Add guards on post resources

lib/aggiedit/roles.ex

@@ -0,0 +1,10 @@
+defmodule Aggiedit.Roles do
+  alias Aggiedit.Accounts.User
+  alias Aggiedit.Rooms.Post
+
+  def guard?(user, action, object)
+  def guard?(%User{role: :admin}, _, _), do: true
+  def guard?(%User{room_id: rid}, :show, %Post{room_id: rid}), do: true
+  def guard?(%User{id: id, room_id: rid}, action, %Post{user_id: id, room_id: rid}) when action in [:delete, :edit], do: true
+  def guard?(_, _, _), do: false
+end

lib/aggiedit_web/live/post_live/index.ex

@@ -1,6 +1,7 @@
 defmodule AggieditWeb.PostLive.Index do
   use AggieditWeb, :live_view
 
+  alias Aggiedit.Roles
   alias Aggiedit.Rooms
   alias Aggiedit.Rooms.Post
   alias Aggiedit.Repo
@@ -14,12 +15,24 @@ defmodule AggieditWeb.PostLive.Index do
     end
   end
 
+  @impl true
+  def handle_params(%{"id" => id}=params, _url, socket) do
+    post = Rooms.get_post!(id)
+    if Roles.guard?(socket.assigns.current_user, socket.assigns.live_action, post) do
+      {:noreply, apply_action(socket, socket.assigns.live_action, params)}
+    else
+      {:noreply, socket |> put_flash(:error, "You do not have permission to edit this post.") |> redirect(to: Routes.post_index_path(socket, :index))}
+    end
+  end
+
   @impl true
   def handle_params(params, _url, socket) do
+    IO.puts(inspect(params))
     {:noreply, apply_action(socket, socket.assigns.live_action, params)}
   end
 
-  defp apply_action(socket, :edit, %{"id" => id}) do
+
+  defp apply_action(socket, :edit, %{"id" => id}=params) do
     socket
     |> assign(:page_title, "Edit Post")
     |> assign(:post, Rooms.get_post!(id) |> Repo.preload(:upload))
@@ -40,9 +53,12 @@ defmodule AggieditWeb.PostLive.Index do
   @impl true
   def handle_event("delete", %{"id" => id}, socket) do
     post = Rooms.get_post!(id)
-    {:ok, _} = Rooms.delete_post(post)
-
-    {:noreply, assign(socket, :posts, list_posts())}
+    if Roles.guard?(socket.assigns.current_user, :delete, post) do
+      Rooms.delete_post(post)
+      {:noreply, socket |> put_flash(:success, "Post deleted.") |> redirect(to: Routes.post_index_path(socket, :index))}
+    else
+      {:noreply, socket |> put_flash(:error, "You do not have permission to delete this post.") |> redirect(to: Routes.post_index_path(socket, :index))}
+    end
   end
 
   defp list_posts do

lib/aggiedit_web/live/post_live/show.ex

@@ -2,18 +2,30 @@ defmodule AggieditWeb.PostLive.Show do
   use AggieditWeb, :live_view
 
   alias Aggiedit.Rooms
+  alias Aggiedit.Roles
+  alias Aggiedit.Repo
 
   @impl true
-  def mount(_params, _session, socket) do
-    {:ok, socket}
+  def mount(_params, session, socket) do
+    socket = assign_socket_user(session, socket)
+    case socket.assigns do
+      %{:current_user => user} -> {:ok, socket}
+      _ -> {:ok, socket |> put_flash(:error, "You must log in to access this page.") |> redirect(to: Routes.user_session_path(socket, :new))}
+    end
   end
 
   @impl true
   def handle_params(%{"id" => id}, _, socket) do
+    post = Rooms.get_post!(id)
+    |> Repo.preload(:upload)
+    if Roles.guard?(socket.assigns.current_user, socket.assigns.live_action, post) do
       {:noreply,
       socket
       |> assign(:page_title, page_title(socket.assigns.live_action))
-     |> assign(:post, Rooms.get_post!(id))}
+      |> assign(:post, post)}
+    else
+      {:noreply, socket |> put_flash(:error, "You don't have permission to do that.") |> redirect(to: Routes.post_show_path(socket, :index))}
+    end
   end
 
   defp page_title(:show), do: "Show Post"

lib/aggiedit_web/live/post_live/show.html.heex

@@ -5,6 +5,7 @@
     <.live_component
       module={AggieditWeb.PostLive.FormComponent}
       id={@post.id}
+      current_user={@current_user}
       title={@page_title}
       action={@live_action}
       post={@post}

priv/repo/migrations/20220405071636_create_users_auth_tables.exs

@@ -14,7 +14,7 @@ defmodule Aggiedit.Repo.Migrations.CreateUsersAuthTables do
       timestamps()
     end
 
-    create unique_index(:users, [:email])
+    create unique_index(:users, [:email, :username])
 
     create table(:users_tokens) do
       add :user_id, references(:users, on_delete: :delete_all), null: false