Trying to add lists to my collections (form_for, routing)

Question

Hey guys I am trying to be able to add lists to my collections. I am new to rails any help would be appreciated. Currently I am trying to build a form to make a new list, but the new/create actions seem to be messed up.

The lists will end up living in the collections show view later via ajax.

Ultimately the goal is for each user to own multiple collections and in each collection there will be multiple lists, in each lists multiple items.

Collections

class CollectionsController < ApplicationController

def index
    @user = User.find(current_user)
    @collection = Collection.where(:user_id => current_user.id)
end

def new
    @collection = Collection.new
end

def show
    @collection = Collection.find(params[:id])
    @list = List.all
end

def create
    @collection = Collection.new(collection_params)
    @collection.user_id = current_user.id
    # render :text => CGI.escapeHTML(@collection.inspect)
    if @collection.save
        redirect_to root_path(@user)
    else
        render 'new'
    end
end

def edit
    @collection = Collection.find(params[:id])
end

def update
    if @collection.update(collection_params)
        redirect_to root_path(@user)
    else
        render 'edit'
    end
end

def destroy
    @collection.destroy
    redirect_to root_path(@user)
end

private
  def collection_params
    params.require(:collection).permit(:alias, :notes, :visibility)
  end
  def find_collection
    @collection = @user.collection.find(params[:id])
  end
end

Lists

class ListsController < ApplicationController
def index
    @list = List.all
end

def new
    @list = List.new
end

def create
    @collection = Collection.find(params[:collection_id])
    @list =
    @collection.lists.create(comments_params)
    if @collection.lists.save
    redirect_to root_path(@user)
    else
        render 'new'
    end
end
end

Users

class UsersController < ApplicationController

def index
    @user = User.find(current_user)
    @collection = Collection.where(:user_id => current_user.id)
    @user.collection = Collection.where(:user_id => current_user.id)
    # render :text => CGI.escapeHTML(@collection.inspect)
end
end

The link I was trying

<%= link_to '<i class="fa fa-plus-square"></i> Add Subcategory'.html_safe, new_collection_list_path(@collection.id)  %>

Current routes

devise_scope :user do
authenticated :user do
  root 'collections#index', as: :authenticated
   resources :collections do
    resources :lists
  end
end

Failed form_for

<%= form_for([@collection, @collection.lists.build]) do |f| %>

<% end %>

Models

Users has_many :collections


Collections belong_to :user
has_many :lists


Lists belong_to :collection

Answer 1

Change your ListsController new and create actions to the following:

def new
  @collection = Collection.find(params[:collection_id])
end

def create
  @collection = Collection.find(params[:collection_id])
  @list = @collection.lists.build(params[:list])
  if @list.save
    redirect_to root_path(@user)
  else
    render 'new'
  end
end