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

   1 (function () {
   2   function GraphHopperEngine(modeId, vehicleType, profile) {
   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
  31       steps.at(-1)[0] = "destination";
  32
  33       return {
  34         line,
  35         steps,
  36         distance: path.distance,
  37         time: path.time / 1000,
  38         ascend: path.ascend,
  39         descend: path.descend
  40       };
  41     }
  42
  43     return {
  44       mode: modeId,
  45       provider: "graphhopper",
  46       draggable: false,
  47
  48       getRoute: function (points, signal) {
  49         // GraphHopper Directions API documentation https://docs.graphhopper.com
  50         const query = new URLSearchParams({
  51           profile: vehicleType,
  52           locale: OSM.i18n.locale,
  53           key: "7cb4eb19-e0f4-40a3-a5e0-f2c039366f32",
  54           elevation: false,
  55           instructions: true
  56         });
  57         const demoQuery = new URLSearchParams({ profile });
  58
  59         for (const { lat, lng } of points) {
  60           query.append("point", [lat, lng]);
  61           demoQuery.append("point", [lat, lng]);
  62         }
  63
  64         const meta = {
  65           credit: "GraphHopper",
  66           creditlink: "https://www.graphhopper.com/",
  67           demolink: "https://graphhopper.com/maps/?" + demoQuery
  68         };
  69
  70         return fetch(OSM.GRAPHHOPPER_URL + "?" + query, { signal })
  71           .then(response => response.json())
  72           .then(({ paths }) => {
  73             if (!paths || paths.length === 0) throw new Error();
  74
  75             return { ..._processDirections(paths[0]), ...meta };
  76           });
  77       }
  78     };
  79   }
  80
  81   OSM.Directions.addEngine(new GraphHopperEngine("car", "car", "car"), true);
  82   OSM.Directions.addEngine(new GraphHopperEngine("bicycle", "bike", "bike"), true);
  83   OSM.Directions.addEngine(new GraphHopperEngine("foot", "foot", "foot"), true);
  84 }());