title: Rails 3 "No implicit conversion of Symbol into String" using paperclip
body: <p>I am receiving an error in development that says:</p>
  
  <blockquote>
    <p>TypeError in PinsController (no implicit conversion of Symbol into
    String): app/controllers/pins_controller.rb:55:in <code>pin_params'
    app/controllers/pins_controller.rb:21:in</code>create'</p>
  </blockquote>
  
  <p>Here is the relevant code from the pin_controller.rb file (note the line in question is line 21 &amp; 54 below)</p>
  
  <pre><code>class PinsController &lt; ApplicationController
  before_filter :set_pin, only: [:show, :edit, :update, :destroy]
  before_filter :authenticate_user!, except: [:index, :show]
  before_filter :correct_user, only: [:edit, :update, :destroy]
  
    def index
      @pins = Pin.all
    end
  
    def show
    end
  
    def new
      @pin = current_user.pins.build
    end
  
    def edit
    end
  
    def create
      @pin = current_user.pins.build(pin_params)
        if @pin.save
          redirect_to @pin, notice: 'Pin was successfully created.'
        else
          render action: "new"
        end
    end
  
    def update
        if @pin.update_attributes(pin_params)
          redirect_to @pin, notice: 'Pin was successfully updated.'
        else
          render action: "edit"
        end
    end
  
    def destroy
      @pin.destroy
      redirect_to pins_url
    end
  
  private
      # Use callbacks to share common setup or constraints between actions.
      def set_pin
        @pin = Pin.find(params[:id])
      end
  
      def correct_user
        @pin = current_user.pins.where(id: params[:id]).first
        redirect_to pins_path, notice: "Not authorized to edit this pin" if @pin.nil?
      end
  
      # Never trust parameters from the scary internet, only allow the white list through.
      def pin_params
        params.require(:pin).permit(:description, :image)
      end
  end
  </code></pre>
  
  <p>I receive this error message when i try to upload an image with paperclip</p>
  
  <p>The params for the request can be found below:</p>
  
  <pre><code>{"utf8"=&gt;"✓",
   "authenticity_token"=&gt;"IrpaPeq4QumTqHYJ1Aq5K3ThLtOyxk/wnxAK4aqJ3H4=",
   "pin"=&gt;{"image"=&gt;#&lt;ActionDispatch::Http::UploadedFile:0x007f8c2541bed8 @original_filename="url.jpg",
   @content_type="image/jpeg",
   @headers="Content-Disposition: form-data; name=\"pin[image]\"; filename=\"url.jpg\"\r\nContent-Type: image/jpeg\r\n",
   @tempfile=#&lt;Tempfile:/var/folders/bx/z9z06xz54n168tjyyzfm15580000gp/T/RackMultipart20131113-7536-45bhws&gt;&gt;,
   "description"=&gt;"Meow."},
   "commit"=&gt;"Create Pin"}
  </code></pre>
  
