FeatureNearestValueSelectionStrategyImpl.java

/* (c) 2014 - 2016 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2014 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.wms.dimension.impl;

import java.io.IOException;
import java.util.List;

import org.geoserver.catalog.AttributeTypeInfo;
import org.geoserver.catalog.DimensionInfo;
import org.geoserver.catalog.FeatureTypeInfo;
import org.geoserver.catalog.ResourceInfo;
import org.geoserver.wms.dimension.AbstractFeatureAttributeVisitorSelectionStrategy;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.feature.visitor.CalcResult;
import org.geotools.feature.visitor.FeatureCalc;
import org.geotools.feature.visitor.NearestVisitor;
import org.geotools.util.Converters;
import org.opengis.filter.FilterFactory2;

/**
 * Default implementation for selecting the default values for dimensions of 
 * feature (vector) resources using the nearest-domain-value-to-the-reference-value
 * strategy.
 *  
 * @author Ilkka Rinne / Spatineo Inc for the Finnish Meteorological Institute
 *
 */

public class FeatureNearestValueSelectionStrategyImpl extends
        AbstractFeatureAttributeVisitorSelectionStrategy {

    private Object toMatch;
    private String fixedCapabilitiesValue;
    private FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2();
    
    /**
     * Default constructor.
     */
    public FeatureNearestValueSelectionStrategyImpl(Object toMatch){
        this(toMatch,null);
    }
        
    public FeatureNearestValueSelectionStrategyImpl(Object toMatch, String capabilitiesValue) {
        this.toMatch = toMatch;
        this.fixedCapabilitiesValue = capabilitiesValue;
    }

    @Override
    public Object getDefaultValue(ResourceInfo resource, String dimensionName,
            DimensionInfo dimension, Class clz) {        
        String attrName = dimension.getAttribute();
        Class<?> attrType = String.class;
        if (resource instanceof FeatureTypeInfo){
            List<AttributeTypeInfo> attrTypes;
            try {
                attrTypes = ((FeatureTypeInfo)resource).attributes();
                for (AttributeTypeInfo attr:attrTypes){
                    if (attr.getName().equals(attrName)){
                        attrType = attr.getBinding();
                        break;
                    }
                }
            } catch (IOException e) {
            }                       
        }

        final FeatureCalc nearest = new NearestVisitor(ff.property(dimension.getAttribute()),
                this.toMatch);
        
        CalcResult res = getCalculatedResult((FeatureTypeInfo) resource, dimension, nearest);
        if (res.equals(CalcResult.NULL_RESULT)) {
            return null;
        } else {
            return Converters.convert(res.getValue(),clz);
        }
    }

    @Override
    public String getCapabilitiesRepresentation(ResourceInfo resource, String dimensionName, DimensionInfo dimensionInfo) {
        if (fixedCapabilitiesValue != null){
            return this.fixedCapabilitiesValue;
        } else {
            return super.getCapabilitiesRepresentation(resource, dimensionName, dimensionInfo);
        }
    }

  
}