无法构建嵌套的多态关联’。 您是否正在尝试构建多态一对一关联

我有一个类似的情况，我有活动，其中有一个任务有一个任务，建立任务也将构建任务，如下所示：

def new @activity = Activity.new @activity.task = @activity.build_task end 

现在我的条款有许多TermTranslations有许多附件有一个可附加（图像或音频）但行18 @term = Term.new(permitted_params[:term])的admin / term.rb我收到此错误：

无法建立协会“可附加”。 您是否正在尝试构建多态一对一关联。

管理员/ term.rb

 ActiveAdmin.register Term do permit_params :id, :display_name, :slug, term_translations_attributes: [:id, :slug, :title, :definition, :example, :language_id, :term_id, :_destroy, attachments_attributes: [:id, :name, :attachable_type, :attachable_id, :_destroy, attachable_attributes: [:id, :image_file, :audio_file, :_destroy]]] form partial: 'form' controller do def new @term = Term.new @term.term_translations.build.attachments.build end def create @term = Term.new(permitted_params[:term]) @term.term_translations.each do |tt| tt.attachments.each do |a| a.attachable = create_attachable(permitted_params[:term][:term_translations_attributes]) end end if @term.save redirect_to admin_term_path(@term) else render :new end end private def create_attachable(term_translations_params) raise term_translations_params.values[0].inspect attachable = term_translations_params.values[0][:attachments_attributes].values[0][:attachable_type].classify attachable.safe_constantize.new(term_translations_params.values[0][:attachable_attributes]) end end end 

楷模

 class Term < ActiveRecord::Base has_many :term_translations, dependent: :destroy has_many :activities accepts_nested_attributes_for :term_translations, allow_destroy: true end - class TermTranslation < ActiveRecord::Base belongs_to :language belongs_to :term has_many :attachments, dependent: :destroy accepts_nested_attributes_for :attachments, allow_destroy: true attr_accessor :attachable_attributes end - class Attachment < ActiveRecord::Base belongs_to :term_translation belongs_to :attachable, polymorphic: true, dependent: :destroy accepts_nested_attributes_for :attachable, allow_destroy: true end - class Image < ActiveRecord::Base has_attached_file :image_file, path: '/images/:filename' validates_attachment_content_type :image_file, content_type: /\Aimage\/.*\Z/ has_one :attachment, as: :attachable end 

查看

管理员/项/ _form.html.erb：

  ActiveAdmin::FormBuilder, multipart: true do |f| %>         

管理员/ term_translations / _form.html.erb：

         { readonly: true } %>    
      
  $(function () { $('#term_term_translations_attributes_NEW_TERM_TRANSLATION_RECORD_attachments_attributes_NEW_ATTACHMENT_RECORD_attachable_type_input').change(onTypeSelected); function onTypeSelected(e) { if (e.val === 'Image') $('#attachable_partial_container').replaceWith(renderImage()); else if (e.val === 'Audio') $('#attachable_partial_container').replaceWith(renderAudio()); } function renderImage() { return ( "
" + "" + "</div" ); } function renderAudio() { return ( "
" + "" + "</div" ); } });    

