Compilation error when running ecto.migrate after import of phx.gen.auth

Hello,
I am very new to Phoenix and Elixir and currently trying to build a new Web App using Phoenix 1.6.
I am following the guide https://hexdocs.pm/phoenix/mix_phx_gen_auth.html#content to use the gen.auth.

mix deps.get

works fine and returns:

All dependencies are up to date

The next step is to run:

mix ecto.setup

At this point, the following error is triggered:

Compilation error in file lib/testproject_web/views/user_confirmation_view.ex ==
** (CompileError) lib/testproject_web/templates/user_confirmation/edit.html.heex:1: undefined function form/1
    (elixir 1.12.3) src/elixir_locals.erl:114: anonymous fn/3 in :elixir_locals.ensure_no_undefined_local/3
    (stdlib 3.12) erl_eval.erl:680: :erl_eval.do_apply/6
    (elixir 1.12.3) lib/kernel/parallel_compiler.ex:319: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/7

Version of Elixir and Phoenix are up-to-date.

Does anyone have an idea how to fix this error? I have not found anything useful on the internet yet.

Thank you for any help!

Can you show the contents of file templates/user_confirmation/edit.html.heex:1 for us to see?

Thanks for the reply. There it is:

<h1>Confirm account</h1>

<.form let={_f} for={:user} action={Routes.user_confirmation_path(@conn, :update, @token)}>
  <div>
    <%= submit "Confirm my account" %>
  </div>
</.form>

<p>
  <%= link "Register", to: Routes.user_registration_path(@conn, :new) %> |
  <%= link "Log in", to: Routes.user_session_path(@conn, :new) %>
</p>

It didn’t change here anything. It’s a generated file from gen.auth.

OK great - that form/1 comes from Phoenix.LiveView.Helpers. So let’s make sure that is being properly imported. The first step is to the View:

# lib/testproject_web/views/user_confirmation_view.ex
defmodule TestprojectWeb.UserConfirmationView do
  use TestprojectWeb, :view
end

This tells us where the imports are being defined - in TestprojectWeb.view. So let’s check that out:

# lib/testproject_web.ex
defmodule TestprojectWeb do
  ...
  def view do
    quote do
      use Phoenix.View,
        root: "lib/testproject_web/templates",
        namespace: TestprojectWeb

      # Import convenience functions from controllers
      import Phoenix.Controller,
        only: [get_flash: 1, get_flash: 2, view_module: 1, view_template: 1]

      # Include shared imports and aliases for views
      unquote(view_helpers())
    end
  end
  ...
end

The very last part is what we’re looking for - the shared imports. But that comes from yet another function called view_helpers, which is here in the same file. Scroll down further and you should find

# lib/testproject_web.ex
defp view_helpers do
  quote do
    # Use all HTML functionality (forms, tags, etc)
    use Phoenix.HTML

    # Import LiveView and .heex helpers (live_render, live_patch, <.form>, etc)
    import Phoenix.LiveView.Helpers

    # Import basic rendering functionality (render, render_layout, etc)
    import Phoenix.View

    import TestprojectWeb.ErrorHelpers
    import TestprojectWeb.Gettext
    alias TestprojectWeb.Router.Helpers, as: Routes
  end
end

And there is Phoenix.LiveView.Helpers being imported! Note the comment even mentions the <.form> helper included.

Hopefully at some point in this process, you found something was missing, and could use the examples above to remedy the issue. If not - if everything is already there, and you’re still getting the missing form/1 error - then we can try some other possibilities next.

5 Likes

Thank you very much for your great help! The import import Phoenix.LiveView.Helpers was missing. Now the errors are resolved. Thanks again!

2 Likes

great explanation

1 Like