gistfile1.txt

defmodule AController do
  def index(conn, _params) do
    user_devices = "foo"

    conn
      |> assign :user_devices, user_devices
      |> render "index.html"
  end
end


Template:
<div class="row-md-12">
    <%= @user_devices %>
</div>


Trace:
[error] #PID<0.923.0> running WoodhouseServer.Endpoint terminated
Server: localhost:4000 (http)
Request: GET /devices
** (exit) an exception was raised:
    ** (FunctionClauseError) no function clause matching in Plug.Conn.put_private/3
        (plug) lib/plug/conn.ex:296: Plug.Conn.put_private("foo", :phoenix_template, "index.html")
        (phoenix) lib/phoenix/controller.ex:623: Phoenix.Controller.do_render/4
        (woodhouse_server) web/controllers/device_controller.ex:14: WoodhouseServer.DeviceController.index/2
        (woodhouse_server) web/controllers/device_controller.ex:1: WoodhouseServer.DeviceController.action/2
        (woodhouse_server) web/controllers/device_controller.ex:1: WoodhouseServer.DeviceController.phoenix_controller_pipeline/2
        (woodhouse_server) lib/phoenix/router.ex:255: WoodhouseServer.Router.dispatch/2
        (woodhouse_server) web/router.ex:1: WoodhouseServer.Router.do_call/2
        (woodhouse_server) lib/woodhouse_server/endpoint.ex:1: WoodhouseServer.Endpoint.phoenix_pipeline/1
        (woodhouse_server) lib/plug/debugger.ex:92: WoodhouseServer.Endpoint."call (overridable 3)"/2
        (woodhouse_server) lib/phoenix/endpoint/render_errors.ex:34: WoodhouseServer.Endpoint.call/2
        (plug) lib/plug/adapters/cowboy/handler.ex:15: Plug.Adapters.Cowboy.Handler.upgrade/4
        (cowboy) src/cowboy_protocol.erl:442: :cowboy_protocol.execute/4

defmodule AController do
  def index(conn, _params) do
    user_devices = "foo"

    conn
    |> assign(:user_devices, user_devices)
    |> render("index.html")
  end
end