# 401 Unauthorized
send_resp(conn, 401, '')
send_resp(conn, :unauthorized, '') # same as above
If an error is raised during controller, its a 500
Development Errors
Phoenix auto creates a nice html page for raise errors in dev
dev.exs
config :react_phoenix, ReactPhoenixWeb.Endpoint,
http: [port: 4000],
debug_errors: false, #to disable for api endpoints
In prod, will be used. Ecto.NoResultsError in ecto will be translated to 404, but everything else is usually a 500.
If you return a non conn, will be 500 orrr
Is not triggered when an error is raised, only when conn returns an error like in a with statement
Transforms nonconn response to valid conn response
defmodule MyController do
use Phoenix.Controller
action_fallback MyFallbackController
def show(conn, %{"id" => id}, current_user) do
with {:ok, post} <- Blog.fetch_post(id),
:ok <- Authorizer.authorize(current_user, :view, post) do
render(conn, "show.json", post: post)
end
end
end
If with fails, it just returns the unmatched value which probably has{:error, ....} in it. So in fallback controller
defmodule ReactPhoenixWeb.FallbackController do
@moduledoc """
Translates controller action results into valid `Plug.Conn` responses.
See `Phoenix.Controller.action_fallback/1` for more details.
"""
use ReactPhoenixWeb, :controller
# This clause handles errors returned by Ecto's insert/update/delete.
def call(conn, {:error, %Ecto.Changeset{} = changeset}) do
conn
|> put_status(:unprocessable_entity)
|> put_view(ReactPhoenixWeb.ChangesetView)
|> render("error.json", changeset: changeset)
end
# This clause is an example of how to handle resources that cannot be found.
def call(conn, {:error, :not_found}) do
conn
|> put_status(:not_found)
|> put_view(ReactPhoenixWeb.ErrorView)
|> render(:"404")
end
end
