Hi guys!

In this moment I am working in a large umbrella application composed for around 4 applications each one has their own models that are using this implementation for Poison.Encoder

defimpl Poison.Encoder, for: Any do
    def encode(%{__struct__: App.Models.Task} = struct, options) do
    struct =
        if struct.geom do
            {lon, lat} =  struct.geom.coordinates
            %{struct | lon: lon, lat: lat}
        else
            struct
        end
        encode_model(struct, options)
    end

    def encode(%{__struct__: _} = struct, options) do
        encode_model(struct, options)
    end

    def encode({lon, lat}, options) when is_float(lon) and is_float(lat) do
        %{lon: lon, lat: lat}
        |> sanitize_map()
        |> Poison.Encoder.Map.encode(options)
    end

    defp encode_model(model, options) do
        model
        |> Map.from_struct()
        |> sanitize_map()
        |> Poison.Encoder.Map.encode(options)
    end

    defp sanitize_map(map) do
        map
        |> Enum.filter(
            fn({_, %Ecto.Association.NotLoaded{}}) -> false
            ({:__meta__, _}) -> false
            ({:__struct__, _}) -> false
            ({_, _}) -> true
           end)
    |> Map.new()
    end
end

My model looks like:

# App.Models.Task
@derive {Poison.Encoder, only: [
  :address,
  :address_extra,
  :geom,
  :country,
  :dep_state,
  :city,
  :zip_code,
  :lat,
  :lon
]}
schema "tasks" do
  field(:address, :string)
  field(:address_extra, :string)
  field(:geom, Geo.Geometry)
  field(:country, :string)
  field(:dep_state, :string)
  field(:city, :string)
  field(:zip_code, :string)
  field(:lat, :float, virtual: true)
  field(:lon, :float, virtual: true)
  
  belongs_to(:service, App.Models.Service)
  timestamps()
end

This obviously doesn’t work once I want to compile my releases (using distillery) since I’m overriding the existing encoder implementations. So, in order to fix the issue I will need to implement Poison.Encoder using @derive in my models.

So the thing is, I know preloading the relationships is the way to go, but, what if I don’t want to preload all the relationships of my models? There are another way to go? If this is the only way, at least can I skip preloading relationships?

Thank you so much in advance for your time.