Ruby-on-rails 出现无法自动加载常量 UsersController 的错误

getting error as Unable to autoload constant UsersController

提问by Preethika

I am getting an error while visiting /users/newin Rails 4 as Unable to autoload constant UsersController, expecting /app/controllers/users_controller.rb to define it.

而来访的，我得到一个错误/users/new的轨道4作为Unable to autoload constant UsersController, expecting /app/controllers/users_controller.rb to define it。

Here is the controller code

这是控制器代码

    class UserController < ApplicationController
     def new
      @user = User.new
     end

     def create
      @user = User.new(params[:user]).permit(:email,  :password,:password_confirmation)

      respond_to do |format|
       if @user.save
        format.html { redirect_to new_user_path, notice: 'User was successfully created.' }
        format.json { render action: 'show', status: :created, location: @user }
       else
        format.html { render action: 'new' }
        format.json { render json: @user.errors, status: :unprocessable_entity }
       end
      end
    end 
  end

And the view for new.html.erbI have is:

我的观点new.html.erb是：

  <h1>Sign up</h1>

  <%= form_for(@user)  do |f| %>

    <% if @user.errors.any? %>
      <div id="error_explanation">
        <h2><%= pluralize(@user.errors.count, "error") %> prohibited this post from being      saved:</h2>

        <ul>
          <% @user.errors.full_messages.each do |msg| %>
            <li><%= msg %></li>
          <% end %>
        </ul>
     </div>
   <% end %>
   <div class="field">
    <%= f.label :email %><br>
    <%= f.text_field :email %>
   </div>
   <div class="field">
    <%= f.label :password %><br>
    <%= f.password_field :password %>
   </div>
   <div class="field">
    <%= f.label :password_confirmation, "Confirmation" %>
    <%= f.password_field :password_confirmation %>
   </div>
   <div class="actions">
    <%= f.submit "Create my account" %>
   </div>
 <% end %>

Usermodel:

User模型：

class User < ActiveRecord::Base
  has_many :projects
  has_many :pledges
  has_many :posts
  has_many :comments
end

回答by sealocal

Rails expects controller names to be pluralized. The very first line of the the first file contents you posted is written as singular:

Rails 期望控制器名称为复数形式。您发布的第一个文件内容的第一行写为单数：

In /app/controllers/users_controller.rbyou have:

在/app/controllers/users_controller.rb你有：

class UserController < ApplicationController

类用户控制器 < 应用控制器

Instead, it should be:

相反，它应该是：

class UsersController < ApplicationController

类用户控制器 < 应用控制器

This Rails Guideprovides an example for defining a resource in your routes file. Further, there is an informational note that explains that defining a routes with the resourcemethod will always map to the pluralized name of the controller.

本Rails 指南提供了一个在路由文件中定义资源的示例。此外，有一条信息说明解释了使用该resource方法定义路由将始终映射到控制器的复数名称。

This is the informational note from the guide.

这是指南中的信息说明。

Because you might want to use the same controller for a singular route (/account) and a plural route (/accounts/45), singular resources map to plural controllers. So that, for example, resource :photo and resources :photos creates both singular and plural routes that map to the same controller (PhotosController).

因为您可能希望对单数路由 (/account) 和复数路由 (/accounts/45) 使用相同的控制器，所以单一资源映射到多个控制器。因此，例如，资源 :photo 和资源 :photos 创建映射到同一控制器 (PhotosController) 的单数和复数路由。

source: Resource Routing: The Rails Default

来源：资源路由：Rails 默认