adds live post comments

Author: elixirprogrammer

lib/reddit/comments.ex

@@ -0,0 +1,104 @@
+defmodule Reddit.Comments do
+  @moduledoc """
+  The Comments context.
+  """
+  import Ecto
+  import Ecto.Query, warn: false
+  alias Reddit.Repo
+
+  alias Reddit.Comments.Comment
+
+  @doc """
+  Returns the list of comments.
+
+  ## Examples
+
+      iex> list_comments()
+      [%Comment{}, ...]
+
+  """
+  def list_comments do
+    Repo.all(Comment)
+  end
+
+  @doc """
+  Gets a single comment.
+
+  Raises `Ecto.NoResultsError` if the Comment does not exist.
+
+  ## Examples
+
+      iex> get_comment!(123)
+      %Comment{}
+
+      iex> get_comment!(456)
+      ** (Ecto.NoResultsError)
+
+  """
+  def get_comment!(id), do: Repo.get!(Comment, id)
+
+  @doc """
+  Creates a comment.
+
+  ## Examples
+
+      iex> create_comment(%{field: value})
+      {:ok, %Comment{}}
+
+      iex> create_comment(%{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def create_comment(user, post, comment) do
+    c = Ecto.build_assoc(user, :comments, comment)
+    Ecto.build_assoc(post, :comments, c)
+    |> Repo.insert()
+  end
+
+  @doc """
+  Updates a comment.
+
+  ## Examples
+
+      iex> update_comment(comment, %{field: new_value})
+      {:ok, %Comment{}}
+
+      iex> update_comment(comment, %{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def update_comment(%Comment{} = comment, attrs) do
+    comment
+    |> Comment.changeset(attrs)
+    |> Repo.update()
+  end
+
+  @doc """
+  Deletes a comment.
+
+  ## Examples
+
+      iex> delete_comment(comment)
+      {:ok, %Comment{}}
+
+      iex> delete_comment(comment)
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def delete_comment(%Comment{} = comment) do
+    Repo.delete(comment)
+  end
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for tracking comment changes.
+
+  ## Examples
+
+      iex> change_comment(comment)
+      %Ecto.Changeset{data: %Comment{}}
+
+  """
+  def change_comment(%Comment{} = comment, attrs \\ %{}) do
+    Comment.changeset(comment, attrs)
+  end
+end

lib/reddit/comments/comment.ex

@@ -0,0 +1,22 @@
+defmodule Reddit.Comments.Comment do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  alias Reddit.Users.User
+  alias Reddit.Community.Post
+
+  schema "comments" do
+    field :body, :string
+    belongs_to :user, User
+    belongs_to :post, Post
+
+    timestamps()
+  end
+
+  @doc false
+  def changeset(comment, attrs) do
+    comment
+    |> cast(attrs, [:body])
+    |> validate_required([:body])
+  end
+end

lib/reddit/community.ex

@@ -102,5 +102,4 @@ defmodule Reddit.Community do
   def change_post(%Post{} = post, attrs \\ %{}) do
     Post.changeset(post, attrs)
   end
-
 end

lib/reddit/community/post.ex

@@ -4,23 +4,25 @@ defmodule Reddit.Community.Post do
 
   alias Reddit.Category.Community
   alias Reddit.Users.User
+  alias Reddit.Comments.Comment
 
   schema "posts" do
     field :body, :string
     field :title, :string
     field :upvotes, :integer, default: 0
     field :downvotes, :integer, default: 0
-    field :comments, :integer, default: 0
+    field :comments_count, :integer, default: 0
     belongs_to :community, Community
     belongs_to :user, User
+    has_many :comments, Comment
 
     timestamps()
   end
 
   @doc false
   def changeset(post, attrs) do
     post
-    |> cast(attrs, [:title, :body, :upvotes, :downvotes, :comments])
+    |> cast(attrs, [:title, :body, :upvotes, :downvotes, :comments_count])
     |> validate_required([:title, :body])
   end
 end

lib/reddit/users/user.ex

@@ -12,6 +12,7 @@ defmodule Reddit.Users.User do
   alias Reddit.Category.Community
   alias Reddit.Community.Subscription
   alias Reddit.Community.Post
+  alias Reddit.Comments.Comment
 
   schema "users" do
     pow_user_fields()
@@ -23,6 +24,7 @@ defmodule Reddit.Users.User do
     has_many :communities, Community
     has_many :subscriptions, Subscription
     has_many :posts, Post
+    has_many :comments, Comment
 
     timestamps()
   end

lib/reddit_web/controllers/post_controller.ex

@@ -9,7 +9,7 @@ defmodule RedditWeb.PostController do
   alias Reddit.Repo
 
   def show(conn, %{"id" => id}) do
-    post = CommunityPost.get_post!(id) |> Repo.preload(:community)
+    post = CommunityPost.get_post!(id) |> Repo.preload([:community, :comments])
     render(conn, :show, post: post, community: post.community)
   end
 