管理员/图片/ _form.html.erb：

管理员/音频/ _form.html.erb：

堆栈跟踪

 activerecord (4.2.0) lib/active_record/nested_attributes.rb:400:in `assign_nested_attributes_for_one_to_one_association' activerecord (4.2.0) lib/active_record/nested_attributes.rb:343:in `attachable_attributes=' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `public_send' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `_assign_attribute' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `block in assign_nested_parameter_attributes' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `each' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `assign_nested_parameter_attributes' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:45:in `assign_attributes' activerecord (4.2.0) lib/active_record/core.rb:557:in `init_attributes' activerecord (4.2.0) lib/active_record/core.rb:280:in `initialize' activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new' activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new' activerecord (4.2.0) lib/active_record/reflection.rb:131:in `build_association' activerecord (4.2.0) lib/active_record/associations/association.rb:247:in `build_record' activerecord (4.2.0) lib/active_record/associations/collection_association.rb:136:in `build' activerecord (4.2.0) lib/active_record/nested_attributes.rb:465:in `block in assign_nested_attributes_for_collection_association' activerecord (4.2.0) lib/active_record/nested_attributes.rb:460:in `each' activerecord (4.2.0) lib/active_record/nested_attributes.rb:460:in `assign_nested_attributes_for_collection_association' activerecord (4.2.0) lib/active_record/nested_attributes.rb:343:in `attachments_attributes=' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `public_send' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `_assign_attribute' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `block in assign_nested_parameter_attributes' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `each' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `assign_nested_parameter_attributes' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:45:in `assign_attributes' activerecord (4.2.0) lib/active_record/core.rb:557:in `init_attributes' activerecord (4.2.0) lib/active_record/core.rb:280:in `initialize' activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new' activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new' activerecord (4.2.0) lib/active_record/reflection.rb:131:in `build_association' activerecord (4.2.0) lib/active_record/associations/association.rb:247:in `build_record' activerecord (4.2.0) lib/active_record/associations/collection_association.rb:136:in `build' activerecord (4.2.0) lib/active_record/nested_attributes.rb:465:in `block in assign_nested_attributes_for_collection_association' activerecord (4.2.0) lib/active_record/nested_attributes.rb:460:in `each' activerecord (4.2.0) lib/active_record/nested_attributes.rb:460:in `assign_nested_attributes_for_collection_association' activerecord (4.2.0) lib/active_record/nested_attributes.rb:343:in `term_translations_attributes=' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `public_send' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `_assign_attribute' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `block in assign_nested_parameter_attributes' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `each' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:65:in `assign_nested_parameter_attributes' activerecord (4.2.0) lib/active_record/attribute_assignment.rb:45:in `assign_attributes' activerecord (4.2.0) lib/active_record/core.rb:557:in `init_attributes' activerecord (4.2.0) lib/active_record/core.rb:280:in `initialize' activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new' activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new' app/admin/term.rb:18:in `create' actionpack (4.2.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action' actionpack (4.2.0) lib/abstract_controller/base.rb:198:in `process_action' actionpack (4.2.0) lib/action_controller/metal/rendering.rb:10:in `process_action' actionpack (4.2.0) lib/abstract_controller/callbacks.rb:20:in `block in process_action' activesupport (4.2.0) lib/active_support/callbacks.rb:117:in `call' activesupport (4.2.0) lib/active_support/callbacks.rb:151:in `block in halting_and_conditional' activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting' activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting' activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting' activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting' activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting' activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting' activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `_run_callbacks' activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_process_action_callbacks' activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks' actionpack (4.2.0) lib/abstract_controller/callbacks.rb:19:in `process_action' actionpack (4.2.0) lib/action_controller/metal/rescue.rb:29:in `process_action' actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action' activesupport (4.2.0) lib/active_support/notifications.rb:164:in `block in instrument' activesupport (4.2.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument' activesupport (4.2.0) lib/active_support/notifications.rb:164:in `instrument' actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action' actionpack (4.2.0) lib/action_controller/metal/params_wrapper.rb:250:in `process_action' activerecord (4.2.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action' actionpack (4.2.0) lib/abstract_controller/base.rb:137:in `process' actionview (4.2.0) lib/action_view/rendering.rb:30:in `process' actionpack (4.2.0) lib/action_controller/metal.rb:195:in `dispatch' actionpack (4.2.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch' actionpack (4.2.0) lib/action_controller/metal.rb:236:in `block in action' actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `dispatch' actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:42:in `serve' actionpack (4.2.0) lib/action_dispatch/journey/router.rb:43:in `block in serve' actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `each' actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `serve' actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:802:in `call' warden (1.2.7) lib/warden/manager.rb:36:in `block in call' warden (1.2.7) lib/warden/manager.rb:35:in `catch' warden (1.2.7) lib/warden/manager.rb:35:in `call' rack (1.6.8) lib/rack/etag.rb:24:in `call' rack (1.6.8) lib/rack/conditionalget.rb:38:in `call' rack (1.6.8) lib/rack/head.rb:13:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/flash.rb:260:in `call' rack (1.6.8) lib/rack/session/abstract/id.rb:225:in `context' rack (1.6.8) lib/rack/session/abstract/id.rb:220:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/cookies.rb:560:in `call' activerecord (4.2.0) lib/active_record/query_cache.rb:36:in `call' activerecord (4.2.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:647:in `call' activerecord (4.2.0) lib/active_record/migration.rb:378:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call' activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `_run_callbacks' activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_call_callbacks' activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks' actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/reloader.rb:73:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/remote_ip.rb:78:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call' web-console (2.3.0) lib/web_console/middleware.rb:28:in `block in call' web-console (2.3.0) lib/web_console/middleware.rb:18:in `catch' web-console (2.3.0) lib/web_console/middleware.rb:18:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call' railties (4.2.0) lib/rails/rack/logger.rb:38:in `call_app' railties (4.2.0) lib/rails/rack/logger.rb:20:in `block in call' activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `block in tagged' activesupport (4.2.0) lib/active_support/tagged_logging.rb:26:in `tagged' activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `tagged' railties (4.2.0) lib/rails/rack/logger.rb:20:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/request_id.rb:21:in `call' rack (1.6.8) lib/rack/methodoverride.rb:22:in `call' rack (1.6.8) lib/rack/runtime.rb:18:in `call' activesupport (4.2.0) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call' rack (1.6.8) lib/rack/lock.rb:17:in `call' actionpack (4.2.0) lib/action_dispatch/middleware/static.rb:113:in `call' rack (1.6.8) lib/rack/sendfile.rb:113:in `call' railties (4.2.0) lib/rails/engine.rb:518:in `call' railties (4.2.0) lib/rails/application.rb:164:in `call' rack (1.6.8) lib/rack/lock.rb:17:in `call' rack (1.6.8) lib/rack/content_length.rb:15:in `call' rack (1.6.8) lib/rack/handler/webrick.rb:88:in `service' /Users/lancecoe/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/webrick/httpserver.rb:140:in `service' /Users/lancecoe/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/webrick/httpserver.rb:96:in `run' /Users/lancecoe/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/webrick/server.rb:296:in `block in start_thread' Request Parameters: {"utf8"=>"✓", "authenticity_token"=>"zehGpEWIuaFoAbIcOiDiaRiP7UAZxl999YuF79fPL9yypz55Jvo/QVEi3N6idELDTElORw2OoQMu3+2+CI63Pw==", "term"=>{"display_name"=>"angle", "slug"=>"angle", "term_translations_attributes"=>{"0"=>{"title"=>"angle", "slug"=>"angle", "language_id"=>"1", "attachments_attributes"=>{"0"=>{"name"=>"sss", "attachable_type"=>"Image", "attachable_attributes"=>{"image_file"=>#<ActionDispatch::Http::UploadedFile:0x007feaadf23358 @tempfile=#, @original_filename="Screen Shot 2017-06-19 at 5.06.39 PM.png", @content_type="image/png", @headers="Content-Disposition: form-data; name=\"term[term_translations_attributes][0][attachments_attributes][0][attachable_attributes][image_file]\"; filename=\"Screen Shot 2017-06-19 at 5.06.39 PM.png\"\r\nContent-Type: image/png\r\n">}}}}}}, "commit"=>"Create Term"} 

Answer 1

只需将其添加到Attachment模型中

  def build_attachable(params) self.attachable = attachable_type.constantize.new(params) end