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

java.lang.Object
  org.pentaho.reporting.engine.classic.core.function.AbstractExpression

All Implemented Interfaces:

Serializable, Cloneable, Expression

Direct Known Subclasses:

AbstractCompareExpression, AbstractFunction, AverageExpression, BSFExpression, BSHExpression, CapitalizeStringExpression, ColumnAggregationExpression, ConvertToDateExpression, ConvertToNumberExpression, DateCutExpression, DateExpression, DateSpanExpression, FormulaExpression, GetDataRowValueExpression, IsEmptyDataExpression, IsEmptyExpression, IsExportTypeExpression, IsNegativeExpression, IsNullExpression, IsPositiveExpression, MapIndirectExpression, MapStringExpression, MessageFormatExpression, PercentageExpression, ResourceBundleLookupExpression, ResourceMesssageFormatExpression, SubStringExpression, SurveyScaleExpression, TextFormatExpression, TokenizeStringExpression, ToLowerCaseStringExpression, ToUpperCaseStringExpression, URLEncodeExpression

public abstract class AbstractExpression
extends Object
implements Expression

An abstract base class for implementing new report expressions.

Expressions are stateless functions which have access to the report's DataRow. All expressions are named and the defined names have to be unique within the report's expressions, functions and fields of the datasource. Expressions are configured using properties.

Author:

Thomas Morgner

See Also:

Serialized Form

Method Summary

Object	clone() Clones the expression.
DataRow	getDataRow() Returns the current DataRow.
int	getDependencyLevel() Returns the dependency level for the expression (controls evaluation order for expressions and functions).
Expression	getInstance() Return a completly separated copy of this function.
String	getName() Returns the name of the expression.
org.pentaho.reporting.libraries.base.config.Configuration	getReportConfiguration() Returns the report's current configuration.
ResourceBundleFactory	getResourceBundleFactory() Returns the resource-bundle factory of the report.
ExpressionRuntime	getRuntime() Returns the ExpressionRune used in this expression.
boolean	isActive() Deprecated. The Active-Flag is no longer evaluated. We always assume it to be true.
boolean	isDeepTraversing() Checks whether this expression is a deep-traversing expression.
boolean	isPreserve() Checks whether this expression's last value is preserved after the expression goes out of scope.
void	setActive(boolean active) Deprecated. All expressions are always active. This method has no effect anymore.
void	setDependencyLevel(int level) Sets the dependency level for the expression.
void	setName(String name) Sets the name of the expression.
void	setPreserve(boolean preserve) Defines, whether this expression's last value is preserved after the expression goes out of scope.
void	setRuntime(ExpressionRuntime runtime) Defines the ExpressionRune used in this expression.

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.function.Expression

getValue

Method Detail

getName

public String getName()

Returns the name of the expression.

Specified by:

getName in interface Expression

Returns:

the name.

setName

public void setName(String name)

Sets the name of the expression.

The name should be unique among:

• the functions and expressions for the report;
• the columns in the report's TableModel;

This allows the expression to be referenced by name from any report element.

You should not change the name of an expression once it has been added to the report's expression collection.

Specified by:

setName in interface Expression

Parameters:

name - the name (null not permitted).

isActive

public final boolean isActive()

Deprecated. The Active-Flag is no longer evaluated. We always assume it to be true.

Returns true if this expression contains "auto-active" content and should be called by the system regardless of whether this expression is referenced in the DataRow.

Specified by:

isActive in interface Expression

Returns:

true as all expressions are always evaluated now.

setActive

public final void setActive(boolean active)

Deprecated. All expressions are always active. This method has no effect anymore.

Defines, whether the expression is an active expression. This method has no effect anymore.

Parameters:

active - a flag.

getDependencyLevel

public int getDependencyLevel()

Returns the dependency level for the expression (controls evaluation order for expressions and functions).

Specified by:

getDependencyLevel in interface Expression

Returns:

the level.

setDependencyLevel

public void setDependencyLevel(int level)

Sets the dependency level for the expression.

The dependency level controls the order of evaluation for expressions and functions. Higher level expressions are evaluated before lower level expressions. Any level in the range 0 to Integer.MAX_VALUE is allowed. Negative values are reserved for system functions (printing and layouting).

Specified by:

setDependencyLevel in interface Expression

Parameters:

level - the level (must be greater than or equal to 0).

getDataRow

public DataRow getDataRow()

Returns the current DataRow.

Specified by:

getDataRow in interface Expression

Returns:

the data row.

clone

public Object clone()
             throws CloneNotSupportedException

Clones the expression. The expression should be reinitialized after the cloning.

Expressions maintain no state, cloning is done at the beginning of the report processing to disconnect the expression from any other object space.

Specified by:

clone in interface Expression

Overrides:

clone in class Object

Returns:

a clone of this expression.

Throws:

CloneNotSupportedException - this should never happen.

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

Returns:

a copy of this function.

getResourceBundleFactory

public ResourceBundleFactory getResourceBundleFactory()

Description copied from interface: Expression

Returns the resource-bundle factory of the report. This factory encapsulates the Locale and allows to create a resource-bundle in a implementation-independent way.

Specified by:

getResourceBundleFactory in interface Expression

Returns:

the resource-bundle factory.

getReportConfiguration

public org.pentaho.reporting.libraries.base.config.Configuration getReportConfiguration()

Description copied from interface: Expression

Returns the report's current configuration.

Specified by:

getReportConfiguration in interface Expression

Returns:

the configuration of the report.

setRuntime

public void setRuntime(ExpressionRuntime runtime)

Defines the ExpressionRune used in this expression. The ExpressionRuntime is set before the expression receives events or gets evaluated and is unset afterwards. Do not hold references on the runtime or you will create memory-leaks.

Specified by:

setRuntime in interface Expression

Parameters:

runtime - the runtime information for the expression

getRuntime

public ExpressionRuntime getRuntime()

Returns the ExpressionRune used in this expression. The ExpressionRuntime is set before the expression receives events or gets evaluated and is unset afterwards. Do not hold references on the runtime or you will create memory-leaks.

Specified by:

getRuntime in interface Expression

Returns:

the runtime information for the expression

isDeepTraversing

public boolean isDeepTraversing()

Checks whether this expression is a deep-traversing expression. Deep-traversing expressions receive events from all sub-reports. This returns false by default, as ordinary expressions have no need to be deep-traversing.

Specified by:

isDeepTraversing in interface Expression

Returns:

false.

isPreserve

public boolean isPreserve()

Checks whether this expression's last value is preserved after the expression goes out of scope.

Specified by:

isPreserve in interface Expression

Returns:

true, if the expression's last value is preserved, false otherwise.

setPreserve

public void setPreserve(boolean preserve)

Defines, whether this expression's last value is preserved after the expression goes out of scope.

Parameters:

preserve - true, if the expression's last value is preserved, false otherwise.