org.geotools.filter
Class FallbackFunction
Object
ExpressionAbstract
DefaultExpression
FunctionExpressionImpl
FallbackFunction
- All Implemented Interfaces:
- Factory, ExpressionType, FunctionExpression, Expression, Function
public class FallbackFunction
- extends FunctionExpressionImpl
A placeholder class used to track a function the user requested
that is not supported by our java implementation.
This can be used to construct expressions that are to be executed
by another systems (say as SQL or as a WFS request).
- Author:
- Jody Garnett
Fields inherited from interface ExpressionType |
ATTRIBUTE, ATTRIBUTE_DOUBLE, ATTRIBUTE_GEOMETRY, ATTRIBUTE_INTEGER, ATTRIBUTE_STRING, ATTRIBUTE_UNDECLARED, FUNCTION, LITERAL_DOUBLE, LITERAL_GEOMETRY, LITERAL_INTEGER, LITERAL_LONG, LITERAL_STRING, LITERAL_UNDECLARED, MATH_ADD, MATH_DIVIDE, MATH_MULTIPLY, MATH_SUBTRACT |
Method Summary |
Object |
evaluate(Object object)
This method checks if the object is an instance of Feature and
if so, calls through to #evaluate(Feature) . |
Object |
evaluate(Object object,
Class context)
Default implementation delegates handling of context
conversion to Value utility class. |
int |
getArgCount()
Gets the number of arguments that are set. |
Methods inherited from class FunctionExpressionImpl |
accept, equals, functionName, getArgs, getExpression, getFallbackValue, getFunctionName, getImplementationHints, getName, getParameters, getType, setArgs, setFallbackValue, setName, setParameters, toString |
FallbackFunction
public FallbackFunction(String name,
List params,
Literal fallback)
FallbackFunction
public FallbackFunction(Name name,
List params,
Literal fallback)
getArgCount
public int getArgCount()
- Description copied from class:
FunctionExpressionImpl
- Gets the number of arguments that are set.
- Specified by:
getArgCount
in interface FunctionExpression
- Overrides:
getArgCount
in class FunctionExpressionImpl
- Returns:
- the number of args.
evaluate
public Object evaluate(Object object)
- Description copied from class:
DefaultExpression
- This method checks if the object is an instance of
Feature
and
if so, calls through to #evaluate(Feature)
. This is done
to maintain backwards compatability with previous version of Expression api
which depended on Feature. If the object is not an instance of feature
the super implementation is called.
- Specified by:
evaluate
in interface Expression
- Overrides:
evaluate
in class DefaultExpression
evaluate
public Object evaluate(Object object,
Class context)
- Description copied from class:
ExpressionAbstract
- Default implementation delegates handling of context
conversion to Value utility class.
Subclasses are expected to make use of the Value utility class
(as the easiest way to provide value morphing in confirmance with
the Filter specification).
- Specified by:
evaluate
in interface Expression
- Overrides:
evaluate
in class ExpressionAbstract
- 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
.
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