After entering draw_point mode with no features, getAll() returns a Point with no coordinates

[amagee]

mapbox-gl-js version: 0.44.2 mapbox-gl-draw version: 1.0.7

Steps to Trigger Behavior

Do something like this:

map.addControl(draw);
draw.set({type: 'FeatureCollection', features: []});
draw.changeMode('draw_point');
console.log(draw.getAll());

jsbin: https://jsbin.com/hecipexiju/1/edit?html,output

Expected Behavior

I would have expected draw.getAll() to return an empty FeatureCollection.

Actual Behavior

I get a FeatureCollection with one feature, which is a Point with an empty array as coordinates, which is invalid GeoJSON. I have to manually filter such points out of the object before passing them downstream, otherwise calculations fail.

[allthesignals]

I see this same behavior with draw_polygon:

It actually explicitly adds null to the coordinates there, which is invalid in mapbox-gl.

Happy to take a look at this unless there's a good reason this should be happening. It is unfortunate because it causes some issues downstream.

[bryik]

Just ran into this.

1. Click the polygon tool (try it in the docs example)
2. draw.getAll() will return an invalid polygon:

{
  "type": "FeatureCollection",
  "features": [
    {
      "id": "3e67c3496932bf89b27b1ce74d604c61",
      "type": "Feature",
      "properties": {},
      "geometry": {
        "coordinates": [
          [
            [
              -91.85288565063648,
              42.7185207838487
            ],
            [
              -91.85288565063648,
              42.7185207838487
            ]
          ]
        ],
        "type": "Polygon"
      }
    }
  ]
}

Errors (identified by GeoJSONLint):

• Line 10: a LinearRing of coordinates needs to have four or more positions
• Line 8: Polygons and MultiPolygons should follow the right-hand rule

A similar thing happens with the Point and LineString tools. I imagine mapbox-gl-draw is populating some kind of internal state with partial Features as soon as a tool is clicked. OP's expected behavior is also what I expected (for draw.getAll() to return an empty FeatureCollection).

[nerdynucleon]

I came up with a workaround:

• checking the draw_mode and then unshifting the first element:
• seems like the partially drawn object is always in the front of the list

const allDrawn = draw.getAll();
const features = allDrawn.features;
if (draw.getMode() === 'draw_polygon') {
    features.shift();
}

EDIT: nevermind. the partially drawn object isn't always at the front...

maybe this will work for some people

const prevMode  = draw.getMode()
draw.changeMode('simple_select');
const allDrawn = draw.getAll();
const features = allDrawn.features;
draw.changeMode(prevMode);

[foundryspatial-duncan]

I was just dealing with this; if you run draw.getAll() when a drawing is "incomplete" (polygon not closed or not started), you'll get some extra invalid features (like a polygon with too few coordinates).

It looks like those features get cleaned out of the FeatureCollection if you switch the mode to simple_select before running .getAll().

Good thinking, @nerdynucleon ! You saved me having to manually filter out invalid features from the FeatureCollection :relieved: