net.sf.jasperreports.engine
Interface JRVariable

All Superinterfaces:

Cloneable, JRCloneable

All Known Implementing Classes:

JRBaseVariable, JRDesignVariable, JRFillVariable

public interface JRVariable
extends JRCloneable

An interface for implementing classes that deal with report variables. This interface defines constants for names of built-in variables and for reset, increment and calculation types.

When declaring a report group, the engine will automatically create a count variable that will calculate the number of records that make up the current group (number of records processed between group ruptures). The name for this variable comes from the name of the group it corresponds to, suffixed with the "_COUNT" sequence. It can be used like any other report variable, in any report expression (even in the current group expression like you can see done in the "BreakGroup" of the jasper sample).

Version:

$Id: JRVariable.java 5180 2012-03-29 13:23:12Z teodord $

Author:

Teodor Danciu (teodord@users.sourceforge.net)

Field Summary

static String	COLUMN_COUNT This variable contains the number of records that were processed when generating the current column.
static String	COLUMN_NUMBER Built-in variable containing the current column number.
static String	PAGE_COUNT Built-in variable containing the number of records that were processed when generating the current page.
static String	PAGE_NUMBER Built-in variable containing the current page number.
static String	REPORT_COUNT Built-in variable that contains the total number of records read from the datasource.

Method Summary

CalculationEnum	getCalculationValue() Gets the variable calculation type.
JRExpression	getExpression() Returns the main expression for this variable.
Class<?>	getIncrementerFactoryClass() Returns the class of the incrementer factory used for choosing the right incrementer for the variable value.
String	getIncrementerFactoryClassName() Returns the string name of the variable value class.
JRGroup	getIncrementGroup() Returns the group whose break triggers the variable increment.
IncrementTypeEnum	getIncrementTypeValue() Gets the variable increment type.
JRExpression	getInitialValueExpression() Returns the initial value expression for this variable.
String	getName() Returns the name of the variable.
JRGroup	getResetGroup() Returns the group whose break triggers the variable reset.
ResetTypeEnum	getResetTypeValue() Gets the variable reset type.
Class<?>	getValueClass() Returns the class of the variable value.
String	getValueClassName() Returns the string name of the variable value class.
boolean	isSystemDefined() Returns true if the variable calculation type is system defined.

Methods inherited from interface net.sf.jasperreports.engine.JRCloneable

clone

Field Detail

REPORT_COUNT

static final String REPORT_COUNT

Built-in variable that contains the total number of records read from the datasource. After finishing iterating throught the datasource, it will contain the total number of records that were processed.

See Also:

Constant Field Values

PAGE_COUNT

static final String PAGE_COUNT

Built-in variable containing the number of records that were processed when generating the current page.

See Also:

Constant Field Values

COLUMN_COUNT

static final String COLUMN_COUNT

This variable contains the number of records that were processed when generating the current column.

See Also:

Constant Field Values

PAGE_NUMBER

static final String PAGE_NUMBER

Built-in variable containing the current page number. At the end of the report filling process, it will contain the total number of pages for the resulting document.

See Also:

Constant Field Values

COLUMN_NUMBER

static final String COLUMN_NUMBER

Built-in variable containing the current column number.

See Also:

Constant Field Values

Method Detail

getName

String getName()

Returns the name of the variable. Since all variables are stored in a map, the variable names are the keys in the map.

Returns:

a string containing the variable name

getValueClass

Class<?> getValueClass()

Returns the class of the variable value. Any class is allowed as long as it is in the classpath at compile and run time.

Returns:

a Class instance representing the variable value class

getValueClassName

String getValueClassName()

Returns the string name of the variable value class.

getIncrementerFactoryClass

Class<?> getIncrementerFactoryClass()

Returns the class of the incrementer factory used for choosing the right incrementer for the variable value.

Returns:

the Class instance of the incrementer factory

See Also:

JRIncrementer, JRIncrementerFactory

getIncrementerFactoryClassName

String getIncrementerFactoryClassName()

Returns the string name of the variable value class.

getResetTypeValue

ResetTypeEnum getResetTypeValue()

Gets the variable reset type.

Returns:

a value representing one of the reset type constants in ResetTypeEnum

getIncrementTypeValue

IncrementTypeEnum getIncrementTypeValue()

Gets the variable increment type.

Returns:

a value representing one of the reset type constants in IncrementTypeEnum

getCalculationValue

CalculationEnum getCalculationValue()

Gets the variable calculation type.

Returns:

a value representing one of the calculation type constants in CalculationEnum

isSystemDefined

boolean isSystemDefined()

Returns true if the variable calculation type is system defined.

See Also:

CalculationEnum.SYSTEM

getExpression

JRExpression getExpression()

Returns the main expression for this variable. The expression must be numeric for certain calculation types.

Returns:

a JRExpression instance containing the expression.

getInitialValueExpression

JRExpression getInitialValueExpression()

Returns the initial value expression for this variable. The expression must be numeric for certain calculation types.

Returns:

a JRExpression instance containing the initial expression.

getResetGroup

JRGroup getResetGroup()

Returns the group whose break triggers the variable reset. Only used when getResetTypeValue() returns ResetTypeEnum.GROUP.

getIncrementGroup

JRGroup getIncrementGroup()

Returns the group whose break triggers the variable increment. Only used when getIncrementTypeValue() returns ResetTypeEnum.GROUP.