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