Package org.geotools.filter.function
Class Collection_UniqueFunction
- Object
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- ExpressionAbstract
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- DefaultExpression
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- FunctionExpressionImpl
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- Collection_UniqueFunction
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- All Implemented Interfaces:
Expression
,Function
,FunctionExpression
,Factory
public class Collection_UniqueFunction extends FunctionExpressionImpl
Calculates the unique value of an attribute for a given FeatureCollection and Expression.- Since:
- 2.2M2
- Author:
- Cory Horner
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Field Summary
Fields Modifier and Type Field Description static FunctionName
NAME
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Fields inherited from class FunctionExpressionImpl
fallback, functionName, name, params
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Fields inherited from interface Expression
NIL
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Constructor Summary
Constructors Constructor Description Collection_UniqueFunction()
Creates a new instance of Collection_UniqueFunction
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Object
evaluate(Object feature)
Subclass should override, default implementation returns null.void
setExpression(Expression e)
void
setParameters(List<Expression> args)
The provided arguments are evaulated with respect to the FeatureCollection.-
Methods inherited from class FunctionExpressionImpl
accept, equals, functionName, getExpression, getFallbackValue, getFunctionName, getImplementationHints, getName, getParameters, hashCode, setFallbackValue, toString
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Methods inherited from class DefaultExpression
isAttributeExpression, isExpression, isFunctionExpression, isGeometryExpression, isLiteralExpression, isMathExpression
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Methods inherited from class ExpressionAbstract
evaluate
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Methods inherited from interface Expression
evaluate
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Field Detail
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NAME
public static FunctionName NAME
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Method Detail
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setParameters
public void setParameters(List<Expression> args)
The provided arguments are evaulated with respect to the FeatureCollection.For an aggregate function (like unique) please use the WFS mandated XPath syntax to refer to featureMember content.
To refer to all 'X':
featureMember/asterisk/X
- Specified by:
setParameters
in interfaceFunctionExpression
- Overrides:
setParameters
in classFunctionExpressionImpl
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evaluate
public Object evaluate(Object feature)
Description copied from class:ExpressionAbstract
Subclass should override, default implementation returns null.- Specified by:
evaluate
in interfaceExpression
- Overrides:
evaluate
in classFunctionExpressionImpl
- Returns:
- default implementation returns null
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setExpression
public void setExpression(Expression e)
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