org.eclipse.birt.chart.factory
Interface IDataRowExpressionEvaluator

All Known Subinterfaces:

IGroupedDataRowExpressionEvaluator

All Known Implementing Classes:

AbstractGroupedDataRowExpressionEvaluator, DataRowExpressionEvaluatorAdapter

public interface IDataRowExpressionEvaluator

This interface provide expression evaluations of any string expression based on a row context. This is usually associated with an underlying resultset.

Method Summary

void	close() Closes the underlying resultset.
java.lang.Object	evaluate(java.lang.String expression) Evaluates the expression based on the current row
java.lang.Object	evaluateGlobal(java.lang.String expression) Deprecated. Not used anymore. use evaluate(String) instead.
boolean	first() Moves to the first row.
boolean	next() Moves to the next row.

Method Detail

evaluate

java.lang.Object evaluate(java.lang.String expression)

Evaluates the expression based on the current row

Parameters:

A - String expression

Returns:

An Object representing the evaluated expression. The Object must be of a type String, Number, Date, Calendar, or it will be evaluated as a String using toString(). If there is any BirtException being caught by evaluation, the return value will be the caught BirtException.

evaluateGlobal

java.lang.Object evaluateGlobal(java.lang.String expression)

Deprecated. Not used anymore. use evaluate(String) instead.

Evaluates the global expressions which are not associated with the data rows.

Parameters:

A - String expression

Returns:

An Object representing the evaluated expression. The Object must be of a type String, Number, Date, Calendar, or it will be evaluated as a String using toString().

first

boolean first()

Moves to the first row. Optional if already positioned on the first row when passed to Generator.bindData()

Returns:

true if the cursor is on a valid row; false if there are no rows in the result set

next

boolean next()

Moves to the next row.

Returns:

False if the last row has been reached. True otherwise.

close

void close()

Closes the underlying resultset. This is optional (it can be a no-op if the close is handled externally or not needed).