Rails: uninitialized constant PostsController::TextPost

In my App, I have different kinds of posts people can make. So I had the idea to incorporate the Single Table Inheritance for this:

class Post < ActiveRecord::Base
  has_many :comments
end

class TextPostValidator < ActiveModel::Validator
  def validate(record)
    if record.title.nil? and record.body.nil?
      record.errors[:base] << "Either title or body is necessary"
    end
  end
end

class TextPost < Post
  validates_with TextPostValidator
end

class ImagePost < Post
  validates :image_url, :presence => true
end

class VideoPost < Post
  validates :video_code, :presence => true
  validates :video_service, :presence => true
end

class LinkPost < Post
  validates :link_url, :presence => true
end

And when I now do this in my PostsController:

def new_text
  @post = TextPost.new
end

def new_image
  @post = 开发者_如何学JAVAImagePost.new
end

def new_video
  @post = VideoPost.new
end

def new_link
  @post = LinkPost.new
end

I get this error:

uninitialized constant PostsController::TextPost

It seems I know not enough about the inner workings of Rails to find out why.

Addition From the rails console:

irb(main):009:0* ActiveRecord::Base.subclasses
=> [Post(id: integer, title: string, body: text, video_service: string, video_code: string, image_url: string, link_url: string, ooc: boolean, nsfw: boolean, allow_comment: boolean, type: string, created_at: datetime, updated_at: datetime),
TextPost(id: integer, title: string, body: text, video_service: string, video_code: string, image_url: string, link_url: string, ooc: boolean, nsfw: boolean, allow_comment: boolean, type: string, created_at: datetime, updated_at: datetime),
ImagePost(id: integer, title: string, body: text, video_service: string, video_code: string, image_url: string, link_url: string, ooc: boolean, nsfw: boolean, allow_comment: boolean, type: string, created_at: datetime, updated_at: datetime),
VideoPost(id: integer, title: string, body: text, video_service: string, video_code: string, image_url: string, link_url: string, ooc: boolean, nsfw: boolean, allow_comment: boolean, type: string, created_at: datetime, updated_at: datetime)
LinkPost(id: integer, title: string, body: text, video_service: string, video_code: string, image_url: string, link_url: string, ooc: boolean, nsfw: boolean, allow_comment: boolean, type: string, created_at: datetime, updated_at: datetime)]

Seems ok.

---

An uninitialized constant error comes under a Routing Error. Try going to your routes.rb file and offering both singular and pluralized resources.

resources :post and resources :posts

---

From : http://www.hackido.com/2009/03/quick-tip-solve-uninitialized-constant.html

"Turns out, among the Major changes that came along with the latest Release of Ruby on Rails, there were a few minor ones too. One of those is that the application controller is no longer called application.rb Now it's referred to as application_controller.rb.

In effect, to solve this problem, just rename the file. Or, as Liam points out in the comments below, run:"

rake rails:update