From `Repo.insert/2` to `Repo.transaction/2`

Questions & Help Questions
, ,
1

I have to convert the following code using Repo.insert/2

def create_question(attrs) do
  %Question{}
  |> Question.creation_changeset(attrs)
  |> Repo.insert()
end

to use a transaction:

def create_question(attrs) do
  question_changeset =
    Question.creation_changeset(%Question{}, attrs)

  Multi.new()
  |> Multi.insert(:question, question_changeset)
  |> Multi.run(:do_something, fn _repo, %{question: question} ->
    # do something
    {:ok, nil}
  end)
  |> Repo.transaction()
end

The problem is that now I have to change the code of my controller because the return value of Repo.transaction/2 is different than the return value of Repo.insert/2.

The controller’s action code is the following:

def create(conn, %{"question" => question_params}) do
  case Quiz.create_question(question_params) do
    {:ok, question} ->
      conn
      |> put_flash(:info, "Question created successfully.")
      |> redirect(to: Routes.admin_question_path(conn, :show, question))

    {:error, %Ecto.Changeset{} = changeset} ->
      render(conn, "new.html", changeset: changeset)
  end
end

I think it’s wrong to change controller’s code whether I use a transaction or not? I think that the controller always either needs a struct or a changeset to display the errors, just as Repo.insert/2 returns?

Any advice is welcome on how to refactor that properly, on where I have to change code.