这个已经解决了！这很困难，因为调试起来并不容易。但是，在注意到我在表单标签中有一个表单标签时，我亲切的“回答者”指出，无论这是否是问题的根本原因，都必须对其进行修复。请记住，我同意他的观点，这nested attributes绝对是继续进行下去的方法，但是由于这是目前的学校项目，因此我选择暂时将内部形式移至外部形式之外以使其完成我所期望的。这涉及更改您在下面看到的一些代码。但是，我不会发布该新代码，因为同样，nested attributes在这种情况下，我同意这样做。当我有时间的时候，这将是我对该项目的下一个目标。
nested attributes
我正在使用Rails 4，并且已经嵌套了如下资源：
resources :data do resources :todo_items end
在datum对象的编辑页面中，我打算让用户能够通过ajax 将todo_items 添加 到datum对象。当您单击“添加待办事项”按钮时，将要求我创建新表单todo_item，并在填写必填字段后，用户可以单击添加，并且我希望发出另一个请求，该请求将显示todo_item为包含复选框的部分，供用户显示其是否完整。新表单显示正常，但是ActionController::UnknownFormat单击添加按钮以显示新创建的时出现错误todo_item。这是我正在使用的代码：
datum
todo_item
ActionController::UnknownFormat
app / views / data / _form.html.erb
... <%= link_to 'Add ToDo', new_datum_todo_item_path(@datum.id), remote: true %> ...
app / controllers / todo_items_controller.rb
class TodoItemsController < ApplicationController def new @datum = Datum.find(params[:datum_id]) @todo = TodoItem.new respond_to do |format| format.js end end def create @datum = Datum.find(params[:datum_id]) @todo = @datum.todo_items.create!(todo_item_params) respond_to do |format| format.js end end private def todo_item_params params.require(:todo_item).permit(:task, :content, :done) end end
app / views / todo_items / _form.html.erb（“新”表单）
<div id="<%= datum.id %>-<%= todo.id %>" class="panel todo-item"> <%= bootstrap_form_for([datum, todo], remote: true) do |f| %> <%= render 'shared/error_messages', object: f.object %> <%= f.hidden_field :done, value: false %> <%= f.text_field :task, hide_label: true, placeholder: 'task' %> <%= f.text_area :content, hide_label: true, placeholder: 'content' %> <%= f.submit 'Add', class: 'btn btn-primary btn-sm' %> <% end %> </div>
app / views / todo_items / _todo.html.erb
<%= bootstrap_form_for([datum, todo], remote: true) do |f| %> <%= render 'shared/error_messages', object: f.object %> <%= f.check_box :done, hide_label: true %> <div><%= todo.task %></div> <div><%= todo.content %></div> <% end %>
app / views / todo_items / new.js.erb（有效的响应）
$('.panel-body').append("<%= escape_javascript(render partial: 'form', locals: { datum: @datum, todo: @todo }) %>");
app / views / todo_items / create.js.erb（无效的响应）
$("#<%= @datum.id %>-<%= @todo.id %>").html("<%= escape_javascript(render partial: 'todo_items/todo', locals: { datum: @datum, todo: @todo }) %>");
有人可以帮我弄清楚我在做什么错吗？我只打算respond_to format.js。两种形式都包括remote: true。我觉得我在这里错过了一些非常愚蠢的东西，但是很长一段时间以来我一直在试图弄清这一点。谢谢！如果需要提供更多信息，请告诉我…
respond_to
format.js
remote: true
这是在服务器日志中出现的带有new和create请求的内容：
Started GET "/data/532799016a616b1786040000/todo_items/new" for 127.0.0.1 at 2014-03-20 16:05:04 -0600 Processing by TodoItemsController#new as JS Parameters: {"datum_id"=>"532799016a616b1786040000"} MOPED: 127.0.0.1:27017 COMMAND database=admin command={:ismaster=>1} runtime: 0.4793ms MOPED: 127.0.0.1:27017 QUERY database=datums_app_development collection=data selector={"_id"=>BSON::ObjectId('532799016a616b1786040000')} flags=[] limit=0 skip=0 batch_size=nil fields=nil runtime: 0.4106ms Rendered shared/_error_messages.html.erb (0.6ms) Rendered todo_items/_form.html.erb (8.8ms) Rendered todo_items/new.js.erb (14.3ms) Completed 200 OK in 39ms (Views: 15.8ms | ActiveRecord: 0.0ms) Started POST "/data/532799016a616b1786040000/todo_items" for 127.0.0.1 at 2014-03-20 16:05:11 -0600 Processing by TodoItemsController#create as HTML Parameters: {"utf8"=>"✓", "authenticity_token"=>"stsyxQfAuzPa1BGnOx2cAuagZqFuSHF6jfos9/euw94=", "todo_item"=>{"done"=>"false", "task"=>"Task", "content"=>"Content"}, "commit"=>"Add", "datum_id"=>"532799016a616b1786040000"} MOPED: 127.0.0.1:27017 QUERY database=datums_app_development collection=data selector={"_id"=>BSON::ObjectId('532799016a616b1786040000')} flags=[] limit=0 skip=0 batch_size=nil fields=nil runtime: 0.5380ms MOPED: 127.0.0.1:27017 UPDATE database=datums_app_development collection=data selector={"_id"=>BSON::ObjectId('532799016a616b1786040000')} update={"$push"=>{"todo_items"=>{"_id"=>BSON::ObjectId('532b66176a616b4160010000'), "task"=>"Task", "content"=>"Content", "done"=>false, "updated_at"=>2014-03-20 22:05:11 UTC, "created_at"=>2014-03-20 22:05:11 UTC}}} flags=[] COMMAND database=datums_app_development command={:getlasterror=>1, :w=>1} runtime: 1.1161ms Completed 406 Not Acceptable in 8ms ActionController::UnknownFormat - ActionController::UnknownFormat: actionpack (4.0.2) lib/action_controller/metal/mime_responds.rb:372:in `retrieve_collector_from_mimes' actionpack (4.0.2) lib/action_controller/metal/mime_responds.rb:189:in `respond_to' app/controllers/todo_items_controller.rb:13:in `create' actionpack (4.0.2) lib/action_controller/metal/implicit_render.rb:4:in `send_action' actionpack (4.0.2) lib/abstract_controller/base.rb:189:in `process_action' actionpack (4.0.2) lib/action_controller/metal/rendering.rb:10:in `process_action' actionpack (4.0.2) lib/abstract_controller/callbacks.rb:18:in `block in process_action' activesupport (4.0.2) lib/active_support/callbacks.rb:403:in `_run__1881092772621756057__process_action__callbacks' activesupport (4.0.2) lib/active_support/callbacks.rb:80:in `run_callbacks' actionpack (4.0.2) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (4.0.2) lib/action_controller/metal/rescue.rb:29:in `process_action' actionpack (4.0.2) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action' activesupport (4.0.2) lib/active_support/notifications.rb:159:in `block in instrument' activesupport (4.0.2) lib/active_support/notifications/instrumenter.rb:20:in `instrument' activesupport (4.0.2) lib/active_support/notifications.rb:159:in `instrument' actionpack (4.0.2) lib/action_controller/metal/instrumentation.rb:30:in `process_action' actionpack (4.0.2) lib/action_controller/metal/params_wrapper.rb:245:in `process_action' activerecord (4.0.2) lib/active_record/railties/controller_runtime.rb:18:in `process_action' actionpack (4.0.2) lib/abstract_controller/base.rb:136:in `process' actionpack (4.0.2) lib/abstract_controller/rendering.rb:44:in `process' actionpack (4.0.2) lib/action_controller/metal.rb:195:in `dispatch' actionpack (4.0.2) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch' actionpack (4.0.2) lib/action_controller/metal.rb:231:in `block in action' actionpack (4.0.2) lib/action_dispatch/routing/route_set.rb:80:in `dispatch' actionpack (4.0.2) lib/action_dispatch/routing/route_set.rb:48:in `call' actionpack (4.0.2) lib/action_dispatch/journey/router.rb:71:in `block in call' actionpack (4.0.2) lib/action_dispatch/journey/router.rb:59:in `call' actionpack (4.0.2) lib/action_dispatch/routing/route_set.rb:680: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 (4.0.2) lib/action_dispatch/middleware/params_parser.rb:27:in `call' actionpack (4.0.2) 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 (4.0.2) lib/action_dispatch/middleware/cookies.rb:486:in `call' activerecord (4.0.2) lib/active_record/query_cache.rb:36:in `call' activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call' activerecord (4.0.2) lib/active_record/migration.rb:369:in `call' actionpack (4.0.2) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call' activesupport (4.0.2) lib/active_support/callbacks.rb:373:in `_run__936815074203488114__call__callbacks' activesupport (4.0.2) lib/active_support/callbacks.rb:80:in `run_callbacks' actionpack (4.0.2) lib/action_dispatch/middleware/callbacks.rb:27:in `call' actionpack (4.0.2) lib/action_dispatch/middleware/reloader.rb:64:in `call' actionpack (4.0.2) lib/action_dispatch/middleware/remote_ip.rb:76:in `call' better_errors (1.0.1) lib/better_errors/middleware.rb:84:in `protected_app_call' better_errors (1.0.1) lib/better_errors/middleware.rb:79:in `better_errors_call' better_errors (1.0.1) lib/better_errors/middleware.rb:56:in `call' actionpack (4.0.2) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call' actionpack (4.0.2) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call' railties (4.0.2) lib/rails/rack/logger.rb:38:in `call_app' railties (4.0.2) lib/rails/rack/logger.rb:20:in `block in call' activesupport (4.0.2) lib/active_support/tagged_logging.rb:67:in `block in tagged' activesupport (4.0.2) lib/active_support/tagged_logging.rb:25:in `tagged' activesupport (4.0.2) lib/active_support/tagged_logging.rb:67:in `tagged' railties (4.0.2) lib/rails/rack/logger.rb:20:in `call' actionpack (4.0.2) 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 (4.0.2) lib/active_support/cache/strategy/local_cache.rb:83:in `call' rack (1.5.2) lib/rack/lock.rb:17:in `call' actionpack (4.0.2) lib/action_dispatch/middleware/static.rb:64:in `call' rack (1.5.2) lib/rack/sendfile.rb:112:in `call' railties (4.0.2) lib/rails/engine.rb:511:in `call' railties (4.0.2) 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' /home/jake/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service' /home/jake/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run' /home/jake/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
一种可能的错误与dom对象选择器有关。尝试：
$('#<%= @datum.id %>-<%= @todo.id %>').html("<%= escape_javascript(render partial: 'todo_items/todo', locals: { datum: @datum, todo: @todo }) %>");
使用jqueryby #id而不是by 选择器.class。由于您已将实例信息（id="<%= datum.id %>-<%= todo.id %>"）添加到id属性：
jquery
#id
.class
id="<%= datum.id %>-<%= todo.id %>"
id
<div id="<%= datum.id %>-<%= todo.id %>" class="panel todo-item">
评论后链接评论源代码后更新
您使用的是form内部form，这是不正确的，浏览器 不支持 它，并且可能会导致不可预测的行为，例如您的情况。
form
您应该改变您的方法/实现。在这种情况下，您可能需要使用accepts_nested_attributes_for和fields_for。
accepts_nested_attributes_for
fields_for
这里是相关的RailsCast。
