relax v0.3.0 → Overview → Relax → Resource → FetchOne

Relax.Resource.FetchOne behaviour

Include in your resource to respond to GET /:id.

Typically brought into your resource via use Relax.Resource.

FetchOne defines two callback behaviours, both of which have a default, overrideable implementation.

In addition this module uses Relax.Resource.Fetchable, for shared model lookup logic with Relax.Resource.FetchAll.

Types

id :: integer | String.t

Callbacks

fetch_one/2
(callback) # ↑

Specs:

  • fetch_one(Plug.Conn.t, id) :: Plug.Conn.t | %{}

Find a resource to return.

This should return a struct to be formatted. Nil responses will trigger 404s.

Examples:

# Ecto based on query:
def fetch_one(_conn, id), do: MyApp.Repo.get!(MyApp.Models.Post, id)

# Return model limited to the current_user
def fetch_one(conn), do 
  fetchable(conn)
  |> MyApp.Repo.get(id)
end

A conn may also be returned:

def fetch_one(conn), do: halt send_resp(conn, 401, "no post for you")

The default behaviour leverages fetchable/1 and attempts to find via Ecto if possible.

fetch_one_resource/2
(callback) # ↑

Specs:

  • fetch_one_resource(Plug.Conn.t, id) :: Plug.Conn.t

This callback can be used to completely override the fetch_one action.

It accepts a Plug.Conn and must return a Plug.Conn.t