Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2020 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.expressionevaluator.impl.function.dataaccess;

import java.util.Arrays;

import java.util.List;

import org.apache.commons.lang3.Range;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.expressionevaluator.ExpressionRuntimeException;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.impl.DALFunctions;

import org.gvsig.fmap.dal.DataManager;

import static org.gvsig.fmap.dal.DataManager.FUNCTION_FOREING_VALUE;

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

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

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

import org.gvsig.tools.util.UnmodifiableBasicList;

import org.gvsig.tools.util.UnmodifiableBasicListAdapter;

import org.gvsig.tools.util.UnmodifiableBasicListArrayAdapter;

public class ForeingValueFunction extends AbstractFeatureFunction {

  public ForeingValueFunction() {

    super(

            DALFunctions.GROUP_DATA_ACCESS, 

            FUNCTION_FOREING_VALUE, 

            Range.is(1), 

            "Return the value of a field throw a relation from other tables.", 

            "FOREING VALUE FROM {{foreing_key_field.field_name}}", 

            new String[]{

              "foreing_key_field - Name of the field in the current table that contains the foreign key of the table that we want to access.",

              "field_name - Name of the field of the related table that we want to access."

            }, 

            "OBJECT",

            true

    );

  }

  @Override

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

    UnmodifiableBasicList<String> fieldNames;

    switch( args.length) {

      case 1:

        Object fields_o = getObject(args, 0);

        if( fields_o == null ) {

          throw new ExpressionRuntimeException("Problems calling '" + DataManager.FUNCTION_FOREING_VALUE + "' function, type of parameter 'null' not supported, use string or list.");

        }

        if (fields_o instanceof String[]) {

          fieldNames = new UnmodifiableBasicListArrayAdapter<>((String[]) fields_o);

        } else if (fields_o instanceof List) {

          fieldNames = new UnmodifiableBasicListAdapter<>((List<String>) fields_o);

        } else if (fields_o instanceof String) {

          fieldNames = new UnmodifiableBasicListAdapter<>(Arrays.asList(((String) fields_o).split("[.]")));

        } else if (fields_o instanceof UnmodifiableBasicList) {

          fieldNames = (UnmodifiableBasicList<String>) fields_o;

        } else {

          throw new ExpressionRuntimeException("Problems calling '" + DataManager.FUNCTION_FOREING_VALUE + "' function, type of parameter '" + fields_o.getClass().getSimpleName() + "' not supported, use string or list.");

        }

        break;

      case 2:

        fieldNames = new UnmodifiableBasicListArrayAdapter<>(

                new String[] {

                  getStr(args, 0),

                  getStr(args, 1)

                }

        );

        break;

      default:

          throw new ExpressionRuntimeException("Problems calling '" + DataManager.FUNCTION_FOREING_VALUE + "' function, type of parameter  not supported, use string or list.");

    }

    Feature feature = this.current_row(interpreter);

    Feature currentFeature = feature;

    try {

      String fieldName;

      Object value;

      value = feature.getExtraValue(StringUtils.join(fieldNames, "."));

      if (value != null) {

        return value;

      }

      for (int i = 0; i < fieldNames.size() - 1; i++) {

        fieldName = fieldNames.get(i);

        value = currentFeature.get(fieldName);

        FeatureAttributeDescriptor attrdesc = currentFeature.getType().getAttributeDescriptor(fieldName);

        if (attrdesc.isForeingKey()) {

            ForeingKey foreingKey = attrdesc.getForeingKey();

            // ContextForeingKey context = foreingKey.createContext();

            currentFeature = foreingKey.getFeature(null, value);

            // DisposeUtils.disposeQuietly(context);

            if (currentFeature == null) {

              return null;

            }

        }

      }

      fieldName = fieldNames.get(fieldNames.size() - 1);

      value = currentFeature.get(fieldName);

      return value;

    } catch (ExpressionRuntimeException ex) {

      throw ex;

    } catch (Exception ex) {

      throw new ExpressionRuntimeException("Problems calling '" + DataManager.FUNCTION_FOREING_VALUE + "' function", ex);

    }

  }

}