导轨 - NoMethodError未定义的方法

我正在构建一个应用程序（以下Michael Hartl's chapter 11），用户可以跟随由其他用户创建的项目。导轨 - NoMethodError未定义的方法

我创建了一个ProjectRelationship模型来存放两个组件：用户的follower_id和项目的projectuser_id。外键已经设置好了。

现在，我的_follow_form.html.erb页面根据current_user是否跟随项目呈现“跟随”或“取消关注”。下面附上了我的代码。

现在，每个项目展示页面都会生成关注按钮。当我点击按钮生成_follow.html.erb后，按照相应的项目。

但是当我按下 “取消关注” 我得到一个错误：

NoMethodError in ProjectRelationshipsController#destroy 
undefined method `unfollow_project!' for #<User:0x007f9ed83dd6b8> 

Application Trace | Framework Trace | Full Trace 
app/controllers/project_relationships_controller.rb:12:in `destroy'

schema.rb

create_table "project_relationships", :force => true do |t| 
    t.integer "follower_id" 
    t.datetime "created_at",  :null => false 
    t.datetime "updated_at",  :null => false 
    t.integer "projectuser_id" 
end 

add_index "project_relationships", ["projectuser_id"], :name => "index_project_relationships_on_projectuser_id"

的routes.rb

resources :projects do  
    resources :comments 
    member do 
    get :following 
    end 
end 
resources :project_relationships, only: [:create, :destroy]

project_relationship.rb

class ProjectRelationship < ActiveRecord::Base 
    attr_accessible :projectuser_id 

    belongs_to :user, foreign_key: "follower_id" 
    belongs_to :project, foreign_key: "projectuser_id" 
end

project.rb

has_many :project_relationships, foreign_key: "projectuser_id" 
has_many :favorited_by, through: :project_relationships, source: :user

user.rb

has_many :project_relationships, foreign_key: "follower_id" 
has_many :followed_projects, through: :project_relationships, source: :project 

def following_project?(project) 
    project_relationships.find_by_projectuser_id(project.id) 
end 

def follow_project!(project) 
    project_relationships.create!(projectuser_id: project.id) 
end 

def project_unfollow!(project) 
    project_relationships.find_by_projectuser_id(project.id).destroy 
end

project_relationships_controller.rb

class ProjectRelationshipsController < ApplicationController 

def create 
    @project = Project.find(params[:project_relationship][:projectuser_id]) 
    current_user.follow_project!(@project) 
    redirect_to @project 
    end 

    def destroy 
    @project = ProjectRelationship.find(params[:id]).project 
    current_user.unfollow_project!(@project) 
    redirect_to @project 
    end 
end

项目/ show.html.erb

<%= render 'follow_form' if signed_in? %>

项目/ _follow_form.html.erb

<% if current_user.following_project?(@project) %> 
    <%= render 'unfollow' %> 
<% else %> 
    <%= render 'follow' %> 
<% end %>

项目/ _follow.html.erb

<%= form_for(current_user.project_relationships.build(projectuser_id: @project.id)) do |f| %> 
    <div><%= f.hidden_field :projectuser_id %></div> 
    <%= f.submit "Follow", class: "btn btn-large btn-primary" %> 
<% end %>

个

项目/ _unfollow.html.erb

<%= form_for(current_user.project_relationships.find_by_projectuser_id(@project), 
     html: { method: :delete }) do |f| %> 
    <%= f.submit "Unfollow", class: "btn btn-large" %> 
<% end %>

项目/ _followerstats.html。ERB