Interface FunctionFactory

  • 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 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.