FunctionFactory (Geotools modules 34-SNAPSHOT API)

All Known Implementing Classes:

DefaultFunctionFactory, MBFunctionFactory, PolygonLabelFunctionFactory, ProcessFunctionFactory
```
public interface FunctionFactory
```
Factory interface for filter functions.
The factory provides a list of {#link FunctionName} describing the available functions. Each FunctionName provides details of the name, expected arguments and return type.
Individual functions can be created using a name from this list, along with the required number of arguments and a fallback value.
Prior to GeoTools 2.7 functions were made available as individual factories using FunctionExpression.

Since:

2.7

Author:

Justin Deoliveira (Boundless)

See Also:

Function

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Function`	`function(String name, List<Expression> args, Literal fallback)`	Returns a function with the specified name.
`Function`	`function(Name name, List<Expression> args, Literal fallback)`	Returns a function with the specified name.
`List<FunctionName>`	`getFunctionNames()`	Returns the list of function names the factory provides.

- Method Detail
  - getFunctionNames
```
List<FunctionName> getFunctionNames()
```
    Returns the list of function names the factory provides.
    
    Returns:
    
    A list of function names, possibly empty, never null.
  - function
```
Function function(String name,
                  List<Expression> args,
                  Literal fallback)
```
    Returns a function with the specified name.
    
    Parameters:
    
    name - The name of the function
    
    args - Variable list of expression arguments for the function.
    
    fallback - A fallback literal to use in cases where the function does not exist or can not be created. This argument may be null.
  - function
```
Function function(Name name,
                  List<Expression> args,
                  Literal fallback)
```
    Returns a function with the specified name.
    
    Parameters:
    
    name - The name of the function
    
    args - Variable list of expression arguments for the function.
    
    fallback - A fallback literal to use in cases where the function does not exist or can not be created. This argument may be null.