Hello. I have a question about design of phoenix api server.
I am developing a web application, and using phoenix as a backend server for it. I saw some open source repositories as examples, but I still don’t know what is a good way to determine a design. I will take papercups chat api as an example of phoenix server.
Question
I think phoenix consists of controller, view, and schema file, query file. In the below examples, elixir reads information from database with query and schema, pass the information to controller, and shape it as a json in the view. The view returns most of user information except for preloaded data such as settings, profile, then I got 2 questions of it.
-
Should API Server only provide information which is required by front-end as a response?
The view contains most ofuserinformation as I said. Although I’m not sure how the front-end is, I don’t think the all fields ofrender("user.json", %{user: user})are necessary in all cases to handle user information in front-end. Do I not need to prepare a view per a kind of request from front-end? -
Should I refrain from frequent use of preload?
get_user_info/2returns not onlyuserinformation but also preloaded data. But the preloaded data are unused in view. Should I prepare another function which does not preload data In such case? Or does it depend on information like table size, count of foreign keys, and so on?
Query
@spec get_user_info(binary(), integer()) :: User.t() | nil
def get_user_info(account_id, user_id) do
User
|> where(id: ^user_id, account_id: ^account_id)
|> Repo.one()
|> Repo.preload([:profile, :settings])
end
Schema
schema "users" do
field(:email_confirmation_token, :string)
field(:password_reset_token, :string)
field(:email_confirmed_at, :utc_datetime)
field(:disabled_at, :utc_datetime)
field(:archived_at, :utc_datetime)
field(:role, :string, default: "user")
field(:has_valid_email, :boolean)
has_many(:conversations, Conversation, foreign_key: :assignee_id)
has_many(:messages, Message, foreign_key: :user_id)
belongs_to(:account, Account, type: :binary_id)
has_one(:profile, UserProfile)
has_one(:settings, UserSettings)
has_many(:mentions, Mention)
has_many(:mentioned_conversations, through: [:mentions, :conversation])
has_many(:mentioned_messages, through: [:mentions, :message])
pow_user_fields()
timestamps()
end
Controller
@spec show(Plug.Conn.t(), map) :: Plug.Conn.t()
def show(conn, %{"id" => id}) do
user = ChatApi.Users.get_user_info(conn.assigns.current_user.account_id, id)
render(conn, "show.json", user: user)
end
View
def render("show.json", %{user: user}) do
%{data: render_one(user, UserView, "user.json")}
end
def render("user.json", %{user: user}) do
case user do
%{profile: %UserProfile{} = profile} ->
%{
id: user.id,
object: "user",
email: user.email,
created_at: user.inserted_at,
disabled_at: user.disabled_at,
archived_at: user.archived_at,
full_name: profile.full_name,
display_name: profile.display_name,
profile_photo_url: profile.profile_photo_url,
role: user.role
}
_ ->
%{
id: user.id,
object: "user",
email: user.email,
created_at: user.inserted_at,
disabled_at: user.disabled_at,
archived_at: user.archived_at,
role: user.role
}
end
end
Thank you.
