org.eclipse.birt.chart.factory
Interface IDataRowExpressionEvaluator

All Known Implementing Classes:
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

public java.lang.Object evaluate(java.lang.String expression)
Evaluates the expression based on the current row

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().

evaluateGlobal

public 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.

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

public 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

public boolean next()
Moves to the next row.

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

close

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



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