org.opengis.filter.expression
Interface ExpressionVisitor

All Known Implementing Classes:

AbstractExpressionVisitor, AbstractFinderFilterVisitor, AbstractSearchFilterVisitor, ArcSdeSimplifyingFilterVisitor, CapabilitiesFilterSplitter, CollectionFeatureMemberFilterVisitor, ComplexFilterSplitter, ComplexFilterSplitter.CapabilitiesExpressionVisitor, DB2FilterToSQL, DefaultCRSFilterVisitor, DefaultExpressionVisitor, DefaultFilterVisitor, DuplicatingFilterVisitor, ExpressionToText, ExtractBoundsFilterVisitor, FilterAttributeExtractor, FilterToSQL, FilterToSQLSDE, FilterTransformer.FilterTranslator, FilterVisitorExpressionWrapper, FixBBOXFilterVisitor, GeometryEncoderSDE, GeometryTransformationVisitor, H2FilterToSQL, IdCollectorFilterVisitor, IdFinderFilterVisitor, IsFullySupportedFilterVisitor, IsStaticExpressionVisitor, IsSupportedFilterVisitor, MetaBufferEstimator, MySQLFilterToSQL, NullExpressionVisitor, NullFilterVisitor, OracleFilterToSQL, PostgisFilterToSQL, PostgisPSFilterToSql, PostPreProcessFilterSplittingVisitor, PreparedFilterToSQL, PropertyNameResolvingVisitor, ReprojectingFilterVisitor, SimplifyingFilterVisitor, SpatialFilterVisitor, SpatiaLiteFilterToSQL, SQLServerFilterToSQL, StyleAttributeExtractor, StyleAttributeExtractorTruncated, TeradataFilterToSQL, UnmappingFilterVisitor

@Extension
public interface ExpressionVisitor

Visitor with visit methods to be called by Expression.accept(...).

Please note that a generic visit( Expression ) entry point has not been provided, although Expression forms a heirarchy for your convience it is not an open heirarchy. If you need to extend this system please make use of {code Function}, this will allow extention while remaining standards complient.

It is very common for a single instnace to implement both ExpressionVisitor and FilterVisitor.

Since:

GeoAPI 2.0

Author:

Chris Dillard (SYS Technologies)

Method Summary

Object	visit(Add expression, Object extraData)
Object	visit(Divide expression, Object extraData)
Object	visit(Function expression, Object extraData)
Object	visit(Literal expression, Object extraData)
Object	visit(Multiply expression, Object extraData)
Object	visit(NilExpression expression, Object extraData) Used to visit a Expression.NIL, also called for null where an expression is expected.
Object	visit(PropertyName expression, Object extraData)
Object	visit(Subtract expression, Object extraData)

Method Detail

visit

Object visit(NilExpression expression,
             Object extraData)

Used to visit a Expression.NIL, also called for null where an expression is expected.

This is particularly useful when doing data transformations, as an example when using a StyleSymbolizer Expression.NIL can be used to represent the default stroke color.

Parameters:

extraData -

Returns:

implementation specific

visit

Object visit(Add expression,
             Object extraData)

visit

Object visit(Divide expression,
             Object extraData)

visit

Object visit(Function expression,
             Object extraData)

visit

Object visit(Literal expression,
             Object extraData)

visit

Object visit(Multiply expression,
             Object extraData)

visit

Object visit(PropertyName expression,
             Object extraData)

visit

Object visit(Subtract expression,
             Object extraData)