Leaflet.draw generated a geojson which is not valid

[fab-girard]

Hello,
I'm reporting a bug but I'm not sure it's a bug in leaflet.draw or leaflet.

How to reproduce

• Leaflet version I'm using: 1.0.3
• Leaflet Draw version I'm using: 0.4.9
• Scenario:
  . create or update a polygon with leaflet.draw
  . use .toGeoJSON() on the feature created/updated
  => the json hasn't the "type": "Feature" key/value. Geojson is incorrect.

What behaviour I'm expecting and which behaviour I'm seeing

=> geojson should be valid with type key

Minimal example reproducing the issue

I've created jsfiddle to reproduce the problem (geojson is displayed under the map when you create/update the draw).

Thanks,
Fabien

[ddproxy]

So

1. The type: is NOT feature and it should be?
2. They type: IS feature and it should not be?

[fab-girard]

Mmmh strange.
On my app, geojson hasn't "type": "Feature" when I edit a just created draw. Last week I thought jsfiddle demo hadn't neither that part in geojson but it seems it is present when I check today...
I need a couple of days to understand what has changed.

Fab

[fab-girard]

Ok got it...
On my app I use in addition leaflet-pip which uses a function:

function isPoly(l) {
    return l.feature &&
        l.feature.geometry &&
        l.feature.geometry.type &&
        ['Polygon', 'MultiPolygon'].indexOf(l.feature.geometry.type) !== -1;
}

This function doesn't work with a layer (polygon) drawed by leaflet-draw because there is no feature.geometry.type. To fix it I've added feature.geometry.type = 'Feature' to layer created by leaflet-draw in my code. But when I add this attribute manualy, it seems to influence on update command of draw (and geojson hasn't all required attribute as explained previously).

The original issue is in fact: no feature.geometry.type on layer object generated by leaflet-draw. I don't know if it is a defect from leaflet-draw or it's a correct behavior. Maybe isPoly function in leaflet-pip could be more permissive. I found the last update of this function and it seems it has been simplified for support only Leaflet 1.0:
mapbox/leaflet-pip@a66bb22#diff-168726dbe96b3ce427e7fedce31bb0bcL5

Have you an idea of the change maybe between features/geojson management in leaflet <1.0 and >=1.0 ?

Fab

[ddproxy]

Hey @fab-girard,

A Feature geometry does seem to have a geometry.type when using toGeoJson,

{
   "type":"Feature",
   "properties":{

   },
   "geometry":{
      "type":"Polygon",
      "coordinates":[
         [
            [
               -2.5488281250000004,
               45.49094569262732
            ],
            [
               -2.5488281250000004,
               44.43377984606825
            ],
            [
               -1.2744140625000002,
               44.43377984606825
            ],
            [
               -1.3183593750000002,
               45.49094569262732
            ],
            [
               -2.5488281250000004,
               45.49094569262732
            ]
         ]
      ]
   }
}

I'm curious if you are losing the type somewhere between toGeoJSON and your isPoly call? Since I don't have more information I can't really tell?

[fab-girard]

To begin: thanks for your support.
As I've tried to explain I was loosing the type: Feature in geoJson because of a line I've added after a draw is created.
I've updated the jsfiddle to show you the problem: http://jsfiddle.net/kveke1s5/15/ (line 38 has been added : this line allows to return true in isPoly function)
I thought this line could help me to use leaflet-pip which uses (and declare) the isPoly function. If you run the demo you will see with this added line, the geoJson is not valid (type: Feature is missing).
I think now it was not the good way to fix my problem to use leaflet-draw and leaflet-pip plugins together.

Now I'm thinking the isPoly function could be more permissive. Maybe it could be:

function isPoly(l) {
    if (L.MultiPolygon) {
        return l instanceof L.MultiPolygon || l instanceof L.Polygon;
    }
    if (l instanceof L.Polygon) return true; // THIS LINE IS NECESSARY TO WORK WITH leaflet-draw
    // Leaflet >= 1.0
    return l.feature.geometry && l.feature.geometry.type &&
         ['Polygon', 'MultiPolygon'].indexOf(l.feature.geometry.type) !== -1;
}

But maybe I'm wrong another time... Maybe the layer created by leaflet-draw is not correct and should return true for l.feature.geometry && l.feature.geometry.type && ['Polygon', 'MultiPolygon'].indexOf(l.feature.geometry.type) !== -1; which is not the case at this moment...
Thanks again.

[ddproxy]

@fab-girard Try looking at the feature group you are adding to instead...

  div.appendChild(document.createTextNode('Created: ' + JSON.stringify(featureGroup.toGeoJSON())));
  document.getElementById('geojson').appendChild(div);

Rather than referencing the event, this featureGroup returns a FeatureCollection with a different structure.