In this article, we will implement the ability for users to create, update, delete, and publish posts.

All Parts:

1.  Create a Blog Application with Ruby on Rails 7. First Part: Create the User Resource 
2.  Create a Blog Application with Ruby on Rails 7. Second Part: Create a Post Model and a Posts Controller
3.  Create a Blog Application with Ruby on Rails 7. Third Part: Implement User Authentication
4.  Create a Blog Application with Ruby on Rails 7. Fourth Part: Performing Operations on the Post Resource
5.  Create a Blog Application with Ruby on Rails 7. Fifth Part: Implement Authorization

First, let’s declare the strong parameters in the private method post_params in the Posts controller:

private
 
  def post_params
    params.require(:post).permit(:title, :content, :status, :user_id)
  end

Next, we’ll add the new method to the controller:

def new
    @post = Post.new
 end

 Also, we’ll create the corresponding view, new.html.erb, in the app/views/posts/ folder.

We’ll create a _form.html.erb partial as well because we want to use the same form in both the new and edit views. Let’s create this file and then put this code inside:

<%= form_with(model: post) do |form| %>
   <% if post.errors.any? %>
     <div style="color: red">
       <h2><%= pluralize(post.errors.count, "error") %> prohibited this post from being saved:</h2>
       <ul>
         <% post.errors.each do |error| %>
           <li><%= error.full_message %></li>
         <% end %>
       </ul>
     </div>
   <% end %>
   <div>
     <%= form.label :title, style: "display: block" %>
     <%= form.text_field :title %>
   </div>
   <div>
     <%= form.label :content, style: "display: block" %>
     <%= form.text_area :content %>
   </div>
   <div>
     <%= form.submit %>
   </div>
 <% end %>

Now, let’s render it in the new.html.erb view. Let’s edit this view as follows:

<p style="color: green"><%= notice %></p>
 <h1>New Post</h1>
 <%= render "form", post: @post %>
 <p>
  <%= link_to "All posts", root_path %>
 </p>

Let’s put a link to this action on the post index view at the bottom:

<p>
   <%= link_to 'Add New Post', new_post_path %>
 </p>

Of course, to be able to create a post, we must define a create method. Here we’ll set the post’s user to the user in the session:

def create
   @post = Post.new(post_params)
   @post.user = current_user
   respond_to do |format|
     if @post.save
       format.html {redirect_to @post, notice: 'Post was successfully created.'}
     else
       format.html { render :new, status: :unprocessable_entity }
     end
   end
 end

Next, we add an edit method to our Posts controller:

def edit
   @post = Post.find(params[:id])
 end

Then we create the edit.html.erb view in the app/views/posts/ directory and edit it like this:

<h1>Editing post</h1>
 <%= render "form", post: @post %>
 <p>
   <%= link_to "All posts", root_path %>
 </p>

Let’s put a link to the edit action in the show.html.erb file, right before the closing </footer> tag:

<p>
   <%= link_to 'Edit', edit_post_path(@post) %>
 </p>

Of course, for this form to work, we must define an update method in the Posts controller:

def update
   @post = Post.find(params[:id])
   respond_to do |format|
     if @post.update(post_params)
       format.html { redirect_to post_url(@post), notice: "Post was successfully updated." }
     else
       format.html { render :edit, status: :unprocessable_entity }
     end
   end
 end

Next, we will implement the ability to delete posts. Let’s define a destroy action in the controller:

def destroy
   @post = Post.find(params[:id])
   @post.destroy
   redirect_to root_path
   flash[:notice] = 'Post was successfully deleted.'
 end

And in the post show view, below the link for editing the post, let’s add a delete button:

<%= button_to "Delete", @post, method: :delete %>

Finally, let’s add a publish method to the controller:

def publish
   @post = Post.find(params[:id])
   @post.published!
   redirect_to post_path(@post)
   flash[:notice] = 'Post was successfully published.'
 end

Then we define a route to the publish action. Let’s open the config/routes.rb file and edit the post resource block like this:

resources :posts do
   member do
     get :publish
   end
 end

Last thing we’ll do is to add a publish button in the post show view below the delete button:

<% if @post.draft? %>
   <%= link_to 'Publish', publish_post_path(@post) %>
 <% end %>