org.geotools.filter.function
Class PropertyExistsFunction

Object
  extended by ExpressionAbstract
      extended by DefaultExpression
          extended by FunctionExpressionImpl
              extended by PropertyExistsFunction
All Implemented Interfaces:
Factory, ExpressionType, FunctionExpression, Expression, Function

public class PropertyExistsFunction
extends FunctionExpressionImpl

A new function to check if a property exists.

Module:
modules/library/cql (gt-cql.jar)

Field Summary
 
Fields inherited from class FunctionExpressionImpl
fallback, name, params
 
Fields inherited from class DefaultExpression
expressionType, permissiveConstruction
 
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
 
Constructor Summary
PropertyExistsFunction()
           
 
Method Summary
 boolean equals(Object obj)
           
 Object evaluate(Object bean)
          This method checks if the object is an instance of Feature and if so, calls through to #evaluate(Feature).
 Object evaluate(SimpleFeature feature)
          Returns a value for this expression.
 int getArgCount()
          Gets the number of arguments that are set.
 String toString()
          Creates a String representation of this Function with the function name and the arguments.
 
Methods inherited from class FunctionExpressionImpl
accept, getArgs, getExpression, getFallbackValue, getImplementationHints, getName, getParameters, getType, setArgs, setFallbackValue, setName, setParameters
 
Methods inherited from class DefaultExpression
accept, getValue, isAttributeExpression, isExpression, isFunctionExpression, isGeometryExpression, isLiteralExpression, isMathExpression, isMathExpression
 
Methods inherited from class ExpressionAbstract
eval, eval, evaluate
 
Methods inherited from class Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface Expression
accept, getValue
 
Methods inherited from interface Expression
evaluate
 
Methods inherited from interface Expression
evaluate
 

Constructor Detail

PropertyExistsFunction

public PropertyExistsFunction()
Method Detail

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 Object evaluate(SimpleFeature feature)
Description copied from class: DefaultExpression
Returns a value for this expression. If the expression is an attribute expression then the attribute of the feature should be returned. If a literal then the feature is ignored, the literal is returned as it has no relation to the feature.

Overrides:
evaluate in class DefaultExpression
Parameters:
feature - Specified feature to use when returning value.
Returns:
Boolean.TRUE if the feature's FeatureType contains an attribute named as the property name passed as this function argument, Boolean.FALSE otherwise.

evaluate

public Object evaluate(Object bean)
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
Returns:
Boolean.TRUE if the Class of the object passed as argument defines a property names as the property name passed as this function argument, following the standard Java Beans naming conventions for getters. Boolean.FALSE otherwise.

toString

public String toString()
Description copied from class: FunctionExpressionImpl
Creates a String representation of this Function with the function name and the arguments. The String created should be good for most subclasses

Overrides:
toString in class FunctionExpressionImpl

equals

public boolean equals(Object obj)
Overrides:
equals in class FunctionExpressionImpl


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