Bing Maps v8 - Clear layers removes route polyline from the map view - maps

Question

When I need to clear map layer on directionsUpdated seting new driving route or change route by drag & drop, the function map.layers.clear() removes the route line.
Any ideas?
var map = new Microsoft.Maps.Map(document.getElementById('myMap'), {
credentials: 'Your Bing Maps Key',
center: new Microsoft.Maps.Location(47.606209, -122.332071),
zoom: 12
});
addPushpins();
Microsoft.Maps.loadModule('Microsoft.Maps.Directions', function () {
var directionsManager = new Microsoft.Maps.Directions.DirectionsManager(map);
// Set Route Mode to driving
directionsManager.setRequestOptions({ routeMode: Microsoft.Maps.Directions.RouteMode.driving });
var waypoint1 = new Microsoft.Maps.Directions.Waypoint({ address: 'Redmond', location: new Microsoft.Maps.Location(47.67683029174805, -122.1099624633789) });
var waypoint2 = new Microsoft.Maps.Directions.Waypoint({ address: 'Seattle', location: new Microsoft.Maps.Location(47.59977722167969, -122.33458709716797) });
directionsManager.addWaypoint(waypoint1);
directionsManager.addWaypoint(waypoint2);
// Set the element in which the itinerary will be rendered
directionsManager.setRenderOptions({ itineraryContainer: document.getElementById('printoutPanel') });
directionsManager.calculateDirections();
Microsoft.Maps.Events.addHandler(directionsManager, 'directionsUpdated', onUpdateDirections);
});
function onUpdateDirections() {
map.layers.clear();
addPushpins();
}
function addPushpins() {
// Generate an array of 10 random pushpins within current map bounds
var pushpins = Microsoft.Maps.TestDataGenerator.getPushpins(10, map.getBounds());
var layer = new Microsoft.Maps.Layer();
layer.add(pushpins);
map.layers.insert(layer);
}

Answer 1

This is by design. The route data is rendered using a layer of it's own. If you clear all layers on the map, then the directions will disappear as well. For your data, reuse a layer instead like this:
var map = new Microsoft.Maps.Map(document.getElementById('myMap'), {
credentials: 'Your Bing Maps Key',
center: new Microsoft.Maps.Location(47.606209, -122.332071),
zoom: 12
});
var layer = new Microsoft.Maps.Layer();
map.layers.insert(layer);
addPushpins();
Microsoft.Maps.loadModule('Microsoft.Maps.Directions', function () {
var directionsManager = new Microsoft.Maps.Directions.DirectionsManager(map);
// Set Route Mode to driving
directionsManager.setRequestOptions({ routeMode: Microsoft.Maps.Directions.RouteMode.driving });
var waypoint1 = new Microsoft.Maps.Directions.Waypoint({ address: 'Redmond', location: new Microsoft.Maps.Location(47.67683029174805, -122.1099624633789) });
var waypoint2 = new Microsoft.Maps.Directions.Waypoint({ address: 'Seattle', location: new Microsoft.Maps.Location(47.59977722167969, -122.33458709716797) });
directionsManager.addWaypoint(waypoint1);
directionsManager.addWaypoint(waypoint2);
// Set the element in which the itinerary will be rendered
directionsManager.setRenderOptions({ itineraryContainer: document.getElementById('printoutPanel') });
directionsManager.calculateDirections();
Microsoft.Maps.Events.addHandler(directionsManager, 'directionsUpdated', onUpdateDirections);
});
function onUpdateDirections() {
layer.clear();
addPushpins();
}
function addPushpins() {
// Generate an array of 10 random pushpins within current map bounds
var pushpins = Microsoft.Maps.TestDataGenerator.getPushpins(10, map.getBounds());
layer.add(pushpins);
}