Why is there a missing end statement in generated form?

Phoenix Forum Questions / Help
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1

Hi y’all. I’m trying to understand how Phoenix works but I’m seriously struggling with this. I’m trying to understand why this is valid code?

defmodule WorkoutGeneratorWeb.WorkoutHTML do
  use WorkoutGeneratorWeb, :html

  embed_templates "workout_html/*"

  @doc """
  Renders a workout form.
  """
  attr :changeset, Ecto.Changeset, required: true
  attr :action, :string, required: true

  def workout_form(assigns)
end

the workout_form/1 (?) has a missing end statement. This module was made from the typical generators (with no schema option).

answered by @sodapopcan. From the docs…

Embedded templates also support declarative assigns via bodyless function definitions, for example…

2

The answer is here.

In short, the body is defined from the heex template via macro magic.

A hint is that it’s not just missing and end but also a do. Maybe it’s too much info for now but a more “normal” example of this syntax in the wild is when defining multiple function heads that have a default pameter(s):

def foo(a, b \\ [])

def foo(:bar, b) do
  ["bar" | b]
end

def foo(:baz, b) do
  ["baz" | b]
end
3 Likes
3

It is the function signature…

As mentionned by @sodapopcan, there is no block (do…end)

1 Like
4

Thanks, I appreciate it. I guess it’s all about reading the docs more.

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5

Hey, it’s cool. It can be overwhelming at first, and I agree it’s odd syntax to come across when first learning the language. That’s all part of what this forum is for!

1 Like