Filtering an Index - ruby-on-rails

Question

I have the following index method
def index
#user = User.find_by_username(params[:user_id])
#search = #user.collections.where(status: params[:status]).search(params[:q])
#search.sorts = 'created_at desc' if #search.sorts.empty?
#collections = #search.result.paginate(page: params[:page])
end
I can then use the following links to display different indexes with that one action
<%= link_to "Collection", user_collections_path(current_user, :status => "Got") %>
<%= link_to "Wantlist", user_collections_path(current_user, :status => "Want") %>
But I want to also be able to link things like this, using other fields to filter the index
<%= link_to "Assembled", user_collections_path(current_user, :progress => "Assembled") %>
and I can't see how to write that. Should I be using scopes or should I have alternative methods in my controller? Is my initial "where" filter a bad way of doing this in the first place?

Answer 1

The best way I found to do this is with the has_scope gem.
Installed that. Named scopes in my model as follows
scope :assembled, -> { where(progress: 'Assembled') }
scope :got, -> { where(status: 'Got') }
scope :want, -> { where(status: 'Want') }
Added the has_scope fields to the controller
has_scope :got, :type => :boolean
has_scope :want, :type => :boolean
has_scope :assembled, :type => :boolean
Then my index method as follows
def index
#user = User.find_by_username(params[:user_id])
#search = apply_scopes(#user.collections).search(params[:q])
#search.sorts = 'created_at desc' if #search.sorts.empty?
#collections = #search.result.paginate(page: params[:page])
end
Then I can link to the index with any combination of those scopes like this
<%= link_to collection, user_collections_path(#user, got: true) %>
<%= link_to assembled, user_collections_path(#user, got: true, assembled: true) %>
No routes and no extra methods. Very clean and expandable.

Answer 2

Use a Gem instead
This is a solved problem. I would use a gem like ransack to do this rather than re-inventing the wheel. It has great helper methods to provide any kind of filtering that you would need.

Answer 3

Routes
Further to San's answer, you'll need to create routes to handle any data you wish to send to your index (for filtering):
You'd do something like this:
#config/routes.rb
resources :users, except: :show do
collection do
get "(:query)", action: :index #-> domain.com/users/:query
end
end
This will allow you to create links like this:
<%= link_to "Link", users_path(current_user, query: "whatever") %>
--
Controller
Inside your controller, all the links will hit your index action, so you'll just need some conditions to make sure you can handle a "non search" request:
def index
#user = User.find_by_username(params[:user_id])
if params[:status].present? && params[:q].present?
#search = #user.collections.where(status: params[:status]).search(params[:q])
#search.sorts = 'created_at desc' if #search.sorts.empty?
#collections = #search.result.paginate(page: params[:page])
end
end