Add the API to show the Links model or models.

CHANGELOG.org

@@ -17,4 +17,6 @@
     Added the simple index page.
 ** 0.3.2 <2023-07-09 Sun>
     Added the simple dev configuration.
+** 0.4.0 <2023-07-28 Fri>
+    Added the API to show the Links model or models.
 

lib/link_shortener_web/controllers/api/v1/links_controller.ex

@@ -0,0 +1,17 @@
+defmodule LinkShortenerWeb.Api.V1.LinksController do
+  use LinkShortenerWeb, :controller
+
+  alias LinkShortener.Links
+
+  action_fallback LinkShortenerWeb.FallbackController
+
+  def index(conn, _params) do
+    links = Links.get_all({})
+    render(conn, "index.json", links: links)
+  end
+
+  def show(conn, %{"id" => id}) do
+    link = Links.get_one(id)
+    render(conn, "show.json", links: link)
+  end
+end

lib/link_shortener_web/controllers/fallback_controller.ex

@@ -0,0 +1,24 @@
+defmodule LinkShortenerWeb.FallbackController do
+  @moduledoc """
+  Translates controller action results into valid `Plug.Conn` responses.
+
+  See `Phoenix.Controller.action_fallback/1` for more details.
+  """
+  use LinkShortenerWeb, :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(LinkShortenerWeb.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(LinkShortenerWeb.ErrorView)
+    |> render(:"404")
+  end
+end

lib/link_shortener_web/router.ex

@@ -22,9 +22,13 @@ defmodule LinkShortenerWeb.Router do
   end
 
   # Other scopes may use custom stacks.
-  # scope "/api", LinkShortenerWeb do
-  #   pipe_through :api
-  # end
+  scope "/api", LinkShortenerWeb do
+    pipe_through :api
+
+    scope "/v1", Api.V1, as: :v1 do
+      resources "/links", LinksController, except: [:new, :edit]
+    end
+  end
 
   # Enables LiveDashboard only for development
   #

lib/link_shortener_web/views/api/v1/links_view.ex

@@ -0,0 +1,21 @@
+defmodule LinkShortenerWeb.Api.V1.LinksView do
+  use LinkShortenerWeb, :view
+  alias LinkShortenerWeb.Api.V1.LinksView
+
+  def render("index.json", %{links: links}) do
+    %{data: render_many(links, LinksView, "link.json")}
+  end
+
+  def render("show.json", %{links: link}) do
+    %{data: render_one(link, LinksView, "link.json")}
+  end
+
+  def render("link.json", %{links: link}) do
+    %{
+      id: link.id,
+      name: link.name,
+      url: link.url,
+      shorten: link.shorten
+    }
+  end
+end

lib/link_shortener_web/views/changeset_view.ex

@@ -0,0 +1,19 @@
+defmodule LinkShortenerWeb.ChangesetView do
+  use LinkShortenerWeb, :view
+
+  @doc """
+  Traverses and translates changeset errors.
+
+  See `Ecto.Changeset.traverse_errors/2` and
+  `LinkShortenerWeb.ErrorHelpers.translate_error/1` for more details.
+  """
+  def translate_errors(changeset) do
+    Ecto.Changeset.traverse_errors(changeset, &translate_error/1)
+  end
+
+  def render("error.json", %{changeset: changeset}) do
+    # When encoded, the changeset returns its errors
+    # as a JSON object. So we just pass it forward.
+    %{errors: translate_errors(changeset)}
+  end
+end