How to call a method from controller using link_to? - ruby-on-rails

Question

I want my app to add a book to current_user when he clicks the link. My code seems to be ok, there are no errors but after user clicks the link nothing happens.
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
In my index view I have
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}
So, what am I doing wrong? Why my method add_to_books_i_read does nothing? The table in database book_users doesn't record anything after clicking this link_to, but it works well itself (I checked via console). What can I do? How to make users add books through the method and how to call this method correctly? Every help would be appreciated, thank you!

Answer 1

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

Answer 2

The first, method in the link_to is the symbol of HTTP verb so you can not pass your function in the controller
To define and use new action on you controller you need to define route for that see here

Answer 3

Also try to organize your routes as (note member section)
resources :books do
member do
get :add_to_books_i_read
end
end
and see Prefix Verb column in rake routes output.

Answer 4

From #Ioannis Tziligkakis, I edited a bit.
Try:
# 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 5

Try this:
# 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 6

Since add_to_books_i_read is a controller action method you should update your routes to include this action for books resources in order to play nicely with Rails way of doing thing in a resourceful way. You also get to use a URL helper for this path that will look like this:
/books/:id/add_to_books_i_read
Your code could look like this:
# 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 7

Oh God. With your advise help I've finally got it! So,
Controller:
def add_to_books_i_read
current_user.books << Book.find(params[:id])
redirect_to(:back) #this line
end
In routes
resources :books do
member do
get :add_to_books_i_read
end
end
index view
-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)
Thank you all for your help! I'm really really grateful! :)