone, reportFinished, reportStarted
 
Methods inherited from class org.pentaho.reporting.engine.classic.core.function.AbstractExpression
clone, getDataRow, getDependencyLevel, getName, getReportConfiguration, getResourceBundleFactory, getRuntime, isActive, isDeepTraversing, isPreserve, setActive, setDependencyLevel, setName, setPreserve, setRuntime
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.pentaho.reporting.engine.classic.core.event.ReportListener
groupFinished, itemsFinished, itemsStarted, reportDone, reportFinished, reportStarted
 
Methods inherited from interface org.pentaho.reporting.engine.classic.core.function.Expression
clone, getDataRow, getDependencyLevel, getName, getReportConfiguration, getResourceBundleFactory, getRuntime, isActive, isDeepTraversing, isPreserve, setDependencyLevel, setName, setRuntime
 

Constructor Detail

TotalGroupSumFunction

public TotalGroupSumFunction()
Constructs a new function.

Initially the function has no name...be sure to assign one before using the function.

Method Detail

reportInitialized

public void reportInitialized(ReportEvent event)
Receives notification that the report has started.

Specified by:
reportInitialized in interface ReportListener
Overrides:
reportInitialized in class AbstractFunction
Parameters:
event - the event.

groupStarted

public void groupStarted(ReportEvent event)
Receives notification that a group has started.

Specified by:
groupStarted in interface ReportListener
Overrides:
groupStarted in class AbstractFunction
Parameters:
event - the event.

itemsAdvanced

public void itemsAdvanced(ReportEvent event)
Receives notification that a row of data is being processed.

Specified by:
itemsAdvanced in interface ReportListener
Overrides:
itemsAdvanced in class AbstractFunction
Parameters:
event - the event.

getGroup

public String getGroup()
Returns the name of the group to be totalled.

Specified by:
getGroup in interface AggregationFunction
Returns:
the group name.

setGroup

public void setGroup(String group)
Defines the name of the group to be totalled. If the name is null, all groups are totalled.

Specified by:
setGroup in interface AggregationFunction
Parameters:
group - the group name.

getValue

public Object getValue()
Return the current function value.

The value depends (obviously) on the function implementation. For example, a page counting function will return the current page number.

Specified by:
getValue in interface Expression
Returns:
The value of the function.

getField

public String getField()
Returns the field used by the function. The field name corresponds to a column name in the report's data-row.

Specified by:
getField in interface FieldAggregationFunction
Returns:
The field name.

setField

public void setField(String field)
Sets the field name for the function. The field name corresponds to a column name in the report's data-row.

Specified by:
setField in interface FieldAggregationFunction
Parameters:
field - the field name.

getInstance

public Expression getInstance()
Return a completly separated copy of this function. The copy does no longer share any changeable objects with the original function.

Specified by:
getInstance in interface Expression
Overrides:
getInstance in class AbstractExpression
Returns:
a copy of this function.