activerecord-postgis-adapter: Encode WKT

Question

Using activerecord-postgis-adapter, how can I parse / encode wkt in results from database query?

I've got a simple model of Places:

class CreatePlaces < ActiveRecord::Migration[5.1]
 def change

  create_table :places do |t|
    t.string :name
    t.st_point :coords, :geographic => true

    t.timestamps
  end

  change_table :places do |t|
    t.index :coords, using: :gist
  end

 end
end

I get all places in following way:

class PlacesController < ApplicationController

 def index
   @places = Place.all

   render json: @places.to_json
 end

end

But my JSON in response contains WKT:

[
  {
      "id": 1,
      "name": "test name 1",
      "coords": "POINT (50.324192 19.037805)",
      "created_at": "2017-09-07T20:29:19.203Z",
      "updated_at": "2017-09-07T20:29:19.203Z"
  }
]

I can map @places and encode coords like this:

class PlacesController < ApplicationController

  def index
    @places = Place.all

    @places.map { |k,v| k.coords = RGeo::GeoJSON.encode(k.coords, json_parser: :json) }

    render json: @places.to_json
  end

end

And then I get what I wanted - encoded/parsed coords in GeoJSON form:

[
  {
      "id": 1,
      "name": "test name 1",
      "coords": {
          "type": "Point",
          "coordinates": [
              50.324192,
              19.037805
          ]
      },
      "created_at": "2017-09-07T20:29:19.203Z",
      "updated_at": "2017-09-07T20:29:19.203Z"
  }
]

Is it right way to encode POINT?

Answer 1

Add this code to one of your initializers:

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

See https://stackoverflow.com/a/6221804