Package org.geotools.mbstyle.function

Class DefaultIfNullFunction

Object

ExpressionAbstract

FunctionImpl

DefaultIfNullFunction

All Implemented Interfaces:

Expression, Function

public class DefaultIfNullFunction
extends FunctionImpl

Function that takes an input value, and a default value. If the input value is null (or evaluating it raises an exception), returns the default value; otherwise, returns the input value.

Field Summary

Fields

Modifier and Type	Field	Description
static final FunctionName	NAME

Fields inherited from class FunctionImpl

functionName

Fields inherited from interface Expression

NIL

Constructor Summary

Constructors

Constructor	Description
DefaultIfNullFunction()

Method Summary

Modifier and Type	Method	Description
Object	evaluate(Object object)	Default implementation simply returns the fallbackValue.
<T> T	evaluate(Object object, Class<T> context)	Default implementation delegates handling of context conversion to Converters utility class.

Methods inherited from class FunctionImpl

accept, dispatchArguments, equals, functionName, getFallbackValue, getFunctionName, getName, getParameters, getParameterValue, getParameterValue, hashCode, setFallbackValue, setName, setParameters, toString

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

NAME

public static final FunctionName NAME

Constructor Details

DefaultIfNullFunction

public DefaultIfNullFunction()

Method Details

evaluate

public Object evaluate(Object object)

Description copied from class: FunctionImpl

Default implementation simply returns the fallbackValue.

Please override this method to produce a value based on the provided arguments.

Specified by:

evaluate in interface Expression

Overrides:

evaluate in class FunctionImpl

Parameters:

object - Object being evaluated; often a Feature

Returns:

value for the provided object

evaluate

public <T> T evaluate(Object object,
 Class<T> context)

Description copied from class: ExpressionAbstract

Default implementation delegates handling of context conversion to Converters utility class.

Subclasses are expected to make use of the Converters utility class (as the easiest way to provide value morphing in conformance with the Filter specification).

Specified by:

evaluate in interface Expression

Overrides:

evaluate in class ExpressionAbstract

Type Parameters:

T - The type of the returned object.

Parameters:

object - The object to evaluate the expression against.

context - The type of the resulting value of the expression.

Returns:

Evaluates the given expression based on the content of the given object an an instance of context.