  <p>I have included a stack track below as well for everyones reference:</p>
  
  <pre><code>activesupport (3.2.12) lib/active_support/dependencies.rb:251:in `require'
  activesupport (3.2.12) lib/active_support/dependencies.rb:251:in `block in require'
  activesupport (3.2.12) lib/active_support/dependencies.rb:236:in `load_dependency'
  activesupport (3.2.12) lib/active_support/dependencies.rb:251:in `require'
  app/controllers/pins_controller.rb:55:in `pin_params'
  app/controllers/pins_controller.rb:21:in `create'
  actionpack (3.2.12) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
  actionpack (3.2.12) lib/abstract_controller/base.rb:167:in `process_action'
  actionpack (3.2.12) lib/action_controller/metal/rendering.rb:10:in `process_action'
  actionpack (3.2.12) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
  activesupport (3.2.12) lib/active_support/callbacks.rb:425:in `_run__1990095296606139361__process_action__4259560217300663073__callbacks'
  activesupport (3.2.12) lib/active_support/callbacks.rb:405:in `__run_callback'
  activesupport (3.2.12) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
  activesupport (3.2.12) lib/active_support/callbacks.rb:81:in `run_callbacks'
  actionpack (3.2.12) lib/abstract_controller/callbacks.rb:17:in `process_action'
  actionpack (3.2.12) lib/action_controller/metal/rescue.rb:29:in `process_action'
  actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
  activesupport (3.2.12) lib/active_support/notifications.rb:123:in `block in instrument'
  activesupport (3.2.12) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
  activesupport (3.2.12) lib/active_support/notifications.rb:123:in `instrument'
  actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
  actionpack (3.2.12) lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
  activerecord (3.2.12) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
  actionpack (3.2.12) lib/abstract_controller/base.rb:121:in `process'
  actionpack (3.2.12) lib/abstract_controller/rendering.rb:45:in `process'
  actionpack (3.2.12) lib/action_controller/metal.rb:203:in `dispatch'
  actionpack (3.2.12) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
  actionpack (3.2.12) lib/action_controller/metal.rb:246:in `block in action'
  actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:73:in `call'
  actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
  actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:36:in `call'
  journey (1.0.4) lib/journey/router.rb:68:in `block in call'
  journey (1.0.4) lib/journey/router.rb:56:in `each'
  journey (1.0.4) lib/journey/router.rb:56:in `call'
  actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:601:in `call'
  warden (1.2.3) lib/warden/manager.rb:35:in `block in call'
  warden (1.2.3) lib/warden/manager.rb:34:in `catch'
  warden (1.2.3) lib/warden/manager.rb:34:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
  rack (1.4.5) lib/rack/etag.rb:23:in `call'
  rack (1.4.5) lib/rack/conditionalget.rb:35:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/head.rb:14:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/flash.rb:242:in `call'
  rack (1.4.5) lib/rack/session/abstract/id.rb:210:in `context'
  rack (1.4.5) lib/rack/session/abstract/id.rb:205:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/cookies.rb:341:in `call'
  activerecord (3.2.12) lib/active_record/query_cache.rb:64:in `call'
  activerecord (3.2.12) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
  activesupport (3.2.12) lib/active_support/callbacks.rb:405:in `_run__2870100640610547083__call__2066122351646789695__callbacks'
  activesupport (3.2.12) lib/active_support/callbacks.rb:405:in `__run_callback'
  activesupport (3.2.12) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
  activesupport (3.2.12) lib/active_support/callbacks.rb:81:in `run_callbacks'
  actionpack (3.2.12) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/reloader.rb:65:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
  railties (3.2.12) lib/rails/rack/logger.rb:32:in `call_app'
  railties (3.2.12) lib/rails/rack/logger.rb:16:in `block in call'
  activesupport (3.2.12) lib/active_support/tagged_logging.rb:22:in `tagged'
  railties (3.2.12) lib/rails/rack/logger.rb:16:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/request_id.rb:22:in `call'
  rack (1.4.5) lib/rack/methodoverride.rb:21:in `call'
  rack (1.4.5) lib/rack/runtime.rb:17:in `call'
  activesupport (3.2.12) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
  rack (1.4.5) lib/rack/lock.rb:15:in `call'
  actionpack (3.2.12) lib/action_dispatch/middleware/static.rb:62:in `call'
  railties (3.2.12) lib/rails/engine.rb:479:in `call'
  railties (3.2.12) lib/rails/application.rb:223:in `call'
  rack (1.4.5) lib/rack/content_length.rb:14:in `call'
  railties (3.2.12) lib/rails/rack/log_tailer.rb:17:in `call'
  rack (1.4.5) lib/rack/handler/webrick.rb:59:in `service'
  /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
  /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
  /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
  </code></pre>
  
  <p>Finally the full codebase is available at: <a href="https://github.com/tonytrack/pinteresting" rel="nofollow">https://github.com/tonytrack/pinteresting</a></p>
  
  <p>Any help with this would be hugely appreciated! Thanks in advance</p>