adds member function to category context

Author: elixirprogrammer

lib/reddit/category.ex

@@ -2,10 +2,9 @@ defmodule Reddit.Category do
   @moduledoc """
   The Category context.
   """
+  import Ecto
 
-  import Ecto.Query, warn: false
   alias Reddit.Repo
-
   alias Reddit.Category.Community
 
   @doc """
@@ -107,4 +106,10 @@ defmodule Reddit.Category do
     Community.changeset(community, attrs)
   end
 
+  def members(community) do
+    community
+    |> assoc(:subscriptions)
+    |> Repo.aggregate(:count, :user_id)
+  end
+
 end

lib/reddit_web/controllers/community_controller.ex

@@ -34,10 +34,11 @@ defmodule RedditWeb.CommunityController do
   end
 
   def show(conn, %{"name" => name}) do
-    community = Repo.get_by(Community, name: name) |> Repo.preload(:subscriptions)
+    community = Repo.get_by(Community, name: name)
+    members = Category.members(community)
 
     if community do
-      render(conn, "show.html", community: community)
+      render(conn, "show.html", community: community, members: members)
     else
       redirect(conn, to: "/")
     end

lib/reddit_web/templates/community/show.html.eex

@@ -40,7 +40,7 @@
     <div class="card p-3">
       <p class="h5">About this community</p>
       <p class="mt-2"><%= @community.summary %></p>
-      <p><%= pluralize "member", length(@community.subscriptions)  %></p>
+      <p><%= pluralize "member", @members  %></p>
     </div>
 
     <div class="p-3">