org.geotools.filter
Class FallbackFunction
java.lang.Object
org.geotools.filter.expression.ExpressionAbstract
org.geotools.filter.DefaultExpression
org.geotools.filter.FunctionExpressionImpl
org.geotools.filter.FallbackFunction
- All Implemented Interfaces:
- Factory, ExpressionType, FunctionExpression, org.opengis.filter.expression.Expression, org.opengis.filter.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 org.geotools.filter.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 |
Fields inherited from interface org.opengis.filter.expression.Expression |
NIL |
Constructor Summary |
protected |
FallbackFunction(java.lang.String name,
java.util.List params,
org.opengis.filter.expression.Literal fallback)
|
Method Summary |
java.lang.Object |
evaluate(java.lang.Object object)
This method checks if the object is an instance of Feature and
if so, calls through to #evaluate(Feature) . |
java.lang.Object |
evaluate(java.lang.Object object,
java.lang.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 org.geotools.filter.FunctionExpressionImpl |
accept, equals, getArgs, getExpression, getFallbackValue, getImplementationHints, getName, getParameters, getType, setArgs, setFallbackValue, setName, setParameters, toString |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
FallbackFunction
protected FallbackFunction(java.lang.String name,
java.util.List params,
org.opengis.filter.expression.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
- Specified by:
getArgCount
in class FunctionExpressionImpl
- Returns:
- the number of args.
evaluate
public java.lang.Object evaluate(java.lang.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 org.opengis.filter.expression.Expression
- Overrides:
evaluate
in class DefaultExpression
evaluate
public java.lang.Object evaluate(java.lang.Object object,
java.lang.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 org.opengis.filter.expression.Expression
- Overrides:
evaluate
in class ExpressionAbstract
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