Ransack - Sorting association in show action

Question

Fully stuck on Ransack sorting with Associations. Want to sort the list of products from different brands.

Brands Model:

class Brand < ApplicationRecord
    has_many :products
end

Brand Controller:

def show
    @brand = Brand.find(params[:id])
    @q = @brand.products.ransack(params[:q])
end

Brand View:

<%= search_form_for @q, url: products_path(params[:id]) do |f| %>
      <%= f.search_field :brand_products_title_cont %>
      <%= sort_link(@q, :brand_products_id)%>
      <%= sort_link @q, :brand_products_title %>
<% end %>

I can filter on the product.title without problems, but sorting does not work. What is my mistake in thinking?

Here is the SQL output after clicking on the sorting by title:

  Brand Load (0.3ms)  SELECT  `brands`.* FROM `brands` WHERE `brands`.`id` = 2 LIMIT 1

  CACHE (0.0ms)  SELECT  `brands`.* FROM `brands` WHERE `brands`.`id` = 2 LIMIT 1  [["id", 2], ["LIMIT", 1]]

  Rendering brands/show.html.erb within layouts/application
  Product Load (19.5ms)  SELECT `products`.* FROM `products` WHERE `products`.`brand_id` = ‚BRANDNAME'

Answer 1

I solved this problem in the following way:

class Job < ApplicationRecord
 has_one :address
end

Address looks like

{ street, city, state, zipcode }

I wanted to sort on job.address.street

In my controller I have:

@q = Job.ransack(params[:query])
@q.sorts = params.dig(:q, :s) || 'id asc'

And in my view I have:

<%= sort_link(@q, :address_street) %>

Answer 2

The Ransack README has this to say about sorting with associations:

If you have trouble sorting on associations, try using an SQL string with the pluralized table ('departments.title','employees.last_name') instead of the symbolized association (:department_title), :employees_last_name).

In your case, that would look like this:

sort_link @q, 'products.title'

Answer 3

You are using ransack for @brand.products not for @brand

In this case you can try something like this in the View:

<%= search_form_for @q, url: brand_path(params[:id]) do |f| %>
    # Search if the name field contains...
    <%= f.search_field :title_cont %>
    <%= sort_link(@q, :id)%>
    <%= sort_link @q, :title %>
<% end %>