how to make dynamic nested routes on rails? - ruby-on-rails

Question

I'll explain when open www.domain.com/:id should be check the :id is a page then use
get ':id' => 'pages#show'
else if :id is a Category use
get ':category' => 'categories#show'
sorry for my english
get ':page' => 'pages#show'
resources :categories, :path => '/' do
resources :posts, :path => '/'
end

Answer 1

constraints for routes is way to go, but I would suggest a bit different solution for your problem.
Consider creating custom Constraint objects, which will query the database in order to check if Post or Category exists:
app/lib/post_constraint.rb
class PostConstraint
def matches?(request)
Post.exists?(request[:id])
end
end
app/lib/category_constraint.rb
class CategoryConstraint
def matches?(request)
Category.exists?(request[:id])
end
end
In your app/config/routes.rb
get ":id" => "posts#show", constraints: PostConstraint.new
get ":id" => "categories#show", constraints: CategoryConstraint.new
You have to be aware of the fact, that id is very poor candidate for such comparison, because the Post is checked in first place, and if there is record matching, the "posts#show" will be accessed, and CategoryConstraint wot be even bothered.
For more, check the documentation.
You should consider adding a slug for both models to easier serve exactly what user expects to see. For this purpose, try gem friendly_id.
Hope that helps! Good luck!

Answer 2

why dont you write something like this:
routes.rb
get '/:category_id/:post_id', to: 'categories#post'
and in your categories_controller.rb
def post
#params[:category_id] and params[:post_id] will contain the params from the url
end

Answer 3

Couple of solutions
If your post id and category id follow a pattern you can add constraints to your routes
1)
get ':post_id' => 'posts#show', :constraints => { :id => /[A-Z]\d{5}/}
get ':category_id' => 'categories#show', :constraints => { :id => /[1-9]\d{5}/ }
2)
Add a custom method where both post_id/category_id routes point, in that check if the id is a post id or category id and based on that render the page