Implement Carrierwave_direct in Wicked Wizard Rails 4.2 - ruby-on-rails

Question

I have an app set up with a Wicked Wizard form to create a new post.
The last step allows users to upload pictures to their post.
For image processing I am using Carrierwave and Fog (because I'm hosting the site on heroku and I am using Amazon S3 for storage).
It's all working fine, but the upload to Amazon S3 is very slow.
Following Ryan Bates' Uploading to Amazon S3 railscast (http://railscasts.com/episodes/383-uploading-to-amazon-s3) I tried Carrierwave_Direct (https://github.com/dwilkie/carrierwave_direct) to speed up the painfully slow upload to Amazon S3.
When doing this, however, I get an error:
NoMethodError in PostSteps#show
Showing
/Users/petersonneveld/rails_projects/doamer/doamer2/app/views/property_steps/picture.html.erb where line #1 raised:
undefined method `direct_fog_url' for nil:NilClass
I really don't know what to do to solve this. Does anyone have advice? Thanks a bunch for your help!
In the last step of my wicked wizard form I have
# app/views/post_steps/picture.html.erb
<%= direct_upload_form_for #uploader, url: wizard_path do |f| %>
<div class="panel panel-default">
<div class="panel-heading">
<div class="panel-title">
<h2>Let's post some pictures!</h2>
</div>
</div>
<div class="panel-body">
<% 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 |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="form-group col-md-12">
<%= f.label :image, "Upload image" %><br>
<%= image_tag(#post.image_url(:thumb)).to_s if #post.image? %>
<%= f.file_field :image %>
</div>
<div class="form-group col-md-12">
<%= f.label :remote_image_url, "or paste image URL" %>
<%= f.text_field :remote_image_url, class: "form-control" %>
<%= f.hidden_field :image_cache %>
</div>
<div class="form-group col-md-12">
<h4><%= f.check_box :remove_image %>
<span class="label label-danger">Remove image</span></h4>
</div>
<div class="form-group col-md-12">
<%= f.button "Finish", class: "btn btn-primary", data: {disable_with: "<i class='fa fa-spinner fa-spin'></i> Saving post..."} %>
</div>
</div>
</div>
<% end %>
And in my controller
# app/controllers/post_steps_controller.rb
class PostStepsController < ApplicationController
include Wicked::Wizard
steps :description, :picture
def show
#post = Post.find(params[:post_id])
render_wizard
end
def update
#post = Post.find(params[:post_id])
#post.update_attributes(post_params)
render_wizard #post
end
private
def post_params
params.require(:post).permit(...)
end
def redirect_to_finish_wizard(options = nil)
redirect_to #post, notice: "Thanks for submitting a post."
end
end
And my post controller create action
# app/controllers/post_controller.rb
def create
#post = current_user.posts.build(post_params)
if #post.save
redirect_to post_steps_path(:id => "description", :post_id => #post.id)
else
render :new
end
end

Answer 1

Found the answer: had to update the 'aws-sdk' gem!