Ruby on rails 无法使用Rails创建MongoDB文档

我在使用MongoDB和Rails时遇到了很多问题。我正在尝试创建用户提要，但当我试图保存文档时，Rails一直在侮辱我。我只是不知道发生了什么，而且据我所知，这些文档似乎没有什么帮助，我已经按书做了所有的事情

以下是我所做的关系：

class Feed
  include Mongoid::Document
  field       :name,        :type => String
  field       :description, :type => String
  has_many    :feedposts
  embedded_in :user
end

class Feedpost
  include Mongoid::Document
  field :title    => String
  field :text     => String
  field :resource => String
  field :time     => Time, :default => -> { Time.now }
  belongs_to  :feed
  embeds_many :comments
end

class Comment
  include Mongoid::Document
  has_one :user
  field   :text => String
  field   :time => Time, :default => -> { Time.now }
  embedded_in :feedpost
end

当试图保存一个Feed时，没有提示Feedpost或评论，它只是告诉我新的方法？未为类定义。 我从Rails得到了这个回溯：

activesupport (3.1.0.rc5) lib/active_support/whiny_nil.rb:48:in `method_missing'
mongoid (2.2.0) lib/mongoid/persistence/operations/embedded/insert.rb:31:in `block in persist'
mongoid (2.2.0) lib/mongoid/persistence/insertion.rb:26:in `block (3 levels) in prepare'
activesupport (3.1.0.rc5) lib/active_support/callbacks.rb:390:in `_run_create_callbacks'
activesupport (3.1.0.rc5) lib/active_support/callbacks.rb:81:in `run_callbacks'
mongoid (2.2.0) lib/mongoid/persistence/insertion.rb:25:in `block (2 levels) in prepare'
activesupport (3.1.0.rc5) lib/active_support/callbacks.rb:390:in `_run_save_callbacks'
activesupport (3.1.0.rc5) lib/active_support/callbacks.rb:81:in `run_callbacks'
mongoid (2.2.0) lib/mongoid/persistence/insertion.rb:24:in `block in prepare'
mongoid (2.2.0) lib/mongoid/persistence/insertion.rb:22:in `tap'
mongoid (2.2.0) lib/mongoid/persistence/insertion.rb:22:in `prepare'
mongoid (2.2.0) lib/mongoid/persistence/operations/embedded/insert.rb:30:in `persist'
mongoid (2.2.0) lib/mongoid/persistence.rb:44:in `insert'
mongoid (2.2.0) lib/mongoid/persistence.rb:149:in `upsert'

编辑： 这是控制器：

class FeedsController < ApplicationController
  def index
    @user  = CurrentUser()
    @feeds = @user.feeds
  end

  def create
    @feed   = Feed.new params[:feed]
    success = @feed.save # This is the line that trigger the error
    render json: { :success => success }
  end
end

---

我到底怎么了？有人有想法吗？

您可能需要发布更多关于mongodb设置的信息。你能在里面存储任何东西吗？正如mkro提到的，我们需要看到你的控制器代码，只是为了在这里插话。我认为这不是完整的回溯，因为它是从activesupport中的代码开始的。你能发布整个跟踪吗？是哪一行触发了错误？回溯中缺少的那一行是异常NoMethodError的本质，它是nil:NilClass的未定义方法“new”，由注释为的控制器行触发。谢谢你的帮助，我想我已经达到了要求：！请将您发送给控制器的参数发布。

development:
  host: localhost
  database: noosphere_development