Using Paperclip on a video file in Rails 4 -- strong parameters issue?

Question

I would like to add a video file to an Episode model using Paperclip in a Rails 4.0.0 app. However, I get an error "no implicit conversion of Symbol into Hash" when I call episode_params in my create action (second line):

def create
@episode = Episode.new(episode_params)

respond_to do |format|
  if @episode.save
    format.html { redirect_to @episode, notice: 'Episode was successfully created.' }
    format.json { render action: 'show', status: :created, location: @episode }
  else
    format.html { render action: 'new' }
    format.json { render json: @episode.errors, status: :unprocessable_entity }
  end
end

end

My episode_params method:

def episode_params
  params.require(:episode).permit(:name, :number, :description, :tag_list, :video => [:tempfile, :original_filename, :content_type, :headers])
end

And the params hash:

{"utf8"=>"✓", "authenticity_token"=>"VbOJvzWjlXMHOYpYMkwXUfdUxm9OcQx3LTMIJzk5eJQ=", "episode"=>{"name"=>"Test Episode 2", "number"=>"2", "description"=>"Testing Paperclip with video files", "tag_list"=>"test, file, video", "video"=>#<ActionDispatch::Http::UploadedFile:0x007fec361a80e0 @tempfile=#<Tempfile:/var/folders/yt/prn3v4gx3_bcrq8kr6wlfjjw0000gn/T/RackMultipart20130817-15917-1gu47ht>, @original_filename="file.mov", @content_type="video/quicktime", @headers="Content-Disposition: form-data; name=\"episode[video]\"; filename=\"file.mov\"\r\nContent-Type: video/quicktime\r\n">}, "commit"=>"Create Episode", "action"=>"create", "controller"=>"episodes"}

I've also tried with just :video instead of :video => [ etc ] with no luck. Any ideas would be greatly appreciated.

Full backtrace:

TypeError - no implicit conversion of Symbol into Hash:
  paperclip (3.5.1) lib/paperclip/attachment.rb:72:in `initialize'
  paperclip (3.5.1) lib/paperclip/has_attached_file.rb:46:in `block in define_instance_getter'
  paperclip (3.5.1) lib/paperclip/has_attached_file.rb:65:in `block in define_setter'
  activerecord (4.0.0) lib/active_record/attribute_assignment.rb:42:in `_assign_attribute'
  activerecord (4.0.0) lib/active_record/attribute_assignment.rb:29:in `block in assign_attributes'
  activerecord (4.0.0) lib/active_record/attribute_assignment.rb:23:in `assign_attributes'
  activerecord (4.0.0) lib/active_record/core.rb:192:in `initialize'
  activerecord (4.0.0) lib/active_record/inheritance.rb:27:in `new'
  app/controllers/episodes_controller.rb:34:in `create'
  actionpack (4.0.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
  actionpack (4.0.0) lib/abstract_controller/base.rb:189:in `process_action'
  actionpack (4.0.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
  actionpack (4.0.0) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
  activesupport (4.0.0) lib/active_support/callbacks.rb:413:in `_run__3623801457634608219__process_action__callbacks'
  activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
  actionpack (4.0.0) lib/abstract_controller/callbacks.rb:17:in `process_action'
  actionpack (4.0.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
  actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
  activesupport (4.0.0) lib/active_support/notifications.rb:159:in `block in instrument'
  activesupport (4.0.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
  activesupport (4.0.0) lib/active_support/notifications.rb:159:in `instrument'
  actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
  actionpack (4.0.0) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
  activerecord (4.0.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
  actionpack (4.0.0) lib/abstract_controller/base.rb:136:in `process'
  actionpack (4.0.0) lib/abstract_controller/rendering.rb:44:in `process'
  actionpack (4.0.0) lib/action_controller/metal.rb:195:in `dispatch'
  actionpack (4.0.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
  actionpack (4.0.0) lib/action_controller/metal.rb:231:in `block in action'
  actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
  actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:48:in `call'
  actionpack (4.0.0) lib/action_dispatch/journey/router.rb:71:in `block in call'
  actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `call'
  actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:655: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 `call'
  rack (1.5.2) lib/rack/etag.rb:23:in `call'
  rack (1.5.2) lib/rack/conditionalget.rb:35:in `call'
  rack (1.5.2) lib/rack/head.rb:11:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/flash.rb:241:in `call'
  rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context'
  rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/cookies.rb:486:in `call'
  activerecord (4.0.0) lib/active_record/query_cache.rb:36:in `call'
  activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
  activerecord (4.0.0) lib/active_record/migration.rb:369:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
  activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__4451766820120855143__call__callbacks'
  activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
  actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/reloader.rb:64:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
  better_errors (0.9.0) lib/better_errors/middleware.rb:84:in `protected_app_call'
  better_errors (0.9.0) lib/better_errors/middleware.rb:79:in `better_errors_call'
  better_errors (0.9.0) lib/better_errors/middleware.rb:56:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  railties (4.0.0) lib/rails/rack/logger.rb:38:in `call_app'
  railties (4.0.0) lib/rails/rack/logger.rb:21:in `block in call'
  activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `block in tagged'
  activesupport (4.0.0) lib/active_support/tagged_logging.rb:25:in `tagged'
  activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `tagged'
  railties (4.0.0) lib/rails/rack/logger.rb:21:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
  rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'
  rack (1.5.2) lib/rack/runtime.rb:17:in `call'
  activesupport (4.0.0) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
  rack (1.5.2) lib/rack/lock.rb:17:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/static.rb:64:in `call'
  railties (4.0.0) lib/rails/engine.rb:511:in `call'
  railties (4.0.0) lib/rails/application.rb:97:in `call'
  rack (1.5.2) lib/rack/lock.rb:17:in `call'
  rack (1.5.2) lib/rack/content_length.rb:14:in `call'
  rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
  /Users/timhusson/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
  /Users/timhusson/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
  /Users/timhusson/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'

Answer 1

As for your strong_params question, you should list only the name of the paperclip attachment. Assuming that your ARec class looks like this...

class Episode
  has_attached_file :video, ... options ...
end

Then your params should look like this...

def episode_params
  params.permit(:episode).permit(:name, :number, :description, :tag_list, :video)
end

You can actually get a sense of this if you look closely at the params hash. The :video item is a single object that has some attributes on it. Rails strong_params only cares that it's a single object and treats it like an integer or string so you only need to permit that attribute. I've got that type of thing working fine in a number of places.

Params are not your problem, however.

If you look at the backtrace, the error is coming from Paperclip::Attachment#initialize. Specifically, the referenced line (#72) says:

options = self.class.default_options.merge(options)

That makes a lot of sense in the context if you think about it. The error is telling you that you cannot covert a Symbol into a Hash. Most likely that means that the above statement is receiving a Symbol in the call to "merge(options)". Ultimately this probably means that your has_attached_file call in the class definition is improperly formatted.