mapnik/test/unit/datasource/topojson.cpp
2024-07-22 10:20:47 +01:00

163 lines
6.9 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2024 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 "catch.hpp"
#include "ds_test_util.hpp"
#include <mapnik/util/fs.hpp>
#include <mapnik/util/file_io.hpp>
#include <mapnik/json/topology.hpp>
#include <mapnik/json/topojson_grammar_x3.hpp>
#include <mapnik/json/topojson_utils.hpp>
#define HEREDOC(...) #__VA_ARGS__
namespace {
bool parse_topology_string(std::string const& buffer, mapnik::topojson::topology& topo);
bool parse_topology(std::string const& filename, mapnik::topojson::topology& topo)
{
mapnik::util::file file(filename);
std::string buffer;
buffer.resize(file.size());
std::fread(&buffer[0], buffer.size(), 1, file.get());
if (!file)
return false;
return parse_topology_string(buffer, topo);
}
bool parse_topology_string(std::string const& buffer)
{
mapnik::topojson::topology topo;
return parse_topology_string(buffer, topo);
}
bool parse_topology_string(std::string const& buffer, mapnik::topojson::topology& topo)
{
using space_type = boost::spirit::x3::standard::space_type;
char const* itr = buffer.c_str();
char const* end = itr + buffer.length();
try
{
boost::spirit::x3::phrase_parse(itr, end, mapnik::json::grammar::topology, space_type(), topo);
}
catch (boost::spirit::x3::expectation_failure<char const*> const& ex)
{
std::cerr << "failed to parse TopoJSON..." << std::endl;
std::cerr << ex.what() << std::endl;
std::cerr << "Expected: " << ex.which();
std::cerr << "\nGot: \"";
auto ctx = ex.where();
std::streamsize len = 0;
// stop before NUL terminator or after 200 bytes, whichever comes first
for (; ctx[len] && len < 200; ++len)
;
// extend to UTF-8 character boundary or 210 bytes, whichever comes first
for (; len < 210 && ((unsigned char)ctx[len] & 0xC0) == 0x80; ++len)
;
std::cerr.write(ctx, len);
std::cerr << (ctx[len] ? "..." : "") << '"' << std::endl;
return false;
}
return (itr == end);
}
} // namespace
TEST_CASE("TopoJSON")
{
SECTION("Minimal Topology")
{
// + A topology must have a member with the name “objects” whose value is another object.
// + A topology must have a member with the name “arcs” whose value is an array of arcs.
CHECK(parse_topology_string(HEREDOC({"type" : "Topology", "objects" : {}, "arcs" : []})));
CHECK(parse_topology_string(HEREDOC({"type" : "Topology", "arcs" : [], "objects" : {}})));
CHECK(parse_topology_string(HEREDOC({"objects" : {}, "type" : "Topology", "arcs" : []})));
CHECK(parse_topology_string(HEREDOC({"objects" : {}, "arcs" : [], "type" : "Topology"})));
CHECK(parse_topology_string(HEREDOC({"arcs" : [], "type" : "Topology", "objects" : {}})));
CHECK(parse_topology_string(HEREDOC({"arcs" : [], "objects" : {}, "type" : "Topology"})));
}
SECTION("geometry parsing")
{
mapnik::value_integer feature_id = 0;
mapnik::context_ptr ctx = std::make_shared<mapnik::context_type>();
mapnik::transcoder tr("utf8");
for (auto const& path : mapnik::util::list_directory("test/data/topojson/"))
{
mapnik::topojson::topology topo;
REQUIRE(parse_topology(path, topo));
for (auto const& geom : topo.geometries)
{
mapnik::box2d<double> bbox =
mapnik::util::apply_visitor(mapnik::topojson::bounding_box_visitor(topo), geom);
CHECK(bbox.valid());
mapnik::topojson::feature_generator<mapnik::context_ptr> visitor(ctx, tr, topo, feature_id++);
mapnik::feature_ptr feature = mapnik::util::apply_visitor(visitor, geom);
CHECK(feature);
CHECK(feature->envelope() == bbox);
}
}
}
SECTION("TopoJSON properties are properly expressed")
{
std::string filename("./test/data/topojson/escaped.topojson");
mapnik::context_ptr ctx = std::make_shared<mapnik::context_type>();
mapnik::transcoder tr("utf8");
mapnik::topojson::topology topo;
REQUIRE(parse_topology(filename, topo));
mapnik::value_integer feature_id = 0;
for (auto const& geom : topo.geometries)
{
mapnik::box2d<double> bbox =
mapnik::util::apply_visitor(mapnik::topojson::bounding_box_visitor(topo), geom);
CHECK(bbox.valid());
mapnik::topojson::feature_generator<mapnik::context_ptr> visitor(ctx, tr, topo, feature_id);
mapnik::feature_ptr feature = mapnik::util::apply_visitor(visitor, geom);
CHECK(feature);
CHECK(feature->envelope() == bbox);
std::initializer_list<attr> attrs = {
attr{"name", tr.transcode("Test")},
attr{"NOM_FR", tr.transcode("Québec")},
attr{"boolean", mapnik::value_bool(true)},
attr{"description", tr.transcode("Test: \u005C")},
attr{"double", mapnik::value_double(1.1)},
attr{"int", mapnik::value_integer(1)},
attr{"object",
tr.transcode(
"{\"name\":\"waka\",\"spaces\":\"value with spaces\",\"int\":1,\"double\":1.1,\"boolean\":false"
",\"NOM_FR\":\"Québec\",\"array\":[\"string\",\"value with spaces\",3,1.1,null,true"
",\"Québec\"],\"another_object\":{\"name\":\"nested object\"}}")},
attr{"spaces", tr.transcode("this has spaces")},
attr{"array",
tr.transcode("[\"string\",\"value with spaces\",3,1.1,null,true,"
"\"Québec\",{\"name\":\"object within an array\"},"
"[\"array\",\"within\",\"an\",\"array\"]]")},
attr{"empty_array", tr.transcode("[]")},
attr{"empty_object", tr.transcode("{}")},
};
REQUIRE_ATTRIBUTES(feature, attrs);
}
}
}