/***************************************************************************** * * This file is part of Mapnik (c++ mapping toolkit) * * Copyright (C) 2011 Artem Pavlenko * * This library 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 2.1 of the License, or (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * *****************************************************************************/ #ifndef OGR_LAYER_PTR_HPP #define OGR_LAYER_PTR_HPP // mapnik #include <mapnik/debug.hpp> // stl #include <stdexcept> // ogr #include <ogrsf_frmts.h> class ogr_layer_ptr { public: ogr_layer_ptr() : datasource_(NULL), layer_(NULL), owns_layer_(false), is_valid_(false) { } ~ogr_layer_ptr() { free_layer(); } void free_layer() { if (owns_layer_ && layer_ != NULL && datasource_ != NULL) { datasource_->ReleaseResultSet(layer_); } datasource_ = NULL; layer_ = NULL; layer_name_ = ""; owns_layer_ = false; is_valid_ = false; } void layer_by_name(OGRDataSource* const datasource, std::string const& layer_name) { free_layer(); datasource_ = datasource; OGRLayer* ogr_layer = datasource_->GetLayerByName(layer_name.c_str()); if (ogr_layer) { layer_name_ = layer_name; layer_ = ogr_layer; is_valid_ = true; MAPNIK_LOG_DEBUG(ogr) << "ogr_layer_ptr: layer_from_name layer=" << layer_name_; } #ifdef MAPNIK_LOG debug_print_last_error(); #endif } void layer_by_index(OGRDataSource* const datasource, int layer_index) { free_layer(); datasource_ = datasource; OGRLayer* ogr_layer = datasource_->GetLayer(layer_index); if (ogr_layer) { OGRFeatureDefn* def = ogr_layer->GetLayerDefn(); if (def != 0) { layer_ = ogr_layer; layer_name_ = def->GetName(); is_valid_ = true; MAPNIK_LOG_DEBUG(ogr) << "ogr_layer_ptr: layer_from_index layer=" << layer_name_; } } #ifdef MAPNIK_LOG debug_print_last_error(); #endif } void layer_by_sql(OGRDataSource* const datasource, std::string const& layer_sql) { free_layer(); datasource_ = datasource; owns_layer_ = true; // TODO - actually filter fields! // http://trac.osgeo.org/gdal/wiki/rfc29_desired_fields // http://trac.osgeo.org/gdal/wiki/rfc28_sqlfunc OGRGeometry* spatial_filter = NULL; const char* sql_dialect = NULL; OGRLayer* ogr_layer = datasource_->ExecuteSQL(layer_sql.c_str(), spatial_filter, sql_dialect); if (ogr_layer) { OGRFeatureDefn* def = ogr_layer->GetLayerDefn(); if (def != 0) { layer_ = ogr_layer; layer_name_ = def->GetName(); is_valid_ = true; MAPNIK_LOG_DEBUG(ogr) << "ogr_layer_ptr: layer_from_sql layer=" << layer_name_; } } #ifdef MAPNIK_LOG debug_print_last_error(); #endif } std::string const& layer_name() const { return layer_name_; } OGRLayer* layer() const { return layer_; } bool is_valid() const { return is_valid_; } private: #ifdef MAPNIK_LOG void debug_print_last_error() { if (! is_valid_) { const std::string err = CPLGetLastErrorMsg(); if (err.size() == 0) { MAPNIK_LOG_DEBUG(ogr) << "ogr_layer_ptr: Error getting layer"; } else { MAPNIK_LOG_DEBUG(ogr) << "ogr_layer_ptr: " << err; } } } #endif OGRDataSource* datasource_; OGRLayer* layer_; std::string layer_name_; bool owns_layer_; bool is_valid_; }; #endif // OGR_LAYER_PTR_HPP