/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2007-2011, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.filter.expression;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.Pointer;
import org.apache.commons.jxpath.ri.JXPathContextReferenceImpl;
import org.geotools.factory.Hints;
import org.opengis.feature.IllegalAttributeException;
import org.geotools.feature.xpath.AttributeNodePointer;
import org.geotools.feature.xpath.AttributeNodePointerFactory;
import org.geotools.filter.expression.PropertyAccessor;
import org.geotools.filter.expression.PropertyAccessorFactory;
import org.opengis.feature.Attribute;
import org.opengis.feature.ComplexAttribute;
import org.opengis.feature.Feature;
import org.opengis.feature.GeometryAttribute;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.type.AttributeDescriptor;
import org.opengis.feature.type.AttributeType;
import org.opengis.feature.type.ComplexType;
import org.opengis.feature.type.FeatureType;
import org.opengis.feature.type.GeometryDescriptor;
import org.opengis.feature.type.PropertyDescriptor;
import org.xml.sax.helpers.NamespaceSupport;
import com.vividsolutions.jts.geom.Geometry;
/**
* Creates a namespace aware property accessor for ISO Features.
* <p>
* The created accessor handles a small subset of xpath expressions, a non-nested "name" which
* corresponds to a feature attribute, and "@id", corresponding to the feature id.
* </p>
* <p>
* THe property accessor may be run against {@link org.geotools.feature.Feature}, or against
* {@link org.geotools.feature.FeatureType}. In the former case the feature property value is
* returned, in the latter a descriptor is returned (in case of "@" attributes, a Name is returned
* or null if the attribute doesn't exist - can be used to validate an x-path!) .
* </p>
*
* @author Justin Deoliveira (The Open Planning Project)
* @author Gabriel Roldan (Axios Engineering)
*
*
*
*
*
* @source $URL$
*/
public class FeaturePropertyAccessorFactory implements PropertyAccessorFactory {
static {
// unfortunatley, jxpath only works against concreate classes
// JXPathIntrospector.registerDynamicClass(DefaultFeature.class,
// FeaturePropertyHandler.class);
JXPathContextReferenceImpl.addNodePointerFactory(new AttributeNodePointerFactory());
}
/** Single instnace is fine - we are not stateful */
static PropertyAccessor ATTRIBUTE_ACCESS = new FeaturePropertyAccessor();
static PropertyAccessor DEFAULT_GEOMETRY_ACCESS = new DefaultGeometryFeaturePropertyAccessor();
static PropertyAccessor FID_ACCESS = new FidFeaturePropertyAccessor();
public PropertyAccessor createPropertyAccessor(Class type, String xpath, Class target,
Hints hints) {
if (SimpleFeature.class.isAssignableFrom(type)) {
/*
* This class is not intended for use with SimpleFeature and causes problems when
* discovered via SPI and used by code expecting SimpleFeature behaviour. In particular
* WMS styling code may fail when this class is present. See GEOS-3525.
*/
return null;
}
if (xpath == null)
return null;
if (!ComplexAttribute.class.isAssignableFrom(type)
&& !ComplexType.class.isAssignableFrom(type)
&& !AttributeDescriptor.class.isAssignableFrom(type))
return null;
if("".equals(xpath))
//if ("".equals(xpath) && target == Geometry.class)
return DEFAULT_GEOMETRY_ACCESS;
// check for fid access
if (xpath.matches("@(\\w+:)?id"))
return FID_ACCESS;
// check for simple property access
// if (xpath.matches("(\\w+:)?(\\w+)")) {
NamespaceSupport namespaces = null;
if (hints != null) {
namespaces = (NamespaceSupport) hints
.get(FeaturePropertyAccessorFactory.NAMESPACE_CONTEXT);
}
if (namespaces == null) {
return ATTRIBUTE_ACCESS;
} else {
return new FeaturePropertyAccessor(namespaces);
}
// }
// return null;
}
/**
* Access to Feature Identifier.
