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/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2012 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
*
*****************************************************************************/
#include "geojson_datasource.hpp"
#include "geojson_featureset.hpp"
#include <fstream>
#include <iostream>
#include <algorithm>
// boost
#include <boost/variant.hpp>
#include <boost/make_shared.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/spirit/include/support_multi_pass.hpp>
#include <boost/foreach.hpp>
#include <boost/geometry/geometries/box.hpp>
#include <boost/geometry/geometries/geometries.hpp>
#include <boost/geometry.hpp>
#include <boost/geometry/extensions/index/rtree/rtree.hpp>
// mapnik
#include <mapnik/box2d.hpp>
#include <mapnik/debug.hpp>
#include <mapnik/proj_transform.hpp>
#include <mapnik/projection.hpp>
#include <mapnik/util/geometry_to_ds_type.hpp>
#include <mapnik/json/feature_collection_parser.hpp>
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(geojson_datasource)
geojson_datasource::geojson_datasource(parameters const& params, bool bind)
: datasource(params),
type_(datasource::Vector),
desc_(*params_.get<std::string>("type"),
*params_.get<std::string>("encoding","utf-8")),
file_(*params_.get<std::string>("file","")),
extent_(),
tr_(new mapnik::transcoder(*params_.get<std::string>("encoding","utf-8"))),
features_(),
tree_(16,1)
{
if (file_.empty()) throw mapnik::datasource_exception("GeoJSON Plugin: missing <file> parameter");
if (bind)
{
this->bind();
}
}
struct attr_value_converter : public boost::static_visitor<mapnik::eAttributeType>
{
mapnik::eAttributeType operator() (int /*val*/) const
{
return mapnik::Integer;
}
mapnik::eAttributeType operator() (double /*val*/) const
{
return mapnik::Double;
}
mapnik::eAttributeType operator() (float /*val*/) const
{
return mapnik::Double;
}
mapnik::eAttributeType operator() (bool /*val*/) const
{
return mapnik::Boolean;
}
mapnik::eAttributeType operator() (std::string const& /*val*/) const
{
return mapnik::String;
}
mapnik::eAttributeType operator() (UnicodeString const& /*val*/) const
{
return mapnik::String;
}
mapnik::eAttributeType operator() (mapnik::value_null const& /*val*/) const
{
return mapnik::String;
}
};
void geojson_datasource::bind() const
{
if (is_bound_) return;
typedef std::istreambuf_iterator<char> base_iterator_type;
std::ifstream is(file_.c_str());
boost::spirit::multi_pass<base_iterator_type> begin =
boost::spirit::make_default_multi_pass(base_iterator_type(is));
boost::spirit::multi_pass<base_iterator_type> end =
boost::spirit::make_default_multi_pass(base_iterator_type());
mapnik::context_ptr ctx = boost::make_shared<mapnik::context_type>();
mapnik::json::feature_collection_parser<boost::spirit::multi_pass<base_iterator_type> > p(ctx,*tr_);
bool result = p.parse(begin,end, features_);
if (!result)
{
throw mapnik::datasource_exception("geojson_datasource: Failed parse GeoJSON file '" + file_ + "'");
}
bool first = true;
std::size_t count=0;
BOOST_FOREACH (mapnik::feature_ptr f, features_)
{
mapnik::box2d<double> const& box = f->envelope();
if (first)
{
extent_ = box;
first = false;
mapnik::feature_kv_iterator itr = f->begin();
mapnik::feature_kv_iterator end = f->end();
for ( ;itr!=end; ++itr)
{
desc_.add_descriptor(mapnik::attribute_descriptor(boost::get<0>(*itr),
boost::apply_visitor(attr_value_converter(),boost::get<1>(*itr).base())));
}
}
else
{
extent_.expand_to_include(box);
}
tree_.insert(box_type(point_type(box.minx(),box.miny()),point_type(box.maxx(),box.maxy())), count++);
}
is_bound_ = true;
}
geojson_datasource::~geojson_datasource() { }
const char * geojson_datasource::name()
{
return "geojson";
}
boost::optional<mapnik::datasource::geometry_t> geojson_datasource::get_geometry_type() const
{
boost::optional<mapnik::datasource::geometry_t> result;
int multi_type = 0;
unsigned num_features = features_.size();
for (unsigned i = 0; i < num_features && i < 5; ++i)
{
mapnik::util::to_ds_type(features_[i]->paths(),result);
if (result)
{
int type = static_cast<int>(*result);
if (multi_type > 0 && multi_type != type)
{
result.reset(mapnik::datasource::Collection);
return result;
}
multi_type = type;
}
}
return result;
}
mapnik::datasource::datasource_t geojson_datasource::type() const
{
return type_;
}
mapnik::box2d<double> geojson_datasource::envelope() const
{
if (!is_bound_) bind();
return extent_;
}
mapnik::layer_descriptor geojson_datasource::get_descriptor() const
{
if (!is_bound_) bind();
return desc_;
}
mapnik::featureset_ptr geojson_datasource::features(mapnik::query const& q) const
{
if (!is_bound_) bind();
// if the query box intersects our world extent then query for features
mapnik::box2d<double> const& b = q.get_bbox();
if (extent_.intersects(b))
{
box_type box(point_type(b.minx(),b.miny()),point_type(b.maxx(),b.maxy()));
index_array_ = tree_.find(box);
return boost::make_shared<geojson_featureset>(features_, index_array_.begin(), index_array_.end());
}
// otherwise return an empty featureset pointer
return mapnik::featureset_ptr();
}
// FIXME
mapnik::featureset_ptr geojson_datasource::features_at_point(mapnik::coord2d const& pt, double tol) const
{
if (!is_bound_) bind();
throw mapnik::datasource_exception("GeoJSON Plugin: features_at_point is not supported yet");
return mapnik::featureset_ptr();
}
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