Rails 3 - Nested resources and polymorphic paths: OK to two levels, but break at three

Question

I\'m trying to do a simple family reunion site with: \"posts\", \"families\", \"kids\", and \"pictures\". Ideally I\'d like the routes/relationships to be structured this way:<

Answer 1

Have been having this exact same problem for a while. I have it working now, but it isn't beautiful :S

From a nested monster like:

http://localhost:3000/destinations/3/accommodations/3/accommodation_facilities/52

Your params object ends up looking like this:

action: show
id: "52"
destination_id: "3"
accommodation_id: "3"
controller: accommodation_facilities

where "id" represents the current model id (last on the chain) and the other ones have model_name_id

To correctly render another nested link on this page, you need to pass in an array of objects that make up the full path, eg to link to a fictional FacilityType object you'd have to do:

 <%= link_to "New", new_polymorphic_path([@destination, @accommodation, @accommodation_facility, :accommodation_facility_type]) %>

To generate this array from the params object, I use this code in application_helper.rb

def find_parent_models(current_model = nil)
    parents = Array.new

    params.each do |name, value|
      if name =~ /(.+)_id$/
        parents.push $1.classify.constantize.find(value)
      end
    end

    parents.push current_model

    parents
end

Then to automatically make the same link, you can merrily do:

 <%= link_to "New", new_polymorphic_path(find_parent_models(@accommodation_facility).push(:accommodation_facility_type)) %>

Any pointers on making this solution less sketchy are very welcome :]