*
* @author Jody Garnett (Refractions Research)
*/
static class FidFeaturePropertyAccessor implements PropertyAccessor {
public boolean canHandle(Object object, String xpath, Class target) {
// we only work against feature, not feature type
return object instanceof Attribute && xpath.matches("@(\\w+:)?id");
}
public Object get(Object object, String xpath, Class target) {
Attribute feature = (Attribute) object;
return feature.getIdentifier().toString();
}
public void set(Object object, String xpath, Object value, Class target) {
throw new org.opengis.feature.IllegalAttributeException(null, value,
"feature id is immutable");
}
}
static class DefaultGeometryFeaturePropertyAccessor implements PropertyAccessor {
public boolean canHandle(Object object, String xpath, Class target) {
if (!"".equals(xpath))
return false;
//if (target != Geometry.class || target != GeometryAttribute.class)
// return false;
return (object instanceof Feature || object instanceof FeatureType);
}
public Object get(Object object, String xpath, Class target) {
if (object instanceof Feature)
return ((Feature) object).getDefaultGeometryProperty();
if (object instanceof FeatureType) {
FeatureType ft = (FeatureType) object;
GeometryDescriptor gd = ft.getGeometryDescriptor();
if ( gd == null ) {
//look for any geometry descriptor
for ( PropertyDescriptor pd : ft.getDescriptors() ) {
if ( Geometry.class.isAssignableFrom( pd.getType().getBinding() ) ) {
return pd;
}
}
}
return gd;
}
return null;
}
public void set(Object object, String xpath, Object value, Class target)
throws IllegalAttributeException {
if (object instanceof Feature) {
final Feature f = (Feature) object;
GeometryAttribute geom;
if (value instanceof GeometryAttribute) {
geom = (GeometryAttribute) value;
f.setDefaultGeometryProperty(geom);
} else if (value instanceof Geometry) {
geom = f.getDefaultGeometryProperty();
geom.setValue(value);
} else {
throw new IllegalArgumentException("Argument is not a geometry: " + value);
}
}
if (object instanceof FeatureType) {
throw new IllegalAttributeException(null, "feature type is immutable");
}
}
}
static class FeaturePropertyAccessor implements PropertyAccessor {
/*static {
// TODO: use a wrapper public class for Feature in order to
// support any implementation. Reason being that JXPath works
// over concrete classes and hence we cannot set it up over the
// interface
JXPathIntrospector.registerDynamicClass(FeatureImpl.class,
AttributePropertyHandler.class);
JXPathIntrospector.registerDynamicClass(SimpleFeatureImpl.class,
AttributePropertyHandler.class);
JXPathIntrospector.registerDynamicClass(ComplexAttributeImpl.class,
AttributePropertyHandler.class);
JXPathIntrospector.registerDynamicClass(AttributeImpl.class,
AttributePropertyHandler.class);
JXPathIntrospector.registerDynamicClass(GeometryAttributeImpl.class,
AttributePropertyHandler.class);
// JXPathIntrospector.registerDynamicClass(BooleanAttribute.class,
// AttributePropertyHandler.class);
// JXPathIntrospector.registerDynamicClass(NumericAttribute.class,
// AttributePropertyHandler.class);
// JXPathIntrospector.registerDynamicClass(TemporalAttribute.class,
// AttributePropertyHandler.class);
// JXPathIntrospector.registerDynamicClass(TextualAttribute.class,
// AttributePropertyHandler.class);
JXPathIntrospector.registerDynamicClass(AttributeDescriptorImpl.class,
AttributeDescriptorPropertyHandler.class);
JXPathIntrospector.registerDynamicClass(FeatureTypeImpl.class,
AttributeDescriptorPropertyHandler.class);
JXPathIntrospector.registerDynamicClass(UniqueNameFeatureTypeImpl.class,
AttributeDescriptorPropertyHandler.class);
}*/
private NamespaceSupport namespaces;
public FeaturePropertyAccessor() {
namespaces = new NamespaceSupport();
}
public FeaturePropertyAccessor(NamespaceSupport namespaces) {
this.namespaces = namespaces;
}
public boolean canHandle(Object object, String xpath, Class target) {
return object instanceof Attribute || object instanceof AttributeType
|| object instanceof AttributeDescriptor;
}
public Object get(Object object, String xpath, Class target) {
JXPathContext context = JXPathContext.newContext(object);
Enumeration declaredPrefixes = namespaces.getDeclaredPrefixes();
while (declaredPrefixes.hasMoreElements()) {
String prefix = (String) declaredPrefixes.nextElement();
String uri = namespaces.getURI(prefix);
context.registerNamespace(prefix, uri);
}
Iterator it = context.iteratePointers(xpath);
List results = new ArrayList<Object>();
while(it.hasNext()) {
Pointer pointer = (Pointer) it.next();
if (pointer instanceof AttributeNodePointer) {
results.add (((AttributeNodePointer) pointer).getImmediateAttribute());
} else {
results.add(pointer.getValue());
}
}
if (results.size()==0) {
throw new IllegalArgumentException("x-path gives no results.");
} else if (results.size()==1) {
return results.get(0);
} else {
return results;
}
}
public void set(Object object, String xpath, Object value, Class target)
throws IllegalAttributeException {
if (object instanceof FeatureType) {
throw new IllegalAttributeException(null, "feature type is immutable");
}
JXPathContext context = JXPathContext.newContext(object);
Enumeration declaredPrefixes = namespaces.getDeclaredPrefixes();
while (declaredPrefixes.hasMoreElements()) {
String prefix = (String) declaredPrefixes.nextElement();
String uri = namespaces.getURI(prefix);
context.registerNamespace(prefix, uri);
}
context.setValue(xpath, value);
assert value == context.getValue(xpath);
}
}
}