Section specific auth checks for Phoenix 1.8 isn't working on my app - but works on 1.7

Phoenix Forum Questions / Help
,
1

In a liveview 1.7 app the code below works as expected. This makes the portion of the DOM render only when the user is authenticated.

defmodule AppWeb.Landing do
  use AppWeb, :live_view

  on_mount {AppWeb.UserAuth, :mount_current_user}  # Important part


  def mount(_params, _session, socket) do

    {:ok, socket}
  end

  def render(assigns) do


    ~H"""

    <div class="h-screen">


      <%= if @current_user do %>
          <h1>this is text for auth check</h1> 
      <% end %>

      </div>
    """ 
   end
  end

When I place the exact same code in a new phoenix 1.8 instance I get this:

[error] ** (FunctionClauseError) no function clause matching in AppWeb.UserAuth.on_mount/4
    (app 0.1.0) lib/app_web/user_auth.ex:156: AppWeb.UserAuth.on_mount(:mount_current_user, %{}, %{"_csrf_token" => "vkKX5N_I4AZCmGNG1yDUnxQ5"}, #Phoenix.LiveView.Socket<id: "phx-GDgk8lYlgWTv4AbE", endpoint: AppWeb.Endpoint, view: AppWeb.Landing, parent_pid: nil, root_pid: nil, router: AppWeb.Router, assigns: %{__changed__: %{}, flash: %{}, live_action: :home}, transport_pid: nil, ...>)
    (phoenix_live_view 1.0.9) lib/phoenix_live_view/lifecycle.ex:158: anonymous fn/4 in Phoenix.LiveView.Lifecycle.mount/3
    (phoenix_live_view 1.0.9) lib/phoenix_live_view/lifecycle.ex:237: Phoenix.LiveView.Lifecycle.reduce_socket/3
    (phoenix_live_view 1.0.9) lib/phoenix_live_view/utils.ex:346: anonymous fn/6 in Phoenix.LiveView.Utils.maybe_call_live_view_mount!/5

The on_mount function (shown below) is in the file named user_auth.ex and under the module named: AppWeb.UserAuth

  def on_mount(:mount_current_scope, _params, session, socket) do
    {:cont, mount_current_scope(socket, session)}
  end
2

I screwed up and looked at the wrong file for reference.

But I figured out how to solve it.

Use “scope”

  use AppWeb, :live_view

  alias App.Repo

  on_mount {AppWeb.UserAuth, :mount_current_scope}  # Important part
   
  def mount(_params, _session, socket) do

    {:ok, socket}
  end

  def render(assigns) do

    ~H"""

      <div class="h-screen">
        <%= if @current_scope do %>
            <h1>this is text for auth check</h1> 
        <% end %>
      </div>
 

    """
  end
end