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public interface IAggrFunction
Each instance of IAggrFunction defines an aggregation function which can be used in BIRT. All user defined aggregations should implement this interface.
Field Summary | |
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static int |
RUNNING_AGGR
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static int |
SUMMARY_AGGR
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Method Summary | |
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int |
getDataType()
get the aggregation data type. |
java.lang.Object |
getDefaultValue()
Returns the default aggregation result if the data series that the accumulator of this aggregation function requires is empty. |
java.lang.String |
getDescription()
Gets the functional description of this aggregation function. |
java.lang.String |
getDisplayName()
Gets the display name that identifies the aggregation function in the report designer user interface. |
java.lang.String |
getName()
Gets the name that identifies the aggregate function represented by this class. |
int |
getNumberOfPasses()
Returns the number of passes over the data series that the accumulator of this aggregate requires. |
IParameterDefn[] |
getParameterDefn()
Gets information about the parameters that this aggregate function takes as an array of IParameterDefn values. |
int |
getType()
Gets the type of the Aggregation. |
boolean |
isDataOrderSensitive()
To indicate whether the data series is order sensitive for the aggregation value. |
Accumulator |
newAccumulator()
Creates a new instance of the accumulator for this aggregation. |
Field Detail |
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static final int SUMMARY_AGGR
static final int RUNNING_AGGR
Method Detail |
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java.lang.String getName()
java.lang.String getDisplayName()
java.lang.String getDescription()
int getType()
int getDataType()
IParameterDefn[] getParameterDefn()
The length of the returned array is the number of runtime parameters that this aggregate function takes. Note that this number excludes the optional filter and group parameters common to all aggregate functions. Those two parameters are handled by the DtE.
If the n'th element in the array is true, it means that the n'th parameter is a dynamic parameter which needs to be evaluated at each row. Otherwise the parameter is static, and it only needs to be evaluated once at the start of the accumulation
For example, the Total.movingAve function is defined as
movingAve( expr, window [, filter [, group ]] )
The expr parameter is the data being aggregated over and should be
calculated at every row. The window parameter on the other hand must be a
fixed number for each series of data. Therefore the class implementing
the movingAve function should return boolean array [true, false].
int getNumberOfPasses()
java.lang.Object getDefaultValue()
boolean isDataOrderSensitive()
Accumulator newAccumulator()
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