AggregationRegistry (Dataflow Library Distribution Project 8.0.0-98 API)

java.lang.Object
- com.pervasive.datarush.aggregations.AggregationRegistry

```
public class AggregationRegistry
extends Object
```
Stores a list of aggregations registered by the AggregationProvider, and provides a method for calling those aggregations.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Aggregation`	`getAggregation(String name, ScalarValuedFunction[] arguments)`	Invoke an Aggregation by name, using the supplied arguments.
`FunctionDescription`	`getFunctionDescription(String name, int argCount)`	Create a FunctionDescription for a given aggregation.
`Collection<FunctionDescription>`	`getFunctionDescriptions()`	Return a list of descriptions of all available aggregations.
`Map<String,Collection<FunctionDescription>>`	`getFunctionDescriptionsByCategory()`	Returns a list of descriptions of all available aggregations, organized by category.
`static AggregationRegistry`	`getInstance()`	Get an instance of the AggregationRegistry.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - getInstance
```
public static AggregationRegistry getInstance()
```
    Get an instance of the AggregationRegistry.
    
    Returns:
    
    An instance of the AggregationRegistry
  - getAggregation
```
public Aggregation getAggregation(String name,
                                  ScalarValuedFunction[] arguments)
```
    Invoke an Aggregation by name, using the supplied arguments.
    
    Parameters:
    
    name - The registered name of the aggregation.
    
    arguments - The arguments to pass to the aggregation.
    
    Returns:
    
    The Aggregation.
  - getFunctionDescriptions
```
public Collection<FunctionDescription> getFunctionDescriptions()
```
    Return a list of descriptions of all available aggregations.
    
    Returns:
  - getFunctionDescriptionsByCategory
```
public Map<String,Collection<FunctionDescription>> getFunctionDescriptionsByCategory()
```
    Returns a list of descriptions of all available aggregations, organized by category.
    
    Returns:
  - getFunctionDescription
```
public FunctionDescription getFunctionDescription(String name,
                                                  int argCount)
```
    Create a FunctionDescription for a given aggregation.
    
    Parameters:
    
    name - The name of the aggregation
    
    argCount - The number of arguments the aggregation takes
    
    Returns:
    
    The FunctionDescription of the aggregation