Elixir example

omdb_practice.ex

defmodule HelloPhoenix.MoviesController do
  use HelloPhoenix.Web, :controller
  require Logger

  def show(conn, %{"id" => query}) do

    results = fetch_by_id(query)

    # results is a hash that might have a key named "Error"
    # in which case we need to try to query by title instead of id

    # Old Code that works:
    # if elem(results, 1)["Error"] != nil do
    #   results = fetch_by_title(query)
    # end

    # This does not work, and feels silly anyway
    # The first attempt to detect the "Error" doesn't work
    # And without the no-op line, I get
    # "no case clause matching: {:ok, %{"Actors" => "Tom H..."
    case elem(results,1) do
      { "Error", _ } -> results = fetch_by_title(query)
      _ -> # noop
    end

    { :ok, movie } = results

    render conn, "show.html", movie: movie
  end

  defp find_by_id_url(id) do
    "http://omdbapi.com/?i=#{id}"
  end

  defp find_by_title_url(title) do
    "http://omdbapi.com/?t=#{title}"
  end

  def fetch_by_id(id) do
    find_by_id_url(id) |> HTTPoison.get |> handle_response
  end

  def fetch_by_title(title) do
    find_by_title_url(title) |> HTTPoison.get |> handle_response
  end

  defp handle_response({:ok, %HTTPoison.Response{body: body}}) do
    results = Poison.decode body
  end

  defp handle_response({:error, %HTTPoison.Error{reason: reason}}) do
    { :error, reason }
  end

end

case get_movie(query) do
  {:error, message} -> redirect...
  {ok, data} -> render...
end

defp get_movie(query) do
  fetch_by_id(query) 
  |> process_query query
end

defp process_query({:error, _}, query) do
  fetch_by_title(query)
end

defp process_query({:ok, data}, query), do: data