mapnik/plugins/input/ogr/ogr_datasource.cpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2007 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
 *
 *****************************************************************************/
// $Id$

#include "ogr_datasource.hpp"
#include "ogr_featureset.hpp"

using std::clog;
using std::endl;

using mapnik::datasource;
using mapnik::parameters;

DATASOURCE_PLUGIN(ogr_datasource)

using mapnik::Envelope;
using mapnik::coord2d;
using mapnik::query;
using mapnik::featureset_ptr;
using mapnik::layer_descriptor;
using mapnik::attribute_descriptor;
using mapnik::datasource_exception;


ogr_datasource::ogr_datasource(parameters const& params)
   : datasource(params),
     extent_(),
     desc_(*params.get<std::string>("type"),"utf-8")
{
   OGRRegisterAll();

   boost::optional<std::string> file = params.get<std::string>("file");
   if (!file) throw datasource_exception("missing <file> paramater");

   boost::optional<std::string> layer = params.get<std::string>("layer");
   if (!layer) throw datasource_exception("missing <layer> paramater");

   dataset_ = OGRSFDriverRegistrar::Open ((*file).c_str(), FALSE);
   if (!dataset_) throw datasource_exception(CPLGetLastErrorMsg());

#if 0
   double x0 = -std::numeric_limits<float>::max(),
           y0 = -std::numeric_limits<float>::max(),
           x1 = std::numeric_limits<float>::max(),
           y1 = std::numeric_limits<float>::max();

   for (int i = 0; i < dataset_->GetLayerCount (); i++)
   {
       OGRLayer* layer = dataset_->GetLayer (i);
       
       layer->GetExtent (&envelope);
       
       x0 = std::min (envelope.MinX, x0);
       y0 = std::min (envelope.MinY, y0);
       x1 = std::max (envelope.MaxX, x1);
       y1 = std::max (envelope.MaxY, y1);
   }
#endif

   layer_ = dataset_->GetLayerByName ((*layer).c_str());
   if (! layer_) throw datasource_exception("cannot find <layer> in dataset");
   
   OGREnvelope envelope;
   layer_->GetExtent (&envelope);
   extent_.init (envelope.MinX, envelope.MinY, envelope.MaxX, envelope.MaxY);

   OGRFeatureDefn* def = layer_->GetLayerDefn ();
   if (def != 0)
   {
       for (int i = 0; i < def->GetFieldCount (); i++)
       {
           OGRFieldDefn* fld = def->GetFieldDefn (i);

           std_string fld_name = fld->GetNameRef ();
           OGRFieldType type_oid = fld->GetType ();

           switch (type_oid)
           {
           case OFTInteger:
           // case OFTIntegerList:
               desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Integer));
               break;

           case OFTReal:
           //case OFTRealList:
               desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Double));
               break;
                   
           case OFTString:
           //case OFTStringList:
               desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::String));
               break;
              
           case OFTBinary:
               desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Object));
               break;
               
           case OFTDate:
           case OFTTime:
           case OFTDateTime: // unhandled !
#ifdef MAPNIK_DEBUG
               clog << "unhandled type_oid="<<type_oid<<endl;
#endif
               break;

           case OFTWideString:
           case OFTWideStringList: // deprecated !
#ifdef MAPNIK_DEBUG
               clog << "deprecated type_oid="<<type_oid<<endl;
#endif
               break;

           default: // unknown
#ifdef MAPNIK_DEBUG
               clog << "unknown type_oid="<<type_oid<<endl;
#endif
               break;
           }
       }
   }
}

ogr_datasource::~ogr_datasource()
{
    OGRDataSource::DestroyDataSource (dataset_);
}

std::string const ogr_datasource::name_="ogr";

std::string ogr_datasource::name()
{
   return name_;
}

int ogr_datasource::type() const
{
   return datasource::Raster;
}

Envelope<double> ogr_datasource::envelope() const
{
   return extent_;
}

layer_descriptor ogr_datasource::get_descriptor() const
{
   return desc_;
}

featureset_ptr ogr_datasource::features(query const& q) const
{
   if (dataset_ && layer_)
   {
        mapnik::Envelope<double> const& query_extent = q.get_bbox();

        OGRLinearRing ring;
	    ring.addPoint (query_extent.minx(), query_extent.miny());
	    ring.addPoint (query_extent.maxx(), query_extent.miny());
	    ring.addPoint (query_extent.maxx(), query_extent.maxy());
	    ring.addPoint (query_extent.minx(), query_extent.maxy());

        OGRPolygon* boxPoly = new OGRPolygon();
	    boxPoly->addRing (&ring);
	    boxPoly->closeRings();

#if 0
        std::ostringstream s;
            
        s << "select ";
        std::set<std::string> const& props=q.property_names();
        std::set<std::string>::const_iterator pos=props.begin();
        std::set<std::string>::const_iterator end=props.end();
        while (pos != end)
        {
           s <<",\""<<*pos<<"\"";
           ++pos;
        }	 
        s << " from " << table_<<" where "<<geometryColumn_<<" && setSRID('BOX3D(";
        s << std::setprecision(16);
        s << box.minx() << " " << box.miny() << ",";
        s << box.maxx() << " " << box.maxy() << ")'::box3d,"<<srid_<<")";

        OGRLayer * dataset_->ExecuteSQL(const char *pszSQLCommand,
                                      OGRGeometry *poSpatialFilter,
                                      const char *pszDialect );
#endif

        return featureset_ptr(new ogr_featureset(*dataset_, *layer_, boxPoly, false));
   }
   return featureset_ptr();
}

featureset_ptr ogr_datasource::features_at_point(coord2d const& pt) const
{
   return featureset_ptr();
}