RailsGuides - Getting Started with Rails. Add Comment validation

rubyonrails-docs
1

Hi everyone. I’m new to Rails so trying to read all the documentation.

While reading through the Getting Started with Rails I’ve noticed that there is no section about article Comments validation, but I think it would be great to have such chapter. It is hard for me to make it up for now, so I would appreciate any guidance on how to create Comment validation(mandatory author and body) and show errors of invalid submission to the user.
I’m looking for a way to do something like you suggest in Article validation, I’ve tried to modify it in some ways, but it didn’t work.
Thank you for any help.

3

Hi there! Here are two options that I try on how to validate comment inside an article based on Ruby on Rails guides.

  1. Slightly elegant way
# comments_controller.rb

def create
     @article = Article.find(params[:article_id])
-       @comment = @article.comments.create(comment_params)
+     @comment = @article.comments.new(comment_params)

+     unless @comment.valid?
+       @commenter_errors = @comment.errors.full_messages_for(:commenter)
+      @body_errors = @comment.errors.full_messages_for(:body)
+     end

+     if @comment.save
       redirect_to article_path(@article)
+    else
+      render 'articles/show', status: :unprocessable_entity
    end
  end
end

# app/views/articles/show.html.erb

<h1><%= @article.title %></h1>

<p><%= @article.body %></p>

<ul>
  <li><%= link_to "Edit", edit_article_path(@article) %></li>
  <li><%= link_to "Destroy", article_path(@article), data: {
                    turbo_method: :delete,
                    turbo_confirm: "Are you sure?"
                  } %></li>
</ul>

<h2>Add a comment:</h2>
<%= form_with model: [ @article, @article.comments.build ] do |form| %>
  <p>
    <%= form.label :commenter %><br>
    <%= form.text_field :commenter %>
+ <% if @commenter_errors.present? %>
+            <div class="errors">
+           <% @commenter_errors.each do |error| %>
+              <p class="error-message"><%= error %></p>
+         <% end %>
+             </div>
+         <% end %>
  </p>
  <p>
    <%= form.label :body %><br>
    <%= form.text_area :body %>
+ <% if @body_errors.present? %>
+            <div class="errors">
+           <% @body_errors.each do |error| %>
+              <p class="error-message"><%= error %></p>
+         <% end %>
+             </div>
+         <% end %>
  </p>
  <p>
    <%= form.submit %>
  </p>
<% end %>
  1. Elegant way like article does.
# articles_controller.rb
def show
     @article = Article.find(params[:id])
+   @comment = Comment.new(article: @arcticle)
end

# app/views/articles/show.html.erb

<h1><%= @article.title %></h1>

<p><%= @article.body %></p>

<ul>
  <li><%= link_to "Edit", edit_article_path(@article) %></li>
  <li><%= link_to "Destroy", article_path(@article), data: {
                    turbo_method: :delete,
                    turbo_confirm: "Are you sure?"
                  } %></li>
</ul>

<h2>Add a comment:</h2>
<%= form_with model: [ @article, @article.comments.build ] do |form| %>
  <p>
    <%= form.label :commenter %><br>
    <%= form.text_field :commenter %>
+ <% if @comment.errors.any? %>
+         <% @comment.errors.full_messages_for(:commenter).each do |message| %>
+                 <div>
+                     <%= message %>
+                 </div>
+         <% end %>
+  <% end %>
  </p>
  <p>
    <%= form.label :body %><br>
    <%= form.text_area :body %>
+ <% if @comment.errors.any? %>
+         <% @comment.errors.full_messages_for(:body).each do |message| %>
+                 <div>
+                     <%= message %>
+                 </div>
+         <% end %>
+  <% end %>
  </p>
  <p>
    <%= form.submit %>
  </p>
<% end %>

We use @comment = Comment.new(article: @article) instead of @comment = Comment.new in articles_controller.rb because we are going to add comment that associate to an article. I hope it helps anyone who try Ruby on Rails in Ruby on Rails guides.

PS: I just try Ruby and Ruby on Rails around two weeks and I’m still not fluently to use these tools. I’m using GitHub Copilot to assist me to solve this problem.

2 Likes
4

Glad to see someone using Copilot! I am trying to learn rails using codespaces and copilot.

1 Like