overpass_turbo_trails_to_gpx

overpass_turbo_trails_to_gpx.js

// export NODE_PATH=/usr/local/lib/node_modules

// https://overpass-turbo.eu/
// [out:json];
// relation(area:3600014296)[route=bicycle]({{bbox}});
// out body;
// >;
// out skel qt;

var fs = require('fs');
var obj = JSON.parse(fs.readFileSync('export.json', 'utf8'));

var nodes = {};
obj.elements.filter(e => e.type === 'node').forEach(e => {
    // id, lat, lon
    nodes[e.id] = {lat: e.lat, lon: e.lon};
});

var ways = {};
obj.elements.filter(e => e.type === 'way').forEach(e => {
    // id, nodes
    ways[e.id] = e.nodes;
});

function s(s) {
    return s ? (s + "").replace("/", ",") : "";
}

obj.elements.filter(e => e.type === 'relation' && e.tags.state !== 'proposed').forEach(e => {
    var builder = require('xmlbuilder');

    var gpx = builder.create("gpx")
            .att('xlns', 'http://www.topografix.com/GPX/1/1')
            .att('version', '1.1')
            .att('xmlns:xsi', 'http://www.w3.org/2001/XMLSchema-instance')
            .att('xsi:schemaLocation', 'http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd');

    var trk = gpx.ele('trk');

    e.members.filter(m => m.type === 'way').forEach(m => {
        trkseg = trk.ele('trkseg');

        ways[m.ref].forEach(n => {
            var node = nodes[n];
            trkseg.ele('trkpt', {lat: node.lat, lon: node.lon});
        });
    });

    fs.writeFileSync("ct/" + (e.id + " | " + s(e.tags.colour) + " | " + s(e.tags.ref) + " | " + s(e.tags.name)).replace("  ", " ") + ".gpx", gpx.end({pretty: true}));
});