Blog, w/ Categories using Categorization

categories show.html.erb

<p id="notice"><%= notice %></p>

<p>
  <strong>Name:</strong>
  <%= @category.name %>
  
</p>

<%= link_to 'Edit', edit_category_path(@category) %> |
<%= link_to 'Back', categories_path %>

categorization.rb

class Categorization < ActiveRecord::Base
    belongs_to :post
    belongs_to :category
end

category.rb

class Category < ActiveRecord::Base
    has_many :categorizations
    has_many :posts, :through => :categorizations
end

post.rb

class Post < ActiveRecord::Base
    has_many :categorizations
    has_many :categories, :through => :categorizations
end

posts new.html.erb

<div class="container">
      <br>
      <center>
        <div class="well">
          <div class="row">
            <div class="col-md-12">
              <h1 class="text-center">
                Create a New Blog Post
              </h1>
              <div class="row">
                <div class="col-md-12">
                    <%= form_for :post, url: posts_path do |f| %>

                        <p>
                            <h4><%= f.label :title %></h4>
                            <%= f.text_field :title, :size => "100x1" %><br>
                        </p>
                    
                        <p>
                            <h4><%= f.label :body %></h4>
                            <%= f.text_area :body, :size => "102x10" %><br><br>
                            
                        </p>
                        
                        <div class="row">
                            <div class="col-md-4">
                                <%= f.radio_button("writer", "Anthony") %>
                                <%= f.label "Anthony Joseph" %><br>
                                <%= f.radio_button("writer", "Travis") %>
                                <%= f.label "Travis Mathis" %><br><br>
                            </div>
                            
                            <div class="col-md-4">
                                <h4 class="center-text">
                                    <%= link_to 'Add', '/categories' %> Category
                                </h4>                
                            </div>
                            
                            <%= select_tag(:categories, options_from_collection_for_select(Category.all, :id, :name),:multiple =>true,:size => 8,:class => "text")%>
                            
                            <%= f.submit :Submit, class: "btn btn-success btn-lg" %>
                            
                    <% end %>
                
                </div>
              </div>
            </div>
        </div>
    </div>
</div>