org.geotools.filter.visitor
Class SimplifyingFilterVisitor
Object
DuplicatingFilterVisitor
SimplifyingFilterVisitor
- All Implemented Interfaces:
- ExpressionVisitor, FilterVisitor
public class SimplifyingFilterVisitor
- extends DuplicatingFilterVisitor
Takes a filter and returns a simplified, equivalent one. At the moment the filter simplifies out
Filter.INCLUDE
and Filter.EXCLUDE
and deal with FID filter validation.
FID filter validation is meant to wipe out non valid feature ids from Id
filters. This is
so in order to avoid sending feature ids down to DataStores that are not valid as per the
specific FeatureType fid structure. Since this is structure is usually DataStore specific, some
times being a strategy based on how the feature type primary key is generated, fid validation is
abstracted out to the SimplifyingFilterVisitor.FIDValidator
interface so when a DataStore is about to send a query
down to the backend it van provide this visitor with a validator specific for the feature type
fid structure being queried.
By default all feature ids are valid. DataStores that want non valid fids to be wiped out should
set a SimplifyingFilterVisitor.FIDValidator
through the setFIDValidator(FIDValidator)
method.
- Since:
- 2.5.x
- Author:
- Andrea Aime - OpenGeo, Gabriel Roldan (OpenGeo)
- Module:
modules/library/main (gt-main.jar)
Nested Class Summary |
static interface |
SimplifyingFilterVisitor.FIDValidator
Defines a simple means of assessing whether a feature id in an Id filter is
structurally valid and hence can be send down to the backend with confidence it will not
cause trouble, the most common one being filtering by pk number even if the type name prefix
does not match. |
static class |
SimplifyingFilterVisitor.RegExFIDValidator
A FID validator that matches the fids with a given regular expression to determine the fid's
validity. |
static class |
SimplifyingFilterVisitor.TypeNameDotNumberFidValidator
A convenient fid validator for the common case of a feature id being a composition of a
{@code . |
Methods inherited from class DuplicatingFilterVisitor |
getFactory, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visitNullFilter |
Methods inherited from class Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
ANY_FID_VALID
public static final SimplifyingFilterVisitor.FIDValidator ANY_FID_VALID
- A 'null-object' fid validator that assumes any feature id in an
Id
filter is valid
SimplifyingFilterVisitor
public SimplifyingFilterVisitor()
setFIDValidator
public void setFIDValidator(SimplifyingFilterVisitor.FIDValidator validator)
visit
public Object visit(And filter,
Object extraData)
- Specified by:
visit
in interface FilterVisitor
- Overrides:
visit
in class DuplicatingFilterVisitor
visit
public Object visit(Or filter,
Object extraData)
- Specified by:
visit
in interface FilterVisitor
- Overrides:
visit
in class DuplicatingFilterVisitor
visit
public Object visit(Id filter,
Object extraData)
- Uses the current
SimplifyingFilterVisitor.FIDValidator
to wipe out illegal feature ids from the returned
filters.
- Specified by:
visit
in interface FilterVisitor
- Overrides:
visit
in class DuplicatingFilterVisitor
- Returns:
- a filter containing only valid fids as per the current
SimplifyingFilterVisitor.FIDValidator
, may be
Filter.EXCLUDE
if none matches or the filter is already empty
visit
public Object visit(Not filter,
Object extraData)
- Specified by:
visit
in interface FilterVisitor
- Overrides:
visit
in class DuplicatingFilterVisitor
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