如何使用 link_to 从控制器调用方法？

Question

我希望我的应用在他单击 link 时向 current_user 添加一本书。我的代码似乎没问题，没有错误，但是在用户点击 link 之后什么也没有发生。

book.rb:

has_many :book_users
has_many :users, through: :book_users

user.rb:

has_many :book_users
has_many :books, through: :book_users

book_user.rb:

belongs_to :book
belongs_to :user

books_controller.rb:

before_action :is_admin?, except: [:book_params, :add_to_books_i_read, :index]
before_filter :authenticate_user!
expose(:book, attributes: :book_params)
expose(:books)


  def create
    if book.save
      redirect_to(book)
    else
      render :new
    end
  end

  def update
    if book.save
      redirect_to(book)
    else
      render :edit
    end
  end

  def add_to_books_i_read(book_id)
    current_user.books << Book.find(book_id)
  end

在我的索引视图中我有

ul
  -books.each do |book|
    li
      = link_to "#{book.name}", book_path(book)
      = link_to "  Add to my books", {:controller => "books", method: :add_to_books_i_read, book_id: :book.id}

那么，我做错了什么？为什么我的方法 add_to_books_i_read 什么都不做？单击此 link_to 后，数据库 book_users 中的 table 不会记录任何内容，但它本身运行良好（我通过控制台检查过）。我能做什么？如何让用户通过该方法添加图书以及如何正确调用该方法？我们将不胜感激，谢谢！

Answer 1

  = link_to "  Add to my books", {:controller => "books", action: :add_to_books_i_read, book_id: :book.id}

Answer 2

首先，link_to中的method是symbol of HTTP verb所以你不能在控制器中传递你的函数要在您的控制器上定义和使用新操作，您需要为该控制器定义路由 see here

Answer 3

由于 add_to_books_i_read 是一个控制器操作方法，您应该更新您的路由以包含针对 books 资源的此操作，以便与 Rails方法。您还可以为此路径使用 URL 帮助器，如下所示：

/books/:id/add_to_books_i_read

您的代码可能如下所示：

# config/routes.rb
resources :books do
  get :add_to_books_i_read, on: :member
end

# app/controller/books_controller.rb
def add_to_books_i_read
  current_user.books << Book.find(params[:id])
  # redirect or other logic
end

# app/views/books/index.html.haml
ul
  - books.each do |book|
    li
      = link_to "#{book.name}", book_path(book)
      = link_to "Add to my books", add_to_books_i_read_book_path(book)

Answer 4

也尝试将您的路线组织为（注意会员部分）

resources :books do 
  member do
    get :add_to_books_i_read
  end
end

并查看 rake 路由输出中的 Prefix Verb 列。

Answer 5

来自@Ioannis Tziligkakis，我做了一些编辑。

尝试：

# config/routes.rb
resources :books do
  member do
    get :add_to_books_i_read
  end
end

# app/controller/books_controller.rb
def add_to_books_i_read
  current_user.books << Book.find(params[:id])
  # redirect or other logic
end

# app/views/books/index.html.haml
ul
  - books.each do |book|
    li
      = link_to "#{book.name}", book_path(book)
      = link_to "Add to my books", add_to_books_i_read_book_path(book.id)

Answer 6

试试这个：

# config/routes.rb
resources :books do
  # just not about method:
  # use get for request, search
  # use put for update
  # use post for create
  # use delete for destroy
  put :add_to_books_i_read, on: :member
end

# app/controller/books_controller.rb
def add_to_books_i_read
  @book = Book.find(params[:id])
  current_user.books << @book
  respond_to do |format|
    format.js
  end
end

# app/views/books/index.html.haml
ul
  - books.each do |book|
    li{:id => "book_#{book.id}"}
      = render "links", book: book

# add field: app/views/books/_links.html.haml
= link_to "#{book.name}", book_path(book)
= link_to "Add to my books", add_to_books_i_read_book_path(book), method: :put, remote: true

# add field: app/views/books/add_to_books_i_read.js.erb
$("#book_<%= @book.id %>").html("<%= j render 'books/links', book: @book %>")

Answer 7

天哪。在您的建议帮助下，我终于明白了！所以，

控制器：

def add_to_books_i_read
    current_user.books << Book.find(params[:id])
    redirect_to(:back) #this line
end

在路线中

resources :books do
    member do
      get :add_to_books_i_read
    end
end

索引视图

-books.each do |book|
    li
      = link_to "#{book.name}", book_path(book)
      = link_to  "       Add to my books", add_to_books_i_read_book_path(book)

谢谢大家的帮助！我真的真的很感激！ :)

如何使用 link_to 从控制器调用方法？

How to call a method from controller using link_to?

ruby

ruby-on-rails

link-to