Ruby on Rails формы вспомогательные проблемы

Question

У меня сложный сценарий, который мне нужно реализовать и не могу понять, как это сделать. Я пытаюсь создать форму, которая передает свои данные в хеше с надписью «сообщение» контроллеру, который затем создаст объект сообщения, но я не могу использовать form_for, потому что мне нужно использовать тег hidden_field, а не hidden_field.

Вот форма у меня до сих пор:

=form_tag(:action => 'create', :controller => 'messages', :method => :get) do 
     =text_area :message, :message, :size => '40x5' 
     =hidden_field_tag(:message, :subject => "RE:#{@message.subject}") 
     =hidden_field_tag(:message, :parent => @message.id) 
     =hidden_field_tag(:message, :receiver => @message.sender) 
     =submit_tag 'Reply' 

Я хочу, чтобы контроллер получить:

{"message"=>"{:message=>"How are you?", :subject=>"Hi", :parent=>nil, :receiver=>2}", "commit"=>"Reply", "method"=>"get", "action"=>"create", "controller"=>"messages"} 

однако, я получаю:

{"message"=>"{:receiver=>2}", "commit"=>"Reply", "method"=>"get", "action"=>"create", "controller"=>"messages"} 

и тому значение текстовой области получает значение сообщения, на которое я отвечаю. Может ли кто-нибудь мне помочь?

Edit: После реализации ответ Рассела, я теперь получить:

Message(#39922460) expected, got String(#15633780) 

Вот полный след:

activerecord (3.2.13) lib/active_record/associations/association.rb:204:in `raise_on_type_mismatch' 
activerecord (3.2.13) lib/active_record/associations/belongs_to_association.rb:6:in `replace' 
activerecord (3.2.13) lib/active_record/associations/singular_association.rb:17:in `writer' 
activerecord (3.2.13) lib/active_record/associations/builder/association.rb:51:in `block in define_writers' 
activerecord (3.2.13) lib/active_record/attribute_assignment.rb:85:in `block in assign_attributes' 
activerecord (3.2.13) lib/active_record/attribute_assignment.rb:78:in `each' 
activerecord (3.2.13) lib/active_record/attribute_assignment.rb:78:in `assign_attributes' 
activerecord (3.2.13) lib/active_record/base.rb:498:in `initialize' 
activerecord (3.2.13) lib/active_record/validations.rb:39:in `new' 
activerecord (3.2.13) lib/active_record/validations.rb:39:in `create!' 
app/controllers/messages_controller.rb:13:in `create' 
actionpack (3.2.13) lib/action_controller/metal/implicit_render.rb:4:in `send_action' 
actionpack (3.2.13) lib/abstract_controller/base.rb:167:in `process_action' 
actionpack (3.2.13) lib/action_controller/metal/rendering.rb:10:in `process_action' 
actionpack (3.2.13) lib/abstract_controller/callbacks.rb:18:in `block in process_action' 
activesupport (3.2.13) lib/active_support/callbacks.rb:425:in `_run__3805623263237724248__process_action__1465637019578896381__callbacks' 
activesupport (3.2.13) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.13) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks' 
activesupport (3.2.13) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.13) lib/abstract_controller/callbacks.rb:17:in `process_action' 
actionpack (3.2.13) lib/action_controller/metal/rescue.rb:29:in `process_action' 
actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' 
activesupport (3.2.13) lib/active_support/notifications.rb:123:in `block in instrument' 
activesupport (3.2.13) lib/active_support/notifications/instrumenter.rb:20:in `instrument' 
activesupport (3.2.13) lib/active_support/notifications.rb:123:in `instrument' 
actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:29:in `process_action' 
actionpack (3.2.13) lib/action_controller/metal/params_wrapper.rb:207:in `process_action' 
activerecord (3.2.13) lib/active_record/railties/controller_runtime.rb:18:in `process_action' 
actionpack (3.2.13) lib/abstract_controller/base.rb:121:in `process' 
actionpack (3.2.13) lib/abstract_controller/rendering.rb:45:in `process' 
actionpack (3.2.13) lib/action_controller/metal.rb:203:in `dispatch' 
actionpack (3.2.13) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' 
actionpack (3.2.13) lib/action_controller/metal.rb:246:in `block in action' 
actionpack (3.2.13) lib/action_dispatch/routing/route_set.rb:73:in `call' 
actionpack (3.2.13) lib/action_dispatch/routing/route_set.rb:73:in `dispatch' 
actionpack (3.2.13) 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 (3.2.13) lib/action_dispatch/routing/route_set.rb:612:in `call' 
actionpack (3.2.13) 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 (3.2.13) lib/action_dispatch/middleware/head.rb:14:in `call' 
actionpack (3.2.13) lib/action_dispatch/middleware/params_parser.rb:21:in `call' 
actionpack (3.2.13) 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 (3.2.13) lib/action_dispatch/middleware/cookies.rb:341:in `call' 
activerecord (3.2.13) lib/active_record/query_cache.rb:64:in `call' 
activerecord (3.2.13) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call' 
actionpack (3.2.13) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call' 
activesupport (3.2.13) lib/active_support/callbacks.rb:405:in `_run__3699448979629391707__call__1119864259513439622__callbacks' 
activesupport (3.2.13) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.13) lib/active_support/callbacks.rb:385:in `_run_call_callbacks' 
activesupport (3.2.13) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.13) lib/action_dispatch/middleware/callbacks.rb:27:in `call' 
actionpack (3.2.13) lib/action_dispatch/middleware/reloader.rb:65:in `call' 
actionpack (3.2.13) lib/action_dispatch/middleware/remote_ip.rb:31:in `call' 
actionpack (3.2.13) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call' 
actionpack (3.2.13) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call' 
railties (3.2.13) lib/rails/rack/logger.rb:32:in `call_app' 
railties (3.2.13) lib/rails/rack/logger.rb:16:in `block in call' 
activesupport (3.2.13) lib/active_support/tagged_logging.rb:22:in `tagged' 
railties (3.2.13) lib/rails/rack/logger.rb:16:in `call' 
actionpack (3.2.13) 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 (3.2.13) lib/active_support/cache/strategy/local_cache.rb:72:in `call' 
rack (1.4.5) lib/rack/lock.rb:15:in `call' 
actionpack (3.2.13) lib/action_dispatch/middleware/static.rb:63:in `call' 
railties (3.2.13) lib/rails/engine.rb:479:in `call' 
railties (3.2.13) lib/rails/application.rb:223:in `call' 
rack (1.4.5) lib/rack/content_length.rb:14:in `call' 
railties (3.2.13) lib/rails/rack/log_tailer.rb:17:in `call' 
rack (1.4.5) lib/rack/handler/webrick.rb:59:in `service' 
/home/renee/.rvm/rubies/ruby-1.9.3-p374/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service' 
/home/renee/.rvm/rubies/ruby-1.9.3-p374/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run' 
/home/renee/.rvm/rubies/ruby-1.9.3-p374/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread' 

Answer 1

Я думаю, что вы, вероятно, хотите что-то ближе к этому (не проверено):

=form_tag(:action => 'create', :controller => 'messages', :method => :get) do 
    =text_area "message[message]", :size => '40x5' 
    =hidden_field_tag("message[subject]", "RE:#{@message.subject}") 
    =hidden_field_tag("message[parent]", @message.id) 
    =hidden_field_tag("message[receiver]", @message.sender) 
    =submit_tag 'Reply'