Installation Instructions Missing about jsonapi HOT 9 CLOSED

defp deps do
  [{:jsonapi, "~> 0.1.0"}]
end

defmodule HelloWeb.UserView do
  use HelloWeb, :view

  alias HelloWeb.UserView, as: UserView

  def render("index.json", %{users: users}) do
    %{data: render_many(users, UserView, "user.json")}
  end

  def render("show.json", %{user: user}) do
    %{data: render_one(user, UserView, "user.json")}
  end

  def render("user.json", %{user: user}) do
    %{id: user.id,
      email: user.email,
      password: user.password}
  end
end

# two methods from user controller
def index(conn, _params) do
  users = Accounts.list_users()
  render(conn, "index.json", users: users)
end

def show(conn, %{"id" => id}) do
  user = Accounts.get_user!(id)
  render(conn, "show.json", user: user)
end

defmodule HelloWeb.UserView do
  use HelloWeb, :view
  use JSONAPI.View, type: "users"

  alias HelloWeb.UserView, as: UserView

  def fields() do
    [:email]
  end

  def render("index.json", %{users: users}) do
    %{data: render_many(users, UserView, "user.json")}
  end

  def render("show.json", %{user: user}) do
    %{data: render_one(user, UserView, "user.json")}
  end

  def render("user.json", %{user: user}) do
    %{id: user.id,
      email: user.email
    }
  end
end

defmodule HelloWeb.UserView do
  use HelloWeb, :view
  use JSONAPI.View, type: "users"

  def fields() do
    [:email]
  end
end

# user controller
plug JSONAPI.QueryParser,
  filter: ~w(age),
  sort: ~w(created_at email),
  view: HelloWeb.UserView

def index(conn, _params) do
  sort = conn.assigns.jsonapi_query.sort
  render(conn, "index.json", data: Accounts.list_users_sorted(sort))
end

# context
def list_users_sorted(sort) do
  Repo.all(User |> order_by(^sort))
end

defmodule JSONAPI.Includes do
  def call(%{method: "POST"} = conn, _), do: conn
  def call(%{assigns: %{jsonapi_query: query}, private: %{resource: resource}} = conn, opts) do
    repo = Keyword.fetch!(opts, :repo)
    resource = repo.preload(resource, normalize_includes(query.includes))

    Plug.Conn.put_private(conn, :resource, resource)
  end
  def call(conn, _), do: conn

  defp normalize_include(include) when is_atom(include), do: include
  defp normalize_include({}), do: []
  defp normalize_include(include) when is_tuple(include) do
    parent = elem(include, 0)
    children = Tuple.delete_at(include, 0)
    Keyword.put([], parent, normalize_include(children))
  end

  defp normalize_includes(includes), do: Enum.map(includes, &normalize_include/1)
end

defmodule JSONAPI.Query do
  def call(%{assigns: %{jsonapi_query: jsonapi_query}} = conn, opts) do
      resource = Keyword.get(opts, :resource)
      repo = Keyword.fetch!(opts, :repo)
      filters = query_filters(jsonapi_query)

      resource
      |> select([r], r)
      |> order_by([r], ^jsonapi_query.sort)
      |> build_query(filters)
      |> repo.all
      |> handle_results(conn)
    end

    def call(conn, _opts) do
      conn
    end

    defp build_query(query, filters) when is_list(filters), do: Enum.reduce(filters, query, &build_query/2)
    defp build_query({k, v}, query) when is_list(v), do: where(query, [r], field(r, ^k) in ^v)
    defp build_query({k, v}, query), do: where(query, [r], field(r, ^k) == ^v)

    defp query_filters(%{filter: filters}), do: Enum.map(filters, &query_filter/1)

    defp query_filter({k, v}) when is_binary(v) do
      value =
        case String.split(v, ",") do
          [one] -> one
          list  -> list
        end

      {k, value}
    end
    defp query_filter(filter), do: filter  
end