lib/reddit_web/live/comments_live.ex

@@ -0,0 +1,52 @@
+defmodule RedditWeb.CommentsLive do
+  use RedditWeb, :live_view
+
+  alias Reddit.Comments
+  alias Reddit.Comments.Comment
+  alias Reddit.Repo
+  alias Reddit.Users.User
+  alias Reddit.Community
+
+  def mount(_params, %{"post" => post, "user_id" => user_id}, socket) do
+    changeset = Comments.change_comment(%Comment{})
+    comments = post.comments |> Repo.preload(:user)
+
+    socket =
+      assign(socket,
+        u_id: user_id,
+        p_id: post.id,
+        comments: comments,
+        changeset: changeset
+      )
+
+    {:ok, socket, temporary_assigns: [comments: []]}
+  end
+
+  def handle_event("save", %{"comment" => params}, socket) do
+    user = Repo.get!(User, params["u_id"])
+    post = Community.get_post!(params["p_id"])
+    comment = params |> Map.new(fn {k, v} -> {String.to_atom(k), v} end)
+    case Comments.create_comment(user, post, comment) do
+      {:ok, comment} ->
+        comment = comment |> Repo.preload(:user)
+        socket =
+          update(
+            socket,
+            :comments,
+            fn comments -> [comment | comments] end
+          )
+
+        changeset = Comments.change_comment(%Comment{})
+
+        socket = assign(socket, changeset: changeset)
+
+        :timer.sleep(500)
+
+        {:noreply, socket}
+
+      {:error, %Ecto.Changeset{} = changeset} ->
+        socket = assign(socket, changeset: changeset)
+        {:noreply, socket}
+    end
+  end
+end

lib/reddit_web/live/comments_live.html.leex

@@ -0,0 +1,24 @@
+<div id="comments" phx-update="append">
+    <%= for comment <- @comments do %>
+        <div class="comment" id="<%= comment.id %>">
+            <%= live_patch comment.user.full_name, to: Routes.user_path(@socket, :profile, comment.user.username) %>
+            <p><%= comment.body %></p>
+        </div>
+    <% end %>
+</div>
+
+
+<h5>Leave a comment</h5>
+
+<%= f = form_for @changeset, "#",
+  phx_submit: "save" %>
+
+  <%= textarea f, :body, class: "form-control" %>
+  <%= error_tag f, :body %>
+
+  <%= hidden_input f, :u_id, value: @u_id %>
+  <%= hidden_input f, :p_id, value: @p_id %>
+
+  <%= submit "Submit Comment", class: "btn btn-success mt-3",
+    phx_disable_with: "Saving..." %>
+</form>

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

@@ -11,58 +11,7 @@
 
     <%= text_to_html(@post.body, [wrapper_tag: :p]) %>
 
-    <div id="post-comments">
-      <div class="comment">
-        <a href="/u/davidb">David Battersby</a>
-        <p>Let me know what you guys think.</p>
-      </div>
-      <div class="comment">
-        <a href="/u/moskina">moskina moskina</a>
-        <p>adasdsad</p>
-      </div>
-      <div class="comment">
-        <a href="/u/moskina">moskina moskina</a>
-        <p>adasdsadsdasd</p>
-      </div>
-      <div class="comment">
-        <a href="/u/moskina">moskina moskina</a>
-        <p>adasdsadsdasddasdasd</p>
-      </div>
-      <div class="comment">
-        <a href="/u/testing">test testtest</a>
-        <p>test test</p>
-      </div>
-    </div>
-
-    <h5>Leave a comment</h5>
-    <form
-      class="new_comment"
-      id="new_comment"
-      action="/comments"
-      accept-charset="UTF-8"
-      data-remote="true"
-      method="post"
-    >
-      <input
-        value="1"
-        type="hidden"
-        name="comment[post_id]"
-        id="comment_post_id"
-      />
-      <textarea
-        placeholder="Your comment goes here"
-        class="form-control"
-        name="comment[message]"
-        id="comment_message"
-      ></textarea>
-      <input
-        type="submit"
-        name="commit"
-        value="Submit comment"
-        class="btn btn-success mt-3"
-        data-disable-with="Submit comment"
-      />
-    </form>
+    <%= live_render(@conn, RedditWeb.CommentsLive, session: %{"post" => @post, "user_id" => @current_user.id}) %>
   </div>
 </div>
 

priv/repo/migrations/20200804063125_create_comments.exs

@@ -0,0 +1,16 @@
+defmodule Reddit.Repo.Migrations.CreateComments do
+  use Ecto.Migration
+
+  def change do
+    create table(:comments) do
+      add :body, :text
+      add :user_id, references(:users, on_delete: :nothing)
+      add :post_id, references(:posts, on_delete: :nothing)
+
+      timestamps()
+    end
+
+    create index(:comments, [:user_id])
+    create index(:comments, [:post_id])
+  end
+end