Ruby on rails 使用生成创建中未定义的方法

我一直在反复讨论这个问题，不明白为什么Rails 4会出错

我有3个模型，如下所示

我正在尝试创建一个与项目关联的节，并为nil:NilClass获得未定义的方法'sections'的命名错误

据我所知，我正在经历与创建与当前用户关联的项目时相同的过程

非常感谢您的帮助

user.rb

class User < ActiveRecord::Base
   devise :invitable, :database_authenticatable, :registerable,
     :recoverable, :rememberable, :trackable, :validatable
   has_many :projects
end

class Project < ActiveRecord::Base
   belongs_to :user
   has_many :sections
 end

class Section < ActiveRecord::Base
     belongs_to :project
end

Dr::Application.routes.draw do
  resources :projects do
    resources :sections
  end

  resources :sections

  root :to => "home#index"
  devise_for :users
end

def new
  @section = Section.new
end

def create
  @project = params[:project_id]
  @section = @project.sections.build section_params
  respond_to do |format|
    if @section.save
      format.html { redirect_to project_path(@section), :notice => 'Section was successfully created.' }
      format.xml  { render :xml => @section, :status => :created, :location => @section }
    else
      format.html { render :action => "new" }
      format.xml  { render :xml => @section.errors, :status => :unprocessable_entity }
    end
  end
end

private
def section_params
  params.require(:section).permit(:name)
end

部分\u controller.rb

class User < ActiveRecord::Base
   devise :invitable, :database_authenticatable, :registerable,
     :recoverable, :rememberable, :trackable, :validatable
   has_many :projects
end

class Project < ActiveRecord::Base
   belongs_to :user
   has_many :sections
 end

class Section < ActiveRecord::Base
     belongs_to :project
end

Dr::Application.routes.draw do
  resources :projects do
    resources :sections
  end

  resources :sections

  root :to => "home#index"
  devise_for :users
end

def new
  @section = Section.new
end

def create
  @project = params[:project_id]
  @section = @project.sections.build section_params
  respond_to do |format|
    if @section.save
      format.html { redirect_to project_path(@section), :notice => 'Section was successfully created.' }
      format.xml  { render :xml => @section, :status => :created, :location => @section }
    else
      format.html { render :action => "new" }
      format.xml  { render :xml => @section.errors, :status => :unprocessable_entity }
    end
  end
end

private
def section_params
  params.require(:section).permit(:name)
end

new.html.haml

= simple_form_for [@project, @section] do |f|
  = f.input :name
  = f.button :submit

---

我认为您应该更改控制器中的创建操作，如下所示：

def create
  @project = current_user.projects.find(params[:project_id])
  @section = @project.sections.new section_params
  respond_to do |format|
    if @section.save
      format.html { redirect_to project_path(@project), :notice => "Section for #{@project.name} was successfully created." }
      format.xml  { render :xml => @project, :status => :created, :location => @section }
    else
      format.html { render :action => "new" }
      format.xml  { render :xml => @section.errors, :status => :unprocessable_entity }
    end
  end
end

---

你对哪个项目有这个表格

= simple_form_for [@project, @section] do |f|
  = f.input :name
  = f.button :submit

我的意思是，从你得到@project的地方来看，如果你的表单像你在new.html.haml中说的那样处于单独的视图中，那么你的新方法也必须有@project

def new
  @section = Section.new
  @project = current_user.projects.find(:id)  # pass an id for which u are creating section
end

---

创建操作中的

@project

变量的内容是什么？@TomášDundáček我以为这样做是为了将项目传递到下一行？谢谢您的回复。不幸的是，这返回了一个错误，“找不到没有ID的项目”，我的路线是“/projects/1/sections/new”，谢谢，再加上@Mattherick，这就完成了任务。干杯