Understanding Phoenix router

[peerreynders]

While I’m not sure that it addresses you concerns directly, it may clarify some related grey areas:

Question about Plug from the Programming Phoenix book

The long version: It would be more accurate to say that a Plug involves some kind of function that satisfies the (Plug.Conn.t, Plug.opts) :: Plug.Conn.t type signature. The documentation is also clear that: From what I can tell the 2nd parameter on (Plug.Conn.t, Plug.opts) :: Plug.Conn.t is useless (***) with a function plug - it exists only for compatibility with the module plug. The documentation’s example module plug looks like this: defmodule MyPlug do import Plug.Conn def init(o…

In addition I’d recommend exploring the Elixir compilation process a bit - to start have a look at

https://medium.com/@fxn/how-does-elixir-compile-execute-code-c1b36c9ec8cf