adding comment model

Author: Willian Yassunaka

discuss/priv/repo/migrations/20170905155136_add_comments.exs

@@ -0,0 +1,13 @@
+defmodule Discuss.Repo.Migrations.AddComments do
+  use Ecto.Migration
+
+  def change do
+    create table(:comments) do
+      add :content, :string
+      add :user_id, references(:users)
+      add :topic_id, references(:topics)
+
+      timestamps()
+    end
+  end
+end

discuss/web/controllers/topic_controller.ex

@@ -10,6 +10,11 @@ defmodule Discuss.TopicController do
     render conn, "index.html", topics: topics
   end
 
+  def show(conn, %{"id" => topic_id}) do
+    topic = Repo.get!(Topic, topic_id)
+    render conn, "show.html", topic: topic
+  end
+
   def new(conn, _params) do
     changeset = Topic.changeset(%Topic{}, %{})
 

discuss/web/models/comment.ex

@@ -0,0 +1,17 @@
+defmodule Discuss.Comment do
+  use Discuss.Web, :model
+  
+  schema "comments" do
+    field :content, :string
+    belongs_to :user, Discuss.User
+    belongs_to :topic, Discuss.Topic
+
+    timestamps()    
+  end
+
+  def changeset(struct, params \\ %{}) do
+    struct
+    |> cast(params, [:content])
+    |> validate_required([:content])    
+  end
+end

discuss/web/models/topic.ex

@@ -4,6 +4,7 @@ defmodule Discuss.Topic do
   schema "topics" do
     field :title, :string
     belongs_to :user, Discuss.User
+    has_many :comments, Discuss.Comment
   end
 
   def changeset(struct, params \\ %{}) do

discuss/web/models/user.ex

@@ -6,6 +6,7 @@ defmodule Discuss.User do
     field :provider, :string
     field :token, :string
     has_many :topics, Discuss.Topic
+    has_many :comments, Discuss.Comment
 
     timestamps()
   end

discuss/web/templates/topic/index.html.eex

@@ -3,7 +3,7 @@
 <ul class="collection">
   <%= for topic <- @topics do %>
     <li class="collection-item">
-      <%= topic.title %>
+      <%= link topic.title, to: topic_path(@conn, :show, topic) %>
 
       <%= if @conn.assigns.user.id == topic.user_id do %>
       <div class="right">

discuss/web/templates/topic/show.html.eex

@@ -0,0 +1 @@
+<%= @topic.title %>