Error trying to implement "geo" postgrex extention type

Question

I'm following this tutorial which adds a postgrex extension into the config.exs with the extensions field. However that is now a deprecated way to add a postgrex extension, we should now use the type field instead of the extensions field. I'm following the code on the geo library github page, to add the extension:

config.exs

Postgrex.Types.define(MyApp.PostgresTypes,
  [Geo.PostGIS.Extension] ++ Ecto.Adapters.Postgres.extensions(),
  json: Poison)

use Mix.Config

config :api, Api.Repo,
  types: MyApp.PostgresTypes,
  adapter: Ecto.Adapters.Postgres,
  database: "api_repo",
  username: "postgres",
  password: "postgres",
  hostname: "localhost",
  web_port: String.to_integer(System.get_env("PORT") || "4000"),
  timeout: 60_000,
  pool_timeout: 60_000

config :api, ecto_repos: [Api.Repo]

But I'm getting this error:

bash-3.2$ mix ecto.migrate
** (Mix.Config.LoadError) could not load config config/config.exs
    ** (UndefinedFunctionError) function Ecto.Adapters.Postgres.extensions/0 is undefined (module Ecto.Adapt
ers.Postgres is not available)
    Ecto.Adapters.Postgres.extensions()
    (stdlib) erl_eval.erl:670: :erl_eval.do_apply/6
    (stdlib) erl_eval.erl:470: :erl_eval.expr/5
    (stdlib) erl_eval.erl:878: :erl_eval.expr_list/6
    (stdlib) erl_eval.erl:404: :erl_eval.expr/5
    (stdlib) erl_eval.erl:122: :erl_eval.exprs/5

I have seen online this is sometimes due to a version of postgrex however that is a very old version and I'm using {:postgrex, "~> 0.13.2"},. What am I missing?

@a_horse_with_no_name Ah, no. I just installed Geo as a dep: `[{:geo, "~> 1.4"}]` in my deps. I will download PostGis — BeniaminoBaggins, May 28 '17 at 07:31
Which version of Ecto are you using? (see in mix.lock for the exact version) — Dogbert, May 28 '17 at 08:13

score 7 · Accepted Answer · answered May 28 '17 at 08:23

The line defining the custom Postgrex types needs to go in a .ex file that is compiled with your app (anything in lib/ and web/), not in a config file. Configuration files do not have access to the application's dependencies' functions.

So, if you move this code to e.g. lib/my_app/postgres_types.ex:

Postgrex.Types.define(MyApp.PostgresTypes,
  [Geo.PostGIS.Extension] ++ Ecto.Adapters.Postgres.extensions(),
  json: Poison)

Your shouldn't get the undefined function error anymore and everything should work assuming you've followed the rest of the instructions in the geo package correctly.

Error trying to implement "geo" postgrex extention type

1 Answers1