Ruby on Rails not detecting comment field - html

Question

I'm trying to build a very basic Rails app for posting images with a comment. The comment is a required field and the image upload should only go ahead if the comments section has a value, displaying an error message otherwise.
The problem I am having is that even when the comments section is filled in it still displays an error saying that it cannot be blank.
I have tried adding attr_accessor's with the html field names and database values but it makes no difference.
Posts model
class Post < ActiveRecord::Base
has_attached_file :picture, styles: { medium: "300x300>", thumb: "100x100>" }
attr_accessor :picture_file_name
attr_accessor :post_description
validates :description, presence: true
end
Posts controller
class PostsController < ApplicationController
def index
#posts = Post.all
end
def new
#post = Post.new
end
def create
#post = Post.new params[:post].permit(:description, :picture)
if #post.save
redirect_to '/posts'
else
render 'new'
end
end
end
new.html.erb
<% if #post.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#post.errors.count, "error") %> prohibited this post from being saved:</h2>
<ul>
<% #post.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<%= form_for #post, :html => { :multipart => true } do |f| %>
<%= f.label :description %>
<%= f.text_area :description %>
<%= f.label :picture %>
<%= f.file_field :picture %>
<%= f.submit %>
<% end %>
Server readout
=> Booting WEBrick
=> Rails 4.0.4 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2014-04-20 17:59:07] INFO WEBrick 1.3.1
[2014-04-20 17:59:07] INFO ruby 2.1.0 (2013-12-25) [x86_64-darwin12.0]
[2014-04-20 17:59:07] INFO WEBrick::HTTPServer#start: pid=98772 port=3000
Started POST "/posts" for 127.0.0.1 at 2014-04-20 17:59:21 +0100
ActiveRecord::SchemaMigration Load (0.2ms) SELECT "schema_migrations".* FROM "schema_migrations"
Processing by PostsController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"nVrCEAdT+epbltQWR74jtv1weGaq6H7YbWQKFfJNDTw=", "post"=>{"description"=>"test comment", "picture"=>#<ActionDispatch::Http::UploadedFile:0x0000010242f740 #tempfile=#<Tempfile:/var/folders/lm/vrw53rx91831vrh4228m0mfw0000gn/T/RackMultipart20140420-98772-1c9msrz>, #original_filename="dory_2.jpg", #content_type="image/jpeg", #headers="Content-Disposition: form-data; name=\"post[picture]\"; filename=\"dory_2.jpg\"\r\nContent-Type: image/jpeg\r\n">}, "commit"=>"Create Post"}
WARNING: Can't mass-assign protected attributes for Post: description, picture
app/controllers/posts_controller.rb:12:in `create'
(0.1ms) begin transaction
(0.1ms) rollback transaction
Rendered posts/new.html.erb within layouts/application (13.1ms)
Completed 200 OK in 105ms (Views: 65.6ms | ActiveRecord: 0.4ms)

Answer 1

Your params & form look okay
But I would change your strong params to be more conventional:
def create
#post = Post.new(post_params)
#post.save
end
private
def post_params
params.require(:post).permit(:description, :picture)
end

Answer 2

I found the problem.
The issue was that I had originally installed the latest version of Paperclip and then downgraded.
I had added the following gem while I was searching for a solution
gem 'protected_attributes'
This was causing all required fields not to register they were being filled in, such as in user sign up fields etc.
Once that gem was removed it worked just fine.