app/assets/javascripts/index/directions/graphhopper.js

   1 (function () {
   2   function GraphHopperEngine(modeId, vehicleType) {
   3     const GH_INSTR_MAP = {
   4       "-3": "sharp-left",
   5       "-2": "left",
   6       "-1": "slight-left",
   7       "0": "straight",
   8       "1": "slight-right",
   9       "2": "right",
  10       "3": "sharp-right",
  11       "4": "destination", // finish reached
  12       "5": "destination", // via reached
  13       "6": "roundabout",
  14       "-7": "fork-left",
  15       "7": "fork-right",
  16       "-98": "u-turn-left", // unknown direction u-turn
  17       "-8": "u-turn-left", // left u-turn
  18       "8": "u-turn-right" // right u-turn
  19     };
  20
  21     function _processDirections(path) {
  22       const line = L.PolylineUtil.decode(path.points);
  23
  24       const steps = path.instructions.map(instr => [
  25         GH_INSTR_MAP[instr.sign],
  26         instr.text,
  27         instr.distance,
  28         line.slice(instr.interval[0], instr.interval[1] + 1)
  29       ]);
  30       steps.at(-1)[0] = "destination";
  31
  32       return {
  33         line,
  34         steps,
  35         distance: path.distance,
  36         time: path.time / 1000,
  37         ascend: path.ascend,
  38         descend: path.descend,
  39         credit: "GraphHopper",
  40         creditlink: "https://www.graphhopper.com/"
  41       };
  42     }
  43
  44     return {
  45       mode: modeId,
  46       provider: "graphhopper",
  47       draggable: false,
  48
  49       getRoute: function (points, signal) {
  50         // GraphHopper Directions API documentation
  51         // https://graphhopper.com/api/1/docs/routing/
  52         const query = new URLSearchParams({
  53           vehicle: vehicleType,
  54           locale: OSM.i18n.locale,
  55           key: "LijBPDQGfu7Iiq80w3HzwB4RUDJbMbhs6BU0dEnn",
  56           elevation: false,
  57           instructions: true,
  58           turn_costs: vehicleType === "car"
  59         });
  60         points.forEach(p => query.append("point", p.lat + "," + p.lng));
  61         return fetch(OSM.GRAPHHOPPER_URL + "?" + query, { signal })
  62           .then(response => response.json())
  63           .then(({ paths }) => {
  64             if (!paths || paths.length === 0) throw new Error();
  65             return _processDirections(paths[0]);
  66           });
  67       }
  68     };
  69   }
  70
  71   OSM.Directions.addEngine(new GraphHopperEngine("car", "car"), true);
  72   OSM.Directions.addEngine(new GraphHopperEngine("bicycle", "bike"), true);
  73   OSM.Directions.addEngine(new GraphHopperEngine("foot", "foot"), true);
  74 }());