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(function (instr) {
  25         const lineseg = line
  26           .slice(instr.interval[0], instr.interval[1] + 1);
  27         return [
  28           lineseg[0],
  29           GH_INSTR_MAP[instr.sign],
  30           instr.text,
  31           instr.distance,
  32           lineseg
  33         ];
  34       });
  35       steps.at(-1)[1] = "destination";
  36
  37       return {
  38         line: line,
  39         steps: steps,
  40         distance: path.distance,
  41         time: path.time / 1000,
  42         ascend: path.ascend,
  43         descend: path.descend
  44       };
  45     }
  46
  47     return {
  48       mode: modeId,
  49       provider: "graphhopper",
  50       creditline: "<a href=\"https://www.graphhopper.com/\" target=\"_blank\">GraphHopper</a>",
  51       draggable: false,
  52
  53       getRoute: function (points, signal) {
  54         // GraphHopper Directions API documentation
  55         // https://graphhopper.com/api/1/docs/routing/
  56         const query = new URLSearchParams({
  57           vehicle: vehicleType,
  58           locale: OSM.i18n.locale,
  59           key: "LijBPDQGfu7Iiq80w3HzwB4RUDJbMbhs6BU0dEnn",
  60           elevation: false,
  61           instructions: true,
  62           turn_costs: vehicleType === "car"
  63         });
  64         points.forEach(p => query.append("point", p.lat + "," + p.lng));
  65         return fetch(OSM.GRAPHHOPPER_URL + "?" + query, { signal })
  66           .then(response => response.json())
  67           .then(({ paths }) => {
  68             if (!paths || paths.length === 0) throw new Error();
  69             return _processDirections(paths[0]);
  70           });
  71       }
  72     };
  73   }
  74
  75   OSM.Directions.addEngine(new GraphHopperEngine("car", "car"), true);
  76   OSM.Directions.addEngine(new GraphHopperEngine("bicycle", "bike"), true);
  77   OSM.Directions.addEngine(new GraphHopperEngine("foot", "foot"), true);
  78 }());