Computer Things


See other articles in the “Elixir” topic.

A relatively new feature of Phoenix is verified routes, which lets you create routes with the ~p sigil that result in compiler warnings when the route is invalid. For example, ~p"/users/new" will fail if there is no such path defined.

You can sprinkle your code with ~p sigils, but I’ve found that there are advantages to having a module that contains functions for each path in your project, like this:

defmodule Web.Paths do
  use Web, :verified_routes

  @customer_id "58-gkjScjj8"

  def home, do: ~p"/"
  def invitation(%Schema.User{type: admin} = user), do: ~p"/admin/invitation/#{}"
  def invitation(user), do: ~p"/invitation/#{}"
  def login, do: ~p"/auth/login"
  def logo, do: static("images/logo.png")
  def remote_auth, do: "{@customer_id}/auth"
  def styleguide(module, function), do: ~p"/styleguide/#{module}/#{function}"

Note that in this example, the module is Web.Paths, not MyAppWeb.Paths. See Phoenix Project Layout for more info.

More things to note:

  • As a plain module with functions, your editor can autocomplete your routes.
  • The functions usually fit on a single line, so you can see a lot more routes at a time.
  • A different invitation path is returned by pattern matching on the user type which reduces the need for duplicated code that chooses the correct route.
  • The logo isn’t a ~p sigil but using the generated route works the same as other routes.
  • Function parameters are listed so it’s easy to tell what’s required.
  • You can name your functions something that’s more meaningful than the path or URL.