Question

A rails service I am currently working on requires that points are returned as a GeoJSON object within our json response. We are using rgeo and the mysql2spatial adapter to represent these points in our application and I would like to use the rgeo-geojson gem to handle the encoding if possible (we already use it to decode geojson on post).

I am currently overwriting as_json with the following code to achieve this:

   def as_json(params)
     l = {:lat_lng => ::RGeo::GeoJSON.encode(lat_lng)}
     self.attributes.merge(l).as_json
   end

However this is not optimal as the root (eg object: {}) is missing. Is there a function to easily include it? (a lot of our models have a lat_lng associated, so I’d rather not hard code it).

Any tips for a ruby/rails beginner would be greatly appreciated

Answer 1

For posterity, I fixed this in the “rgeo-activerecord” gem, version 0.3.4, after getting several reports on it. By default it renders spatial columns in WKT. To switch it to GeoJSON, set this:

RGeo::ActiveRecord::GeometryMixin.set_json_generator(:geojson)

The answer by NielsV will work sometimes but not every time. Specifically, it will work for geographic factories (i.e. geometry columns in PostGIS) but not for GEOS-backed factories.