Question

I have a 2 level nesting objects that i need help with

My routes look like this to normalise the url abit. instead of having a url that looks like this /projects/1/tasks/3/comments/3.

resources :projects do
  resources :tasks
end

resources :tasks do
  resources :comments
end

Model has the ‘has_many’, belongs_to methods.

I can create comments under each task and display them under the tasks, but on the ‘show’ template of the comments i would like to display a link back to the tasks, which i get an error because the tasks controller is asking for a project_id?

How would this normally done when dealing with 2 level nesting?

Answer 1

I would do

resources :projects, :shallow => true do
  resources :tasks do
    resources :comments
  end
end

Which is basically what you’re doing except you can’t generate a projects_task member path(ie projects/1/tasks/1) anymore they’d all just be task member paths(ie ‘/tasks/1’).
Member paths include show, update, delete, edit

But the project_tasks collection paths(ie projects/1/tasks) would still be available.
Collection paths include index, create, new

comment paths wouldn’t change. All comment paths would still include the task/:task_id prefix.

Checkout the resources documentation for more info on that (also more info on member and collection also on that page.)

But to actually solve your problem

You need to look up the project_id when you link back to the project_tasks index. So you would need to do

<%= link_to "Project Tasks Index", project_tasks_path(@task.project) %>

That way the Task#index knows where the parent project is. This is the solution for both implementations.

Check out the UrlFor documentation for more info on that.

If you want access to a @project variable in a Comment view

Then you just need to look up the project in the controller instead of at a view level. So basically

class CommentsController < ApplicationController
  def show
    @task = Task.find(params[:task_id])
    @comment = @task.comments.find([:id])

    @project = @task.project
  end
end