Can't change root route rails - ruby-on-rails

Question

I'm creating a simple Todo list application in rails and I have the next problem:
I have a task that belongs_to project
I've created a template - projects/show.html.erb
And I can't set it to be the root page of my app, as I can see from the debugger - root is always projects#index action
P.S. I need show to be the root page cause I can't use this form in index action
<%= form_for [#project, #task],remote: true do |f| %>
<%= f.input :body,class: 'form-control' %>
<%= f.submit 'Add task', class: 'btn' %>
<% end %>
projects controller
class ProjectsController < ApplicationController
before_action :load_project, only: [:show, :edit, :update, :destroy]
before_action :authenticate_user!
def index
#projects = current_user.projects unless current_user.nil?
end
def show
#task = #project.tasks.new
end
def new
#project = current_user.projects.new
end
def edit
end
def create
#project = current_user.projects.create(project_params)
if #project.save
redirect_to root_path
else
render :new
end
end
def update
if #project.update(project_params)
redirect_to #project
else
render :edit
end
end
def destroy
#project.destroy
redirect_to projects_path
end
private
def load_project
begin
#project = Project.find(params[:id]) #raises an exception if project not found
rescue ActiveRecord::RecordNotFound
redirect_to projects_path
end
end
def project_params
params.require(:project).permit(:name, :user_id)
end
end
Routes.rb
Rails.application.routes.draw do
devise_for :users, :controllers => { :omniauth_callbacks => "callbacks" }
# For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
root 'projects#index'
resources :projects do
resources :tasks
end
end
And routes generated by rake routes
todo$ rake routes
Prefix Verb URI Pattern Controller#Action
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /users/sign_out(.:format) devise/sessions#destroy
user_facebook_omniauth_authorize GET|POST /users/auth/facebook(.:format) callbacks#passthru
user_facebook_omniauth_callback GET|POST /users/auth/facebook/callback(.:format) callbacks#facebook
user_password POST /users/password(.:format) devise/passwords#create
new_user_password GET /users/password/new(.:format) devise/passwords#new
edit_user_password GET /users/password/edit(.:format) devise/passwords#edit
PATCH /users/password(.:format) devise/passwords#update
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) devise/registrations#cancel
user_registration POST /users(.:format) devise/registrations#create
new_user_registration GET /users/sign_up(.:format) devise/registrations#new
edit_user_registration GET /users/edit(.:format) devise/registrations#edit
PATCH /users(.:format) devise/registrations#update
PUT /users(.:format) devise/registrations#update
DELETE /users(.:format) devise/registrations#destroy
root GET / home#index
project_tasks GET /projects/:project_id/tasks(.:format) tasks#index
POST /projects/:project_id/tasks(.:format) tasks#create
new_project_task GET /projects/:project_id/tasks/new(.:format) tasks#new
edit_project_task GET /projects/:project_id/tasks/:id/edit(.:format) tasks#edit
project_task GET /projects/:project_id/tasks/:id(.:format) tasks#show
PATCH /projects/:project_id/tasks/:id(.:format) tasks#update
PUT /projects/:project_id/tasks/:id(.:format) tasks#update
DELETE /projects/:project_id/tasks/:id(.:format) tasks#destroy
projects GET /projects(.:format) projects#index
POST /projects(.:format) projects#create
new_project GET /projects/new(.:format) projects#new
edit_project GET /projects/:id/edit(.:format) projects#edit
project GET /projects/:id(.:format) projects#show
PATCH /projects/:id(.:format) projects#update
PUT /projects/:id(.:format) projects#update
DELETE /projects/:id(.:format) projects#destroy

Answer 1

Why do you want the index to be show page? Well, how can you do that? The show action requires a id to be passed to the controller so that a particular project can be displayed to the user. How can you pass in a id when the user is requesting for /?
Does that make sense?
I would suggest you to leave the root to the index page. In the index view, link each project to its show page. Its unnecessary to have a nested form in the index page.
Or if you want to list all projects and tasks in the root page, modify your index view to loop through each project's tasks.
#projects.each do |project|
# display project's information
project.tasks.each do |task|
# display the task information
# display a new task button
end
end
But you can't display the nested form like you asked. Because the form requires #project and #task which you can't determine in the index action. Maybe you can add remote: true to the "New task" and then trigger a JS response to render the form in a modal.
If this sounds new to you, please see https://launchschool.com/blog/the-detailed-guide-on-how-ajax-works-with-ruby-on-rails
This will walk through you using AJAX in your rails application.
Hope this helps!