Application: gvSIG desktop

package org.gvsig.fmap.dal.feature.impl.dynobjectutils.relations;

import org.gvsig.fmap.dal.DALLocator;

import org.gvsig.fmap.dal.DataManager;

import org.gvsig.fmap.dal.DataStoreParameters;

import org.gvsig.fmap.dal.feature.Feature;

import org.gvsig.fmap.dal.feature.FeatureAttributeDescriptor;

import org.gvsig.fmap.dal.feature.FacadeOfAFeature;

import org.gvsig.fmap.dal.feature.FeatureQuery;

import org.gvsig.fmap.dal.feature.FeatureSet;

import org.gvsig.fmap.dal.feature.FeatureStore;

import org.gvsig.tools.dispose.DisposableIterator;

import org.gvsig.tools.dispose.DisposeUtils;

import org.gvsig.tools.dynobject.AbstractDynMethod;

import org.gvsig.tools.dynobject.DynField_v2;

import org.gvsig.tools.dynobject.DynObject;

import org.gvsig.tools.dynobject.exception.DynMethodException;

public class DALLink_getRelatedFeature extends AbstractDynMethod {

    private static final String DAL_code = "DAL.code";

    private static final String DAL_foreingTable = "DAL.foreingTable";

    private static final String DAL_foreingCode = "DAL.foreingCode";

    public DALLink_getRelatedFeature() {

        super("DAL.getRelatedFeature","Retrieve the element of the other side of the relation.");

    }

    public Object invoke(DynObject self, Object[] args) throws DynMethodException {

        if (!(self instanceof FacadeOfAFeature)) {

            return null;

        }

        DynField_v2 field = (DynField_v2) args[0];

        String codeName = (String) field.getTags().get(DAL_code);

        String foreignTableName = (String) field.getTags().get(DAL_foreingTable);

        String foreignCodeName = (String) field.getTags().get(DAL_foreingCode);

        Feature feature = ((FacadeOfAFeature) self).getFeature();

        return getRelatedFeature(feature, codeName, foreignTableName, foreignCodeName);

    }

    private DynObject getRelatedFeature(Feature feature, String attrName, String otherStoreName, String otherAttrName) throws ComputeRelatedFeatureException {

        Object fkValue = "<unknow>";

        FeatureSet set = null;

        DisposableIterator it = null;

        try {

            FeatureStore store = feature.getStore();

            DataManager manager = DALLocator.getDataManager();

            FeatureAttributeDescriptor attrdesc = feature.getType().getAttributeDescriptor(attrName);

            DataStoreParameters foreignStoreParmeters = store.getExplorer().get(otherStoreName);

            FeatureStore foreignStore = (FeatureStore) manager.openStore(store.getProviderName(), foreignStoreParmeters);

            FeatureQuery query = foreignStore.createFeatureQuery();

            fkValue = feature.get(attrName);

            if (attrdesc.getDataType().isNumeric()) {

                fkValue = fkValue.toString();

            } else {

                fkValue = "'" + fkValue.toString().replace("'", "''") + "'";

            }

            String where = otherAttrName + " = " + fkValue;

            query.addFilter(manager.createExpresion(where));

            set = foreignStore.getFeatureSet(query);

            if( set.getSize()!= 1 ) {

                throw new ComputeRelatedFeatureException(otherStoreName, otherAttrName, fkValue.toString());

            }

            it = set.fastIterator();

            Feature otherFeature = (Feature) it.next();

            return otherFeature.getAsDynObject();

        } catch (Exception ex) {

            throw new ComputeRelatedFeatureException(otherStoreName, otherAttrName, fkValue.toString(), ex);

        } finally {

            DisposeUtils.disposeQuietly(it);

            DisposeUtils.disposeQuietly(set);

        }

    }

    private static class ComputeRelatedFeatureException extends DynMethodException {

        private final static String MESSAGE_FORMAT = "Can't retrieve relation items from %(storename)s for attribute %(attrname)s with value %(attrvalue)s.";

        private final static String MESSAGE_KEY = "_OneToManyMethodException";

        private static final long serialVersionUID = -3248317756866564508L;

        public ComputeRelatedFeatureException(String storename, String attrname, String attrvalue) {

            super(MESSAGE_FORMAT, MESSAGE_KEY, serialVersionUID);

            setValue("storename", storename);

            setValue("attrname", attrname);

            setValue("attrvalue", attrvalue);

        }

        public ComputeRelatedFeatureException(String storename, String attrname, String attrvalue, Throwable cause) {

            this(storename,attrname, attrvalue);

            this.initCause(cause);

        }

    }

}