Controller works fine locally but not on heroku

Question

I'm using carrierwave with amazon s3 and heroku to upload and store images. It works fine locally but for some reason the controller function "new" isn't being executed on heroku. I've printed the params[:controller] & params[:action] to the view, and both of them are correct, so I'm not sure what the problem is.

Routes.rb

      Rails.application.routes.draw do
  resources :surroundings

  resources :headings

  resources :options

  resources :categories

  resources :mains

  resources :properties do


    resources :images, only: [:index, :new, :create, :destroy] do
    collection do 
    get 'update_main' 
    end

    end


    get 'addoption'
    post 'postoption'

end

root 'search#main'
get 'main' =>'search#main'

images_controller.rb

class ImagesController < ApplicationController




def new
#redirect_to property_images_path #used for trouble shooting - does not redirect
@property=Property.find(params[:property_id])
@image = Image.new

end


 def index
    @images = Property.find(params[:property_id]).images
  end



def update_main
#set the current main image to false
   r=Property.find(params[:property_id]).images.where("main" => true).first
   r.main=false unless r.nil?
   r.save unless r.nil?
   @image=Image.find(params[:main])
   @image.main=true;
   @image.save
 redirect_to property_images_path, notice: "The Image has been uploaded."
end


  def create
    @image = Image.new(image_params)
    @image.property_id=params[:property_id]
    if @image.save
      redirect_to property_images_path, notice: "The Image has been uploaded."
    else
      render "new"
    end
  end

  def destroy
    @image = Image.find(params[:id])
    @image.destroy
    redirect_to property_images_path, notice:  "The Image  has been deleted."
  end

private
  def image_params
   params.require(:image).permit(:attachment,:property_id)
  end
end

new.html.erb

<h1>Add new image</h1>
<%=params[:controller]%>
<%=params[:action]%>


<%= form_for([@property,@image]) do |f| %>
 <%= label_tag("Select image file") %>
   <%= f.file_field :attachment, class:"btn btn-default" %> 

<br>

    <%= f.submit class:"btn btn-primary" %>

<% end %>

heroku error logs

Processing by ImagesController#new as HTML
2016-02-06T07:43:25.314010+00:00 app[web.1]:   Parameters: {"property_id"=>"1"}
2016-02-06T07:43:25.519196+00:00 heroku[router]: at=info method=GET path="/properties/1/images/new" host=auspropguides.herokuapp.com request_id=ecaefc40-5556-4239-9da6-1a154fa489f3 fwd="14.201.25.50" dyno=web.1 connect=0ms service=391ms status=500 bytes=1754
2016-02-06T07:43:25.509640+00:00 app[web.1]:   Rendered images/new.html.erb within layouts/application (1.9ms)
2016-02-06T07:43:25.512962+00:00 app[web.1]: 
2016-02-06T07:43:25.512964+00:00 app[web.1]: ActionView::Template::Error (First argument in form cannot contain nil or be empty):
2016-02-06T07:43:25.509818+00:00 app[web.1]: Completed 500 Internal Server Error in 196ms
2016-02-06T07:43:25.512968+00:00 app[web.1]:     7:  <%= label_tag("Select image file") %>
2016-02-06T07:43:25.512969+00:00 app[web.1]:     8:    <%= f.file_field :attachment, class:"btn btn-default" %> 
2016-02-06T07:43:25.512965+00:00 app[web.1]:     3: <%=params[:action]%>
2016-02-06T07:43:25.512967+00:00 app[web.1]:     5: 
2016-02-06T07:43:25.512968+00:00 app[web.1]:     6: <%= form_for([@property,@image]) do |f| %>
2016-02-06T07:43:25.512966+00:00 app[web.1]:     4: 
2016-02-06T07:43:25.512971+00:00 app[web.1]:   app/views/images/new.html.erb:6:in `_app_views_images_new_html_erb___892626609660663212_69968138740340'
2016-02-06T07:43:25.512972+00:00 app[web.1]: 
2016-02-06T07:43:25.512970+00:00 app[web.1]:     9: 
2016-02-06T07:43:25.512972+00:00 app[web.1]: 

Console log

irb(main):001:0> Property.find(1)
  Property Load (2.2ms)  SELECT  "properties".* FROM "properties" WHERE "properties"."id" = $1 LIMIT 1  [["id", 1]]
  Property Load (2.2ms)  SELECT  "properties".* FROM "properties" WHERE "properties"."id" = $1 LIMIT 1  [["id", 1]]
=> #<Property id: 1, listing_status: "In Draft", my_property_reference: "My reference", floor_area: 350, land_area: 500, state: "New Development", city: "Sydney", area: "CBD", street: "123 fake st", price: 800000, floors: 2, property_type: "Apartment", property_age: nil, completion: 2016, bedrooms: 5, bathrooms: 2, under_cover_car_spaces: 3, car_spaces: nil, car_lock_up_garage: 1, additional_information: "Great location in a great area.", description: "great house great house great house great house gr...", created_at: "2016-02-04 03:44:54", updated_at: "2016-02-04 03:46:55", suburb: nil>
irb(main):002:0> Image.all
  Image Load (1.8ms)  SELECT "images".* FROM "images"
  Image Load (1.8ms)  SELECT "images".* FROM "images"
=> #<ActiveRecord::Relation []>
irb(main):003:0> Image
=> Image(id: integer, main: boolean, attachment: string, created_at: datetime, updated_at: datetime, property_id: integer)
irb(main):004:0> 

Answer 1

The issue is that since you've nested images under properties , you'll have to declare both @instance variables if you want to get the form_for to work:

def new
  @property = Property.find params[:property_id]
  @image    = Image.new
end

Of course, you do this already.

The problem, then, is that your Property with an id of 1 doesn't exist on your Production environment. You need to make sure you're handling your data-set with the same care as you would development (evaluating if dependent objects don't exist):

def new
   @property = Property.find params[:property_id]
   if @property 
      @image = @property.images.new
   else
     redirect_to root_path, notice: "No Property" 
   end
end

---

You'll also want to define multiple resources at once in your routes (to clean it up):

#config/routes.rb
resources :surroundings, :headings, :options, :categories, :mains
resources :properties do
  resources :images, only: [:index, :new, :create, :destroy] do
    get 'update_main', on: :collection
  end
  get  :addoption
  post :postoption
end

resources :search, path: "", only: [] do
  get :main, on: :collection
end

root 'search#main'

---

Update

The solution was trivial, the OP left a photos_controller.rb file with class ImagesController < ApplicationController declaration. Removing this file fixed the issue.