Why is paperclip upload giving Trying to link error?

Question

So I have these files

deal.rb

class Deal < ApplicationRecord
  has_many :images, as: :imageable, dependent: :destroy
  #there is more code after this
end

image.rb

class Image < ApplicationRecord
  belongs_to :imageable, polymorphic: true
  belongs_to :deal
  has_attached_file :attachment, styles:  { thumb: "100x100!", medium: "200x200!" }
  validates_attachment_content_type :attachment, content_type: /\Aimage\/.*\z/
end

deals_controller.rb

module Admins
  class DealsController < BaseController
    before_action :find_deal, only: [:edit, :update, :destroy]

    def index
      @deals = Deal.includes(:images)
    end

    def new
      @deal  = Deal.new
    end

    def edit
    end

    def create
      @deal = Deal.new(deal_params.merge(created_by: current_user.id))
      if @deal.save
        flash[:success] = t('.success')
        redirect_to admins_deals_url
      else
        flash.now[:warning] = t('.failure')
        render :new
      end
    end

   def update
    if @deal.update(deal_params)
      flash[:success] = t('.success')
      redirect_to admins_deals_url
    else
      flash.now[:warning] = @deal.errors[:base].to_sentence
      render :edit
    end
   end

   def destroy
     if @deal.destroy
       flash[:success] = t('.success')
       redirect_to admins_deals_url
     else
       flash.now[:warning] = t('.failure')
       render :index
     end
   end

  private
   def deal_params
     params.require(:deal).permit(:title, :description, :price, :discounted_price, :quantity, :publish_date, images_attributes: [:id, :attachment, :_destroy])
   end

   def find_deal
     @deal = Deal.find_by(id: params[:id])
     unless @deal
       flash[:warning] = t('deals.not_found')
       redirect_to admins_deals_path
     end
   end
 end
end

application_controller.rb

class ApplicationController < ActionController::Base
  helper_method :current_user, :current_cart

  def current_user
    @current_user ||= User.find_by(id: current_user_id)
  end

  def current_user_id
    cookies.signed[:user_id] || session[:user_id]
  end

  def current_cart
    @current_cart ||= (current_user.addressed_cart || current_user.cart) if current_user
  end
end

EDIT: Although I don't think application_controller has anything to do with the error

I am creating a deal with nested image attributes. I am using paperclip to upload the images. But I am getting these errors. I don't have any idea what the errors even mean. Here is an image to show the errors.

Here is the pastebin link errors on terminal on creating deal

Answer 1

This appears to be a validation error. Try this for your validation:

validates_attachment_content_type :attachment, :content_type => /image/ 

Or for other variations you can see Validate Attachment Content Type Paperclip

UPDATE after testing your code seems this was a validation error because Paperclip creates an image but doesn't know about the belongs_to association. You can make it optional because by default rails 5 requires the belongs_to id field.

class Image < ApplicationRecord
  belongs_to :imageable, polymorphic: true
  belongs_to :deal, optional: true
  has_attached_file :attachment, styles:  { thumb: "100x100!", medium: "200x200!" }
  validates_attachment_content_type :attachment, content_type: /\Aimage\/.*\z/
end