org.geotools.filter.function
Class Collection_CountFunction
Object
ExpressionAbstract
DefaultExpression
FunctionExpressionImpl
Collection_CountFunction
- All Implemented Interfaces:
- Factory, ExpressionType, FunctionExpression, Expression, Function
public class Collection_CountFunction
- extends FunctionExpressionImpl
Calculates the count value of an attribute for a given FeatureCollection and
Expression.
- Since:
- 2.2M2
- Author:
- Cory Horner
- Module:
modules/library/main (gt-main.jar)
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 |
Fields inherited from interface Expression |
NIL |
Fields inherited from interface Expression |
NIL |
Method Summary |
Object |
evaluate(Object feature)
This method checks if the object is an instance of Feature and
if so, calls through to #evaluate(Feature) . |
int |
getArgCount()
Gets the number of arguments that are set. |
void |
setParameters(List args)
The provided arguments are evaulated with respect to the
FeatureCollection. |
Methods inherited from class FunctionExpressionImpl |
accept, equals, getArgs, getExpression, getFallbackValue, getImplementationHints, getName, getParameters, getType, setArgs, setFallbackValue, setName, toString |
Methods inherited from interface Expression |
evaluate |
Methods inherited from interface Expression |
evaluate |
Collection_CountFunction
public Collection_CountFunction()
- Creates a new instance of Collection_CountFunction
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.
setParameters
public void setParameters(List args)
- The provided arguments are evaulated with respect to the
FeatureCollection.
For an aggregate function (like count) please use the WFS mandated XPath
syntax to refer to featureMember content.
To refer to all 'X': featureMember/asterisk/X
- Specified by:
setParameters
in interface FunctionExpression
- Overrides:
setParameters
in class FunctionExpressionImpl
- Parameters:
args
- DOCUMENT ME!
- Throws:
IllegalArgumentException
- DOCUMENT ME!
evaluate
public Object evaluate(Object feature)
- 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
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