Package 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.
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Method Summary
Modifier and TypeMethodDescriptionvoidclose()Closes the underlying resultset.Evaluates the expression based on the current rowevaluateGlobal(String expression) Deprecated.Not used anymore.booleanfirst()Moves to the first row.booleannext()Moves to the next row.
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Method Details
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evaluate
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.
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evaluateGlobal
Deprecated.Not used anymore. useevaluate(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().
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first
boolean first()Moves to the first row. Optional if already positioned on the first row when passed to Generator.bindData()- Returns:
trueif the cursor is on a valid row;falseif there are no rows in the result set
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next
boolean next()Moves to the next row.- Returns:
- False if the last row has been reached. True otherwise.
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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).
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