ActionController::ParameterMissing 使用自定义路线

Question

我正在构建一个数字图书馆，目前我正在尝试将 soft_delete 添加到应用程序，但我遇到了显示

错误的问题

ActionController::ParameterMissing in BooksController#update
param is missing or the value is empty: book

soft_delete 方法的作用是将其在数据库中的 table 从默认的 false 值更新为 true。我检查了我的代码，但找不到问题出在哪里。

图书模型

class Book < ApplicationRecord
  #add a model scope to fetch only non-deleted records
  scope :not_deleted, -> { where(soft_deleted: false) }
  scope :deleted, -> { where(soft_deleted: true) }

  #create the soft delete method
  def soft_delete 
    update(soft_deleted: true)
    soft_deleted
  end

  # make an undelete method
  def undelete
    update(soft_deleted: false)
  end
end

书籍控制器（截断）

class BooksController < ApplicationController
  before_action :set_book, only: [:show, :edit, :update, :soft_delete, :destroy]

  def index
    @books = Book.not_deleted
  end

...

  def destroy
    @book.destroy
    respond_to do |format|
      format.html { redirect_to books_url, notice: 'Book was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  def soft_delete
    respond_to do |format|
      @book.soft_delete(book_params)
        format.html { redirect_to books_url, notice: 'Book was successfully deleted.' }
        format.json { head :no_content }
    end
  end



  private
    # Use callbacks to share common setup or constraints between actions.
    def set_book
      @book = Book.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def book_params
      params.require(:book).permit(:name, :author, :description, :soft_deleted)
    end
end

路线

Rails.application.routes.draw do
  resources :books
  put '/books/:id' => 'books#soft_delete'
end

图书索引视图

<h1>Books</h1>
<tbody>
    <% @books.each do |book| %>
      <tr>
        <td><%= book.name %></td>
        <td><%= book.author %></td>
        <td><%= book.description %></td>
        <td><%= link_to 'Show', book %></td>
        <td><%= link_to 'Edit', edit_book_path(book) %></td>
        <td><%= link_to 'Destroy', book, method: :delete, data: { confirm: 'Are you sure?' } %></td>
        <td><%= link_to 'Soft Delete', book, method: :put, data: { confirm: 'Are you sure?' } %></td>
        soft_delete
      </tr>
    <% end %>
  </tbody>

Answer 1

Rails 将 <%= link_to 'Soft Delete', book, method: :put...%> 路由到 update 操作，因为 resource :books 是在您的自定义路由之前定义的，并且 Rails 使用与请求。

运行 rails routes -g books 在终端中，你会看到如下内容：

    books GET    /books(.:format)          books#index
          POST   /books(.:format)          books#create
 new_book GET    /books/new(.:format)      books#new
edit_book GET    /books/:id/edit(.:format) books#edit
     book GET    /books/:id(.:format)      books#show
          PATCH  /books/:id(.:format)      books#update
          PUT    /books/:id(.:format)      books#update
          DELETE /books/:id(.:format)      books#destroy
          PUT    /books/:id(.:format)      books#soft_delete

如您所见，books#update 和 books#soft_delete 的路由相同。

您可以通过创建命名路由来修复它：put '/books/:id' => 'books#soft_delete', as: 'soft_delete':

      books GET    /books(.:format)          books#index
            POST   /books(.:format)          books#create
   new_book GET    /books/new(.:format)      books#new
  edit_book GET    /books/:id/edit(.:format) books#edit
       book GET    /books/:id(.:format)      books#show
            PATCH  /books/:id(.:format)      books#update
            PUT    /books/:id(.:format)      books#update
            DELETE /books/:id(.:format)      books#destroy
soft_delete PUT    /books/:id(.:format)      books#soft_delete

然后，修改您的模板以使用新的助手：<%= link_to 'Soft Delete', soft_delete_path(book), method: :put...%>

Answer 2

我建议你不要使用像 put '/books/:id' => 'books#soft_delete' Rails 有 'member routes'，所以你可以这样重写你的路线：

resources :books, only: %i[index destroy] do
  member { put :soft_delete }
end

我在这里使用了选项 'only'，它允许您只为您定义必要的路线（不是全部 7 条，而是 2 条 - 索引和销毁）

首先：您已经定义了 resources :books。此定义为您创建了 7 条路线：

    books GET    /books(.:format)           -> books#index
          POST   /books(.:format)           -> books#create
 new_book GET    /books/new(.:format)       -> books#new
edit_book GET    /books/:id/edit(.:format)  -> books#edit
     book GET    /books/:id(.:format)       -> books#show
          PATCH  /books/:id(.:format)       -> books#update (this and next route are the same, and considering as 1, so we have 7 routes, not 8)
          PUT    /books/:id(.:format)       -> books#update
          DELETE /books/:id(.:format)       -> books#destroy

因此使用方法 PUT 和路径 '/books/:id' 的路径已经存在，你的 put '/books/:id' => 'books#soft_delete' 将永远不会被使用。这就是触发错误的原因：'ActionController::ParameterMissing in BooksController#update ' - 您的 link 点击触发了 BooksController#update 操作调用，这需要参数中的书键。

其次：我建议您从模型中删除方法 :soft_delete 和 :undelete。 Rails 提供方法 :toggle!用于即时写入数据库和 :toggle 用于更改值而不立即保存更改。所以你可以直接在控制器中写这样的代码：

book = Book.find_by(id: params[:id])
book.toggle!(:soft_deleted)

请注意，第 soft_deleted 列应该是布尔值才能使其生效。

你的link应该是这样的：

link_to 'Soft Delete', soft_delete_book_path(book), data: { method: :put }

ActionController::ParameterMissing 使用自定义路线

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