Allow properties to be added to Geo types

[jerel]

Is there a PostGIS (or other) limitation that would prevent us from adding properties to the Geo structs?

For example it would be very nice to be able to do the following:

%Geo.Point{coordinates: {1, 1}, properties: %{time: "12:01"}}
|> Geo.JSON.encode()

[bryanjos]

There is no limitation that would prevent that. It would just be ignored unless used by something like the Geo.JSON module. I think adding properties is fine.

If another request for adding a GeoJSON specific item comes up, I'm leaning towards making something that follows the spec exactly that wraps around the Geo structs.

[larsbutler]

@jerel

Is there a PostGIS (or other) limitation that would prevent us from adding properties to the Geo structs?

The GeoJSON RFC states that "FeatureCollection and Geometry objects, respectively, MUST NOT contain a "geometry" or "properties" member." This came up in a discussion I had with one of the RFC authors.

It seems that the general theme here is a lack of support for metadata. Your cases is pretty custom, but there are some cases where metadata is vital to retaining information when converting between formats (GeoJSON to/from EWKT/EWKB, for example). Relevant issues:

• Support for EWKB? geomet/geomet#28
• srid in GeoJSON output #76

I would really like to see some official guidance for how to include metadata/extensions in the GeoJSON schema. I'll have to go and do a bit of research.

[niahoo]

Hi,

That's exactly what the Feature geojson type is for. It has two members, geometry and properties.

FeatureCollection has only one member (besides type) : features :: [Feature].

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "Hanoi",
        "month_notes": [2, 2, 3, 4, 3, 2, 2, 2, 3, 4, 5, 3],
        "location": "Hanoi, Vietnam",
        "country": "vietnam"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          105.8341598,
          21.0277644
        ]
      }
    },
    ...

Any plans to implement it ?

[bryanjos]

I've been thinking about this a lot and I think instead of trying to shoehorn geojson features into the geometry types, maybe it would be cleaner to create struct(s) around geojson itself. Maybe that's a better direction to move towards

[niahoo]

But this is not stoehorning, the Feature type exists for this sole purpose : have geometry and properties in one entity ...

[bryanjos]

Looking at the spec and thinking on it a bit, I think adding properties to the types should be fine.

[bryanjos]

Fixed in 4647ed3