Question

Learning ruby on rails, playing around with routes and path methods.
I have built a fairly simple application with the models “Book” and “Author”. Each author can have many books, every book belongs to an author, etc.

I have an authors controller with the method #list that lists all authors. When it does that, it also echoes out all their books. Now I would like each book to point to books#show with this nifty path method I found.

Here is my snippet:

<% @authors.each do |author| %>
    <li><%= author.name %></li>
    <ul>
        <% author.books.all.each do |book| %>
            <li><%= link_to book.name, controller: :books, action: :show, id: book.id %></li>
        <% end %>
    </ul>
<% end %>

With this link_to book.name, controller: :books, action: :show, id: book.id it works fine, but something tells me the same can be achieved much easier. If I use books_show_path(book) it won’t work.

My routes look like the following:

root to: ‘authors#list’

match 'authors/list' => 'authors#list'
match 'books/list' => 'books#list'
match 'authors/:id/delete' => 'authors#delete'
match 'authors/:id/show' => 'authors#show'
match 'books/:id/show' => 'books#show'

What am I doing wrong here? What do I need to do to make books_show_path(book) work?

Answer 1

Check out Resource Routing section of Rails Guides.

In short, the convention is that you define resources :books in routes, that will route /books to index action and /books/123 to show action etc. You will also have some helper methods to generate the path:

book_path(book) #=> /books/123
books_path #=> /books

In fact, link_to and a bunch of other methods can generate path from object itself:

link_to book.name, book # will also call book_path(book) under the hood