Having trouble with the Phoenix Getting Started guide - router.ex getting double path prefix to controller

Phoenix Forum Questions / Help
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1

I’m following the directions for the Getting Started project at hexdocs.pm. I’ve gotten to the guide on Contexts here: https://hexdocs.pm/phoenix/contexts.html. I’ve added a resources line to my router.ex so that my “/” scope looks like this:

scope "/", HelloWeb do
    pipe_through :browser

    get "/", PageController, :home
    get "/hello", HelloController, :index
    get "/hello/:messenger", HelloController, :show
    resources "/products", ProductController
  end

But instead of getting routes that point to HelloWeb.ProductController, my routes all point to HelloWeb.HelloWeb.ProductController. Even more strange, if I put in the name of some other non-existent controller I get routes that look the way I expected. Is there something about the generated ProductController that is prepending an extra HelloWeb onto the generated routes?

Any idea what I’m doing wrong here?

EDIT to add an example of what I mean. If I change that line to resources "/products", NilController then my resulting mix phx.routes looks like this:

GET     /products                              HelloWeb.NilController :index
GET     /products/:id/edit                     HelloWeb.NilController :edit
GET     /products/new                          HelloWeb.NilController :new
GET     /products/:id                          HelloWeb.NilController :show
POST    /products                              HelloWeb.NilController :create
PATCH   /products/:id                          HelloWeb.NilController :update
PUT     /products/:id                          HelloWeb.NilController :update
DELETE  /products/:id                          HelloWeb.NilController :delete
2

Can you post the full router.exs file? :slight_smile:

3

I think I found the problem @josevalim. Either my editor or the context generator or my cat added alias HelloWeb.ProductController to the top of router.ex. When I comment that line out I no longer have the problem.

defmodule HelloWeb.Router do
  alias HelloWeb.ProductController
  use HelloWeb, :router

  pipeline :browser do
    plug :accepts, ["html"]
    plug :fetch_session
    plug :fetch_live_flash
    plug :put_root_layout, html: {HelloWeb.Layouts, :root}
    plug :protect_from_forgery
    plug :put_secure_browser_headers
  end

  pipeline :api do
    plug :accepts, ["json"]
  end

  scope "/", HelloWeb do
    pipe_through :browser

    get "/", PageController, :home
    get "/hello", HelloController, :index
    get "/hello/:messenger", HelloController, :show
    resources "/products", ProductController
  end

  # Other scopes may use custom stacks.
  # scope "/api", HelloWeb do
  #   pipe_through :api
  # end

  # Enable LiveDashboard and Swoosh mailbox preview in development
  if Application.compile_env(:hello, :dev_routes) do
    # If you want to use the LiveDashboard in production, you should put
    # it behind authentication and allow only admins to access it.
    # If your application does not have an admins-only section yet,
    # you can use Plug.BasicAuth to set up some basic authentication
    # as long as you are also using SSL (which you should anyway).
    import Phoenix.LiveDashboard.Router

    scope "/dev" do
      pipe_through :browser

      live_dashboard "/dashboard", metrics: HelloWeb.Telemetry
      forward "/mailbox", Plug.Swoosh.MailboxPreview
    end
  end
end

That wont cause any future problems for me if I comment out that second line, will it?

1 Like
4

Remove the alias in line 2.

It was probably added by the editor automatically (although mistakenly) when you tried to add the resources. This issue happened to me once and I went crazy trying to figure out what happened.

3 Likes
5

I hate that feature so much, those auto-added aliases has tripped me up a few times as well. If you don’t see it happen you will start to get errors that doesn’t seem to make any sense at all.

1 Like