app/assets/javascripts/index_modules/directions/engines/graphhopper.js

   1 //= require polyline_decoder
   2
   3 (function () {
   4   function GraphHopperEngine(modeId, vehicleType, profile) {
   5     const GH_INSTR_MAP = {
   6       "-3": "sharp-left",
   7       "-2": "left",
   8       "-1": "slight-left",
   9       "0": "straight",
  10       "1": "slight-right",
  11       "2": "right",
  12       "3": "sharp-right",
  13       "4": "destination", // finish reached
  14       "5": "destination", // via reached
  15       "6": "roundabout",
  16       "-7": "fork-left",
  17       "7": "fork-right",
  18       "-98": "u-turn-left", // unknown direction u-turn
  19       "-8": "u-turn-left", // left u-turn
  20       "8": "u-turn-right" // right u-turn
  21     };
  22
  23     function _processDirections(path) {
  24       const line = OSM.decodePolyline(path.points, { precision: 5 });
  25
  26       const steps = path.instructions.map(instr => [
  27         GH_INSTR_MAP[instr.sign],
  28         instr.text,
  29         instr.distance,
  30         line.slice(instr.interval[0], instr.interval[1] + 1)
  31       ]);
  32
  33       steps.at(-1)[0] = "destination";
  34
  35       return {
  36         line,
  37         steps,
  38         distance: path.distance,
  39         time: path.time / 1000,
  40         ascend: path.ascend,
  41         descend: path.descend
  42       };
  43     }
  44
  45     return {
  46       mode: modeId,
  47       provider: "graphhopper",
  48       draggable: false,
  49
  50       getRoute: function (points, signal) {
  51         // GraphHopper Directions API documentation https://docs.graphhopper.com
  52         const query = new URLSearchParams({
  53           profile: vehicleType,
  54           locale: OSM.i18n.locale,
  55           key: "7cb4eb19-e0f4-40a3-a5e0-f2c039366f32",
  56           elevation: false,
  57           instructions: true
  58         });
  59         const demoQuery = new URLSearchParams({ profile });
  60
  61         for (const { lat, lng } of points) {
  62           query.append("point", [lat, lng]);
  63           demoQuery.append("point", [lat, lng]);
  64         }
  65
  66         const meta = {
  67           credit: "GraphHopper",
  68           creditlink: "https://www.graphhopper.com/",
  69           demolink: "https://graphhopper.com/maps/?" + demoQuery
  70         };
  71
  72         return fetch(OSM.GRAPHHOPPER_URL + "?" + query, { signal })
  73           .then(response => response.json())
  74           .then(({ paths }) => {
  75             if (!paths || paths.length === 0) throw new Error();
  76
  77             return { ..._processDirections(paths[0]), ...meta };
  78           });
  79       }
  80     };
  81   }
  82
  83   OSM.directionsEngines.add(new GraphHopperEngine("car", "car", "car"), true);
  84   OSM.directionsEngines.add(new GraphHopperEngine("bicycle", "bike", "bike"), true);
  85   OSM.directionsEngines.add(new GraphHopperEngine("foot", "foot", "foot"), true);
  86 }());