org.geotools.filter.visitor

Class IsStaticExpressionVisitor

Object

IsStaticExpressionVisitor

All Implemented Interfaces:

ExpressionVisitor

public class IsStaticExpressionVisitor
extends Object
implements ExpressionVisitor

Check if an expression is static (ie does not contain a PropertyName expression).

This visitor will "short-circuit" the moment it finds a PropertyName expression and will not need to visit the entire data structure.

Example:

 if( filter.accepts( IsStaticExpressionVisitor.VISITOR, null ) ){
     Color color = expression.evaulate( null, Color.class );
     ...
 }
 

Author:

Jody

Field Summary

Fields

Modifier and Type	Field and Description
static IsStaticExpressionVisitor	VISITOR

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	IsStaticExpressionVisitor() visit each expression and check that they are static

Method Summary

Modifier and Type	Method and Description
Boolean	visit(Add expression, Object data) visit each expression and check that they are static
Boolean	visit(Divide expression, Object data) visit each expression and check that they are static
Boolean	visit(Function expression, Object data) Visit each parameter and check if they are static
Boolean	visit(Literal expression, Object data) Literal expressions are always static.
Boolean	visit(Multiply expression, Object data) visit each expression and check that they are static.
Boolean	visit(NilExpression expression, Object data) visit each expression and check that they are static
Boolean	visit(PropertyName expression, Object data) If even a single PropertyName is found in the expression the expression is not static.
Boolean	visit(Subtract expression, Object data) visit each expression and check that they are static.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

VISITOR

public static final IsStaticExpressionVisitor VISITOR

Constructor Detail

IsStaticExpressionVisitor

protected IsStaticExpressionVisitor()

visit each expression and check that they are static

Method Detail

visit

public Boolean visit(NilExpression expression,
                     Object data)

visit each expression and check that they are static

Specified by:

visit in interface ExpressionVisitor

Returns:

implementation specific

visit

public Boolean visit(Add expression,
                     Object data)

visit each expression and check that they are static

Specified by:

visit in interface ExpressionVisitor

visit

public Boolean visit(Divide expression,
                     Object data)

visit each expression and check that they are static

Specified by:

visit in interface ExpressionVisitor

visit

public Boolean visit(Function expression,
                     Object data)

Visit each parameter and check if they are static

Specified by:

visit in interface ExpressionVisitor

visit

public Boolean visit(Literal expression,
                     Object data)

Literal expressions are always static.

Specified by:

visit in interface ExpressionVisitor

Returns:

true

visit

public Boolean visit(Multiply expression,
                     Object data)

visit each expression and check that they are static.

Specified by:

visit in interface ExpressionVisitor

Returns:

true if getExpression1 and getExpression2 are static

visit

public Boolean visit(PropertyName expression,
                     Object data)

If even a single PropertyName is found in the expression the expression is not static.

Specified by:

visit in interface ExpressionVisitor

Returns:

false

visit

public Boolean visit(Subtract expression,
                     Object data)

visit each expression and check that they are static.

Specified by:

visit in interface ExpressionVisitor

Returns:

true if getExpression1 and getExpression2 are static