AGOL export to geojson, holes not represented as expected

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12-09-2020 09:33 AM
Kirk_d
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New Contributor

I am downloading geojson from a government agency that uses a hosted AGOL instance.  The geojson does not appear to come back in the expected format for any polygons with holes (as shown in https://tools.ietf.org/html/rfc7946#appendix-A )

"A.3. Polygons

   Coordinates of a Polygon are an array of linear ring (see
   Section 3.1.6) coordinate arrays.  The first element in the array
   represents the exterior ring.  ...

Instead, the holes are returned as additional rings with reverse winding order.  Is this the expected geojson format to be returned?  Is it a configuration on their server (or hosted service) to specify how holes are represented? 

 

Here is an example using the AGOL viewer (notice the holes)

https://data-nifc.opendata.arcgis.com/datasets/wildfire-perimeters/data?geometry=-125.090%2C39.654%2...

 

Here is a link to get the geojson returned

https://services3.arcgis.com/T4QMspbfLg3qTGWY/arcgis/rest/services/Public_Wildfire_Perimeters_View/F...

Showing that geojson in QGIS, the holes are seen as "filled in".  Same happens with FME.

Any suggestions?  

Kirk

 

 

 

1 Reply
Kirk_d
by
New Contributor

One other addon to this, the geojson is often very slow with large payload.  Is there any documentation regarding how to parse or deserialize if using pbf as the requested output from the service?

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