topic Re: Merge Polygons in JavaScript API 4.14 in ArcGIS JavaScript Maps SDK Questions

Merge Polygons in JavaScript API 4.14

MikeV — Tue, 04 Feb 2020 02:08:57 GMT

I have several polygons that I'd like not to overlap on the map at the points that they merge at. If I have separate latitude/longitude coordinate sets for all the polygons, how can I accomplish this? In the image below, I want the two circles filled in but not overlapping.

Re: Merge Polygons in JavaScript API 4.14

LeoLiu1 — Tue, 04 Feb 2020 05:57:31 GMT

Do you want an union?

geometryEngine | ArcGIS API for JavaScript 4.14

Re: Merge Polygons in JavaScript API 4.14

MikeV — Tue, 04 Feb 2020 22:24:11 GMT

I'm trying to use geometryEngine.union() with no success. I have several polygons defined like this where paths is an array of lat/long coordinates:

var polygon = { type: "polygon", rings: paths };

I then push each polygon into an array like this:

polygons.push(polygon);

At that point I use

var joinedPolygons = geometryEngine.union(polygons);

The API then throws an error that 'd is undefined'. What am I doing wrong?

Re: Merge Polygons in JavaScript API 4.14

LeoLiu1 — Tue, 04 Feb 2020 23:57:18 GMT

Can you try this:

make sure spatialReference is set for each polygon json, for example:.

var polygon = { type: "polygon", rings: paths, "spatialReference": {"wkid": 4326} };

And then make sure array's type is polygon:

polygons.push(new Polygon(polygon));

If the above doesn't work, can you please share more pieces of codes with a screen shot of the error from your browser's console?

Re: Merge Polygons in JavaScript API 4.14

MikeV — Wed, 05 Feb 2020 02:31:48 GMT

Thanks, geometryEngine.union() works with your advice. The explicit cast to a Polygon before pushing it into my array is what was missing in my code.