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#include <mbgl/style/sources/geojson_source.hpp>
#include <mbgl/style/source_observer.hpp>
#include <mbgl/style/parser.hpp>
#include <mbgl/tile/geojson_tile.hpp>
#include <mbgl/storage/file_source.hpp>
#include <mbgl/platform/log.hpp>
#include <mapbox/geojsonvt.hpp>
#include <mapbox/geojsonvt/convert.hpp>
#include <rapidjson/error/en.h>
#include <sstream>
namespace mbgl {
namespace style {
std::unique_ptr<mapbox::geojsonvt::GeoJSONVT> parseGeoJSON(const JSValue& value) {
using namespace mapbox::geojsonvt;
Options options;
options.buffer = util::EXTENT / util::tileSize * 128;
options.extent = util::EXTENT;
try {
return std::make_unique<GeoJSONVT>(Convert::convert(value, 0), options);
} catch (const std::exception& ex) {
Log::Error(Event::ParseStyle, "Failed to parse GeoJSON data: %s", ex.what());
// Create an empty GeoJSON VT object to make sure we're not infinitely waiting for
// tiles to load.
return std::make_unique<GeoJSONVT>(std::vector<ProjectedFeature>{}, options);
}
}
std::unique_ptr<GeoJSONSource> GeoJSONSource::parse(const std::string& id,
const JSValue& value) {
auto tileset = std::make_unique<Tileset>();
std::unique_ptr<mapbox::geojsonvt::GeoJSONVT> geojsonvt;
std::string url;
// We should probably split this up to have URLs in the url property, and actual data
// in the data property. Until then, we're going to detect the content based on the
// object type.
if (!value.HasMember("data")) {
Log::Error(Event::ParseStyle, "GeoJSON source must have a data value");
return nullptr;
}
const JSValue& dataVal = value["data"];
if (dataVal.IsString()) {
// We need to load an external GeoJSON file
url = { dataVal.GetString(), dataVal.GetStringLength() };
} else if (dataVal.IsObject()) {
// We need to parse dataVal as a GeoJSON object
geojsonvt = parseGeoJSON(dataVal);
tileset->maxZoom = geojsonvt->options.maxZoom;
} else {
Log::Error(Event::ParseStyle, "GeoJSON data must be a URL or an object");
return nullptr;
}
return std::make_unique<GeoJSONSource>(id, url, std::move(tileset), std::move(geojsonvt));
}
GeoJSONSource::GeoJSONSource(std::string id_,
std::string url_,
std::unique_ptr<Tileset>&& tileset_,
std::unique_ptr<mapbox::geojsonvt::GeoJSONVT>&& geojsonvt_)
: Source(SourceType::GeoJSON, std::move(id_), std::move(url_), util::tileSize, std::move(tileset_)),
geojsonvt(std::move(geojsonvt_)) {
}
GeoJSONSource::~GeoJSONSource() = default;
void GeoJSONSource::load(FileSource& fileSource) {
if (url.empty()) {
// If the URL is empty, the GeoJSON was specified inline in the stylesheet.
loaded = true;
return;
}
if (req) {
return;
}
req = fileSource.request(Resource::source(url), [this](Response res) {
if (res.error) {
observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
} else if (res.notModified) {
return;
} else if (res.noContent) {
observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error("unexpectedly empty GeoJSON")));
} else {
std::unique_ptr<Tileset> newTileset = std::make_unique<Tileset>();
rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> d;
d.Parse<0>(res.data->c_str());
if (d.HasParseError()) {
std::stringstream message;
message << d.GetErrorOffset() << " - " << rapidjson::GetParseError_En(d.GetParseError());
observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(message.str())));
return;
}
geojsonvt = style::parseGeoJSON(d);
newTileset->maxZoom = geojsonvt->options.maxZoom;
invalidateTiles();
tileset = std::move(newTileset);
loaded = true;
observer->onSourceLoaded(*this);
}
});
}
std::unique_ptr<Tile> GeoJSONSource::createTile(const OverscaledTileID& tileID,
const UpdateParameters& parameters) {
return std::make_unique<GeoJSONTile>(tileID, id, parameters, geojsonvt.get());
}
} // namespace style
} // namespace mbgl
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