Finding a route with WrldNavigation and displaying directions

Using the WrldNavigation widget to find and display the directions for a route between two locations. To display the route on the map see this example using the WrldRouteView Widget
<!DOCTYPE HTML>
<html>
  <head>
    <script src="https://unpkg.com/wrld.js@1.x.x"></script>
    <link href="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.0.1/leaflet.css" rel="stylesheet" />
    
    <link href="https://cdn-webgl.wrld3d.com/wrldjs/addons/resources/v1/latest/css/wrld.css" rel="stylesheet"/>
    <script src="https://cdn-webgl.wrld3d.com/wrldjs/addons/navigation/v1/latest/navigation.js"></script>

  </head>
  
  <body>
  <div style="position: relative">
    <div id="map" style="height: 500px">
      <div id="navigation-widget-container" style="position: absolute; left: 0px; right: 0px; top: 0px; bottom: 0px; overflow: hidden;"></div>
    </div>
    <div style="position: absolute; top: 0; right: 0; display: flex; flex-direction: column; z-index: 20;">
      <button onclick="openNavWidget()">Open</button>
      <button onclick="closeNavWidget()">Close</button>
      <button onclick="resetNavWidget()">Reset</button>
      <select id="locations">
        <option value="" disabled selected >Locations</option>
        <option value="west_ward_works">West Ward Works</option>
        <option value="abertay">Abertay</option>
        <option value="westport_house">Westport House</option>
      </select>
      <button onclick="setStartLocation()">Set Start Location</button>
      <button onclick="setEndLocation()">Set End Location</button>
      <button onclick="clearLocations()">Clear Locations</button>
      <button onclick="findRoute()">Find Route</button>
      <button onclick="clearDirections()">Clear Directions</button>
    </div>
    <script>
      var apiKey = "your_api_key_here";

      var map = Wrld.map("map", apiKey, {
        center: [56.461762, -2.975963],
        zoom: 16
      });
      
      var locations = {
        abertay: WrldNavigation.buildLocation("Abertay", 56.463008, -2.974135),
        westport_house: WrldNavigation.buildLocation("Westport House", 56.4600344, -2.9783117, "westport_house", 2),
        west_ward_works: WrldNavigation.buildLocation("West Ward Works", 56.4612316, -2.9831228)
      }

      var startLocation = {};
      var endLocation = {};

      var navigation = new WrldNavigation("navigation-widget-container", map, apiKey);
      navigation.on("swapjourneylocations", (event) => { console.log(event);onNavWidgetSwapJourneyLocations(); });

      function clearDirections() {
        navigation.clearDirections();
      }

      function clearLocations() {
        startLocation = {};
        endLocation = {};
        navigation.clearLocations();
      }

      function findRoute() {
        navigation.findRoute(startLocation, endLocation, findRouteCallback);
      }

      function findRouteCallback(result) {
        if (result.route) {
          navigation.buildDirectionsForRoute(result.route, buildDirectionsCallback);
        }
      }

      function buildDirectionsCallback(result) {
        if (result.directions) {
          navigation.setDirections(result.directions);
          navigation.setRouteDuration(result.route.routeDuration);
        }
      }

      function setStartLocation() {
        var locationId = document.getElementById("locations").value;
        startLocation = locations[locationId] || {};
        navigation.setStartLocation(startLocation);
      }

      function setEndLocation() {
        var locationId = document.getElementById("locations").value;
        endLocation = locations[locationId] || {};
        navigation.setEndLocation(endLocation);
      }
      
      function onNavWidgetSwapJourneyLocations() {
        const tmp = startLocation;
        startLocation = endLocation;
        endLocation = tmp;
      }

      function openNavWidget() {
        navigation.openControl();
      }

      function closeNavWidget() {
        navigation.closeControl();
      }

      function resetNavWidget() {
        navigation.resetControl();
      }
      
    </script>
  </div>
  </body>
</html>