Application: gvSIG desktop

package org.gvsig.fmap.dal.impl.expressionevaluator;

import java.util.List;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.ExpressionEvaluatorLocator;

import org.gvsig.expressionevaluator.ExpressionEvaluatorManager;

import org.gvsig.expressionevaluator.ExpressionRuntimeException;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

import org.gvsig.expressionevaluator.spi.AbstractSymbolTable;

import org.gvsig.fmap.dal.DALLocator;

import org.gvsig.fmap.dal.DataManager;

import org.gvsig.fmap.dal.DataStore;

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

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

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

/**

 *

 * @author jjdelcerro

 */

@SuppressWarnings("UseSpecificCatch")

public class DALSymbolTable extends AbstractSymbolTable {

    public static final String FUNCTION_FEATURES = "FEATURES";

    public static class FeaturesFunction extends AbstractFunction {

        public FeaturesFunction() {

            super(

                    "Data access",

                    FUNCTION_FEATURES,

                    Range.between(1, 3),

                    "Return a list of the features selecteds with filter in the store.",

                    FUNCTION_FEATURES + "({{store_name}}, filter, order)",

                    new String[]{

                        "store - data store name to be used",

                        "where - Optional. String value with a filter expression",

                        "order - Optional. String value with the order. must be a string with the names of separate fields with commas"

                    },

                    "LIST"

            );

        }

        @Override

        public Object call(Interpreter interpreter, Object[] args) throws Exception {

            String storeName = getStr(args, 0);

            String where = null;

            String order = null;

            switch (args.length) {

                case 2:

                    where = getStr(args, 1);

                    break;

                case 3:

                    where = getStr(args, 1);

                    order = getStr(args, 2);

                    break;

            }

            try {

                DataStore store = this.getStore(storeName);

                if (store == null || !(store instanceof FeatureStore)) {

                    throw new ExpressionRuntimeException("Cant locate the store '" + storeName + "' in function '" + FUNCTION_FEATURES + "'.");

                }

                if (!(store instanceof FeatureStore)) {

                    throw new ExpressionRuntimeException("The store'" + storeName + "' is not valid for function '" + FUNCTION_FEATURES + "', a FeatureStore is required.");

                }

                FeatureStore featureStore = (FeatureStore) store;

                List<Feature> features;

                if (where == null && order == null) {

                    features = featureStore.getFeatures();

                } else {

                    FeatureQuery query = featureStore.createFeatureQuery();

                    if (where != null) {

                        query.addFilter(where);

                    }

                    if (order != null) {

                        query.getOrder().add(order);

                    }

                    query.retrievesAllAttributes();

                    features = featureStore.getFeatures(query);

                }

                return features;

            } catch (ExpressionRuntimeException ex) {

                throw ex;

            } catch (Exception ex) {

                throw new ExpressionRuntimeException("Problems calling '" + FUNCTION_FEATURES + "' function", ex);

            }

        }

        protected DataStore getStore(String storeName) {

            DataManager dataManager = DALLocator.getDataManager();

            DataStore store = dataManager.getStoresRepository().get(storeName);

            return store;

        }

    }

    @SuppressWarnings("OverridableMethodCallInConstructor")

    public DALSymbolTable() {

        super(DataManager.DAL_SYMBOL_TABLE);

        this.addFunction(new FeaturesFunction());

    }

    public static void selfRegister() {

        ExpressionEvaluatorManager manager = ExpressionEvaluatorLocator.getManager();

        manager.registerSymbolTable(new DALSymbolTableFactory());

    }

}