How can i resolve this MarkerCluster checkin/ checkout error (leaflet salesforce)?

Question

The problem is that when i check out on overlay and after i check in again i receive this error:

Uncaught TypeError: Cannot read property 'x' of undefined throws at dist/leaflet.markercluster.js:1:25696 TypeError: Cannot read property 'x' of undefined at L.DistanceGrid._sqDist (DistanceGrid.js:114)
at L.DistanceGrid.getNearObject (DistanceGrid.js:94) at e._addLayer (MarkerClusterGroup.js:974) at eval (MarkerClusterGroup.js:249)
at e.addLayers (MarkerClusterGroup.js:283) at e.addLayers (layersupport.js:99) at e.onAdd (layersupport.js:517) at e._layerAdd (leaflet.js:5) at e.whenReady (leaflet.js:5) at e.addLayer (leaflet.js:5)

I saw that this function from DistanceGrid(is in leaflet library) which is called when i check in on the overlay 

_sqDist: function (p, p2) {
      var dx = p2.x - p.x,
          dy = p2.y - p.y;
      return dx * dx + dy * dy;
  }

And when i checked in is p is somehow undefined. Im struggling with this error for a long period already. Maybe you have some suggestion

Markers are defined for the groups and they are properly displayed the issue is only with check in check out. Once i check them out the clusters dissapear as they should and once i checked in i receive that error mentioned before instead of showing clusters back on the map

Here is the controller code:

JS controller: 
var map = L.map('map', {zoomControl: true, tap: false, preferCanvas:true})
var group1,group2,group3,group4;
var myRenderer = L.canvas({ padding: 0.5 });
 var markers = L.markerClusterGroup.layerSupport( { 
        chunkedLoading: true,
        renderer: myRenderer,
        iconCreateFunction: function  (cluster) {
        var childCount = cluster.getChildCount();

        var c = ' marker-cluster-';
        if (childCount < 10) {
            c += 'small';
        } 
        else if (childCount < 100) {
            c += 'medium';
        } 
        else {
                c += 'large';
        }

        return new L.DivIcon({ html: '<div><span>' + childCount + '</span> 
</div>', 
                              className: 'marker-cluster' + c, iconSize: 
 new L.Point(40, 40) });
            }
});

 group1 = L.layerGroup(),
       group2 = L.layerGroup(),
      group3 = L.layerGroup(),
       group4 = L.layerGroup(),

    markers.checkIn([group1, group2, group3, group4]);

    var overlayMaps = {
        "g1": group1,
        "g2": group2,
        "g3":group3,
        "g4":group4
    };
    var control = L.control.layers(null, overlayMaps, { collapsed: true });


    control.addTo(map);

    group1.addTo(map); // Adding to map or to AutoMCG are now equivalent.
    group2.addTo(map);
    group3.addTo(map);
    group4.addTo(map);

 markers.addTo(map);

PS: I dont know how to give a workable version since this a salesforce app

Answer 1

It is possible that the chunkedLoading option is not well handled by the Leaflet.markercluster.layerSupport plugin.

I am not sure why you need to "checkout" and "checkin" regularly? Are you rather referring to using the Layers Control to remove / add your overlay?

Otherwise, if you "only" need a solution to use Leaflet.markercluster with the Layers Control, you can give a try to the simpler plugin Leaflet.FeatureGroup.SubGroup, although if chunkedLoading is the reason for the issue, it would probably also be the same with that plugin.