org.pentaho.reporting.engine.classic.core.modules.misc.bsf
Class BSFExpression

java.lang.Object
  org.pentaho.reporting.engine.classic.core.function.AbstractExpression
      org.pentaho.reporting.engine.classic.core.modules.misc.bsf.BSFExpression

All Implemented Interfaces:

Serializable, Cloneable, Expression

public class BSFExpression
extends AbstractExpression

An expression that uses the Bean scripting framework to perform a scripted calculation.

Author:

Thomas Morgner

See Also:

Serialized Form

Constructor Summary

BSFExpression()
Default constructor, create a new BeanShellExpression.

Method Summary

Object	clone() Clones the expression and reinitializes the script.
String	getExpression() Returns the script that gets evaluated every time the getValue() method is called.
String	getLanguage() Returns the programming language, in which the interpreter work.
String	getScript() Returns the script.
Object	getValue() Evaluates the defined expression.
void	setExpression(String expression) Sets the script that should be executed.
void	setLanguage(String language) Defines the programming language of the script and expression.
void	setScript(String script) Defines the script.

Methods inherited from class org.pentaho.reporting.engine.classic.core.function.AbstractExpression

getDataRow, getDependencyLevel, getInstance, 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

Constructor Detail

BSFExpression

public BSFExpression()

Default constructor, create a new BeanShellExpression.

Method Detail

getValue

public Object getValue()

Evaluates the defined expression. If an exception or an evaluation error occures, the evaluation returns null and the error is logged. The current datarow and a copy of the expressions properties are set to script-internal variables. Changes to the properties will not alter the expressions original properties and will be lost when the evaluation is finished.

Expressions do not maintain a state and no assumptions about the order of evaluation can be made.

Returns:

the evaluated value or null.

clone

public Object clone()
             throws CloneNotSupportedException

Clones the expression and reinitializes the script.

Specified by:

clone in interface Expression

Overrides:

clone in class AbstractExpression

Returns:

a clone of the expression.

Throws:

CloneNotSupportedException - this should never happen.

getExpression

public String getExpression()

Returns the script that gets evaluated every time the getValue() method is called.

Returns:

the script.

setExpression

public void setExpression(String expression)

Sets the script that should be executed. Whats in the script depends on what langage is selected.

Parameters:

expression - the script.

getLanguage

public String getLanguage()

Returns the programming language, in which the interpreter work.

Returns:

the programming language, which must be one of the supported BSF-Languages.

setLanguage

public void setLanguage(String language)

Defines the programming language of the script and expression.

Parameters:

language - the programming language of the script.

getScript

public String getScript()

Returns the script. The script is a predefined piece of code that gets executed once. It can (and should) be used to perform global initializations and to define functions.

Returns:

the script (can be null).

setScript

public void setScript(String script)

Defines the script. The script is a predefined piece of code that gets executed once. It can (and should) be used to perform global initializations and to define functions.

Parameters:

script - an initialization script.