clearLayers() doesn't always work on geojson layergroups

[brianherbert]

I'm having a hard time reproducing an issue I'm having when I clearLayers() on a geojson layer group. I create a layer group like so:

geojson = {some geojson here}
var geojsonLayer = L.geoJson(geojson, {
...
}).addTo(map);

Then later, I want to refresh the layer by removing it's contents and repopulating it:

geojsonLayer.clearLayers();
geojsonLayer.addData(geojson);

However, when clearLayers executes, I'm seeing an error saying that an event doesn't exist.

I changed line 405 https://github.com/Leaflet/Leaflet/blob/master/dist/leaflet-src.js#L405 to check and make sire it exists before attempting to delete it, like so:

if (events[objKey] !== undefined && events[objKey][contextId] !== undefined) {
    delete events[objKey][contextId];
}

This fixes my issue, but I cannot figure out why it's doing this. Any pointers would be great since I don't want to mess with the core library or submit a pull request if I don't know what's wrong.

I created this simple jsfiddle, which works (much to my frustration): http://jsfiddle.net/3Sqvq/5/

[iirvine]

Hey there - sounds like the issue I've been running into with FeatureGroup events in #1495. It's related to the way Leaflet.Events is indexing listeners in the current master - it's not breaking in your jsfiddle because you're pointed at the last release, 0.5.1, not at master.

I've not really dug into the problem too deep yet - though it seems like ensuring your group has a _leaflet_id by calling L.stamp() on it will at least keep events from throwing that error.

describe("FeatureGroup Events Bug", function() {
    it("When a layer is removed from a FeatureGroup, Leaflet.Events throws error", function() {
        var container = document.createElement('div'),
            map = new L.Map(container).setView([0, 0], 0);

        var group = new L.FeatureGroup();
        var marker = L.marker([0,0]);

        group.addLayer(marker);
        map.addLayer(group);

        expect(function(){
            group.clearLayers();
        }).not.toThrow();
    });
    it("Doesn't throw when a group has been stamped", function() {
        var container = document.createElement('div'),
            map = new L.Map(container).setView([0,0], 0);

        var group = new L.FeatureGroup();
        var marker = L.marker([0,0]);

        L.stamp(group)

        group.addLayer(marker);
        map.addLayer(group);

        expect(function(){group.clearLayers();}).not.toThrow();
    });
});

[danzel]

Thanks guys, will take a look at this and #1495 soon.

[danzel]

@brianherbert Check out #1514 for a fix.

[danzel]

I think this should be closed, fixed AFAIK.

[MacWeber]

It is still not working for me.
I'm coming from this issue #1416

[MacWeber]

I realize I was not on HEAD. layer.clearLayers(); is working fine.