org.geotools.filter.visitor
Class EnvironmentVariableResolver

java.lang.Object
  org.geotools.filter.visitor.EnvironmentVariableResolver

public class EnvironmentVariableResolver

extends java.lang.Object

Finds instances of specific environment variable expressions within filters and composite expressins and replaces them with simple literals.

Author:

James Macgill, Penn State

Constructor Summary

EnvironmentVariableResolver()
Empty constructor

Method Summary

boolean	needsResolving(Filter f) Test supplied filter to see if it contains any EnvironmentVariable expressions
Expression	resolve(Expression exp, double mapScale) Find all instances of MapScaleDenominator and replace them with the a literal expression for the provided map scale.
Filter	resolve(Filter filter, double mapScale) Find all instances of MapScaleDenominator and replace them with the a literal expression for the provided map scale.

Methods inherited from class java.lang.Object

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

Constructor Detail

EnvironmentVariableResolver

public EnvironmentVariableResolver()

Empty constructor

Method Detail

resolve

public Filter resolve(Filter filter,
                      double mapScale)
               throws org.geotools.filter.parser.ParseException

Find all instances of MapScaleDenominator and replace them with the a literal expression for the provided map scale. The passed in filter is NOT modifed by calls to this method.

Parameters:

filter - The Filter to check for MapScaleDenominator Environment Variables

Returns:

A Filter with the map scale env variable replaced by literals

Throws:

org.geotools.filter.parser.ParseException

resolve

public Expression resolve(Expression exp,
                          double mapScale)
                   throws org.geotools.filter.parser.ParseException

Find all instances of MapScaleDenominator and replace them with the a literal expression for the provided map scale. The passed in filter is NOT modifed by calls to this method.

Parameters:

exp - The Expression to check for MapScaleDenominator Environment Variables

Returns:

An Epression with the map scale env variable replaced by literals

Throws:

org.geotools.filter.parser.ParseException

needsResolving

public boolean needsResolving(Filter f)

Test supplied filter to see if it contains any EnvironmentVariable expressions