Add a Field class and implement some loading of it in Document.

[online-glom:gwt-glom.git] / src / main / java / org / glom / web / server / database / DetailsDBAccess.java

/*
 * Copyright (C) 2011 Openismus GmbH
 *
 * This file is part of GWT-Glom.
 *
 * GWT-Glom 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, either version 3 of the License, or (at your
 * option) any later version.
 *
 * GWT-Glom 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.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with GWT-Glom.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.glom.web.server.database;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import org.glom.libglom.LayoutFieldVector;
import org.glom.libglom.Value;
import org.glom.web.server.Log;
import org.glom.web.server.SqlUtils;
import org.glom.web.server.Utils;
import org.glom.web.shared.DataItem;
import org.glom.web.shared.TypedDataItem;
import org.glom.web.shared.libglom.Document;
import org.glom.web.shared.libglom.Field;

import com.mchange.v2.c3p0.ComboPooledDataSource;

/**
 *
 */
public class DetailsDBAccess extends DBAccess {

        public DetailsDBAccess(final Document document, final String documentID, final ComboPooledDataSource cpds,
                        final String tableName) {
                super(document, documentID, cpds, tableName);
                this.tableName = tableName;
        }

        public DataItem[] getData(final TypedDataItem primaryKeyValue) {

                final LayoutFieldVector fieldsToGet = getFieldsToShowForSQLQuery(document.get_data_layout_groups("details",
                                tableName));

                if (fieldsToGet == null || fieldsToGet.size() <= 0) {
                        Log.warn(documentID, tableName, "Didn't find any fields to show. Returning null.");
                        return null;
                }

                final Field primaryKey = getPrimaryKeyField(tableName);

                if (primaryKey == null) {
                        Log.error(documentID, tableName, "Couldn't find primary key in table. Returning null.");
                        return null;
                }

                ArrayList<DataItem[]> rowsList = new ArrayList<DataItem[]>();
                Connection conn = null;
                Statement st = null;
                ResultSet rs = null;
                Value gdaPrimaryKeyValue = null;
                try {
                        // Setup the JDBC driver and get the query.
                        conn = cpds.getConnection();
                        st = conn.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);

                        gdaPrimaryKeyValue = Utils.getGlomTypeGdaValueForTypedDataItem(documentID, tableName,
                                        primaryKey.get_glom_type(), primaryKeyValue);

                        // Only create the query if we've created a Gda Value from the TypedDataItem.
                        if (gdaPrimaryKeyValue != null) {

                                final String query = SqlUtils.build_sql_select_with_key(conn, tableName, fieldsToGet, primaryKey,
                                                gdaPrimaryKeyValue);

                                rs = st.executeQuery(query);

                                // get the results from the ResultSet
                                // using 2 as a length parameter so we can log a warning if appropriate
                                rowsList = convertResultSetToDTO(2, fieldsToGet, rs);
                        }

                } catch (final SQLException e) {
                        Log.error(documentID, tableName, "Error executing database query.", e);
                        // TODO: somehow notify user of problem
                        return null;
                } finally {
                        // cleanup everything that has been used
                        try {
                                if (rs != null)
                                        rs.close();
                                if (st != null)
                                        st.close();
                                if (conn != null)
                                        conn.close();
                        } catch (final Exception e) {
                                Log.error(documentID, tableName,
                                                "Error closing database resources. Subsequent database queries may not work.", e);
                        }
                }

                if (rowsList.size() == 0) {
                        Log.error(documentID, tableName, "The query returned an empty ResultSet. Returning null.");
                        return null;
                } else if (rowsList.size() > 1 && !gdaPrimaryKeyValue.is_null()) {
                        // Only log a warning if the result size is greater than 1 and the gdaPrimaryKeyValue is not null. When
                        // gdaPrimaryKeyValue.is_null() is true, the default query for the details view is being executed so we
                        // expect a result set that is larger than one.
                        Log.warn(documentID, tableName,
                                        "The query did not return the expected unique result. Returning the first result in the set.");
                }

                return rowsList.get(0);
        }
}