Rails Create article with other user not current_user - ruby-on-rails

Question

I would like to create an article with other user not current_user and for that I'm saving in a session the id to the other user and I recover this id with a collection in the view to this point everything work fine but when I'm trying to use my helper :selected_user into my articles controller with a if sentence doesn't work here is my code:
def new
if selected_user.present?
#article = selected_user.articles.build state: :step1
render_wizard
else
#article = current_user.articles.build state: :step1
render_wizard
end
end
so, I'm asking if the selected_user.present? I would like to create the article with this user_id but else I would like to create it with the current_user
my create method is:
def create
if selected_user.present?
step = :step1
#article = selected_user.articles.build article_params_step1
#article.state = step.to_s
if #article.save
redirect_to wizard_path(next_step, article_id: #article)
else
render_wizard
end
else
step = :step1
#article = current_user.articles.build article_params_step1
#article.state = step.to_s
if #article.save
redirect_to wizard_path(next_step, article_id: #article)
else
render_wizard
end
end
end
so, yeah when I run my view the controller jump to the else section.
just for clarify my selected_user not return nil but here is the implementation:
selections_controller.rb:
class SelectionsController < ApplicationController
before_action :authenticate_user!
def create
session[:selected_user_id] = params[:user][ :user_id]
redirect_to root_path
end
end
and in my application_controller.rb:
helper_method :selected_user
def selected_user
#selected_user ||= User.find(session[:selected_user_id])
end
and in the view:
<%= form_tag( { :controller => "selections", :action => "create" } , :class => "navbar-form navbar-left") do %>
<%= collection_select(:user, :user_id, User.all, :id, :name, prompt: "Escoge cliente")%>
<%= submit_tag 'Enviar' %>
<% end %>
if I try create an article without select an user from my collection appear this error:
Couldn't find User with 'id'=
but when I select my user from the collection everything works fine. so just I want when I don't select nothing create with the current_user.
Thanks for your time !
Regards !

Answer 1

The reason why you were seeing the error
Couldn't find User with 'id'=
when you haven't selected a user was that the session[:selected_user_id] was nil and your old selected_user with following code was throwing the error.
def selected_user
#selected_user ||= User.find(session[:selected_user_id])
end
User.find method expects either a single id or an array of ids. If you give a single id and if it finds the relevant record in the database then it will returns that instance. If you give an array of ids and if it finds those relevant records in the database, then it will return array of those instances. But if you pass nil to it, then it will through the error Couldn't find User with 'id'= as it won't find a relevant record.
But your updated selected_user implementation:
def selected_user
#selected_user ||= session[:selected_user_id] && User.find_by_id(session[:selected_user_id])
end
is working because, first you are checking for the existence of session[:selected_user_id] value and second you are using User.find_by_id instead of User.find.
User.find_by_id either returns a single instance of the record if it finds it in the database or will return nil if it doesn't find the record. It will never through an error.
Refer to ActiveRecord#find and ActiveRecord#find_by for more info.

Answer 2

I'm not sure why is working and what is the different but my solution for the problem it was to add this to my selected_user method:
def selected_user
#selected_user ||= session[:selected_user_id] && User.find_by_id(session[:selected_user_id])
end
and with that I don't have the nil error and entry to the if statement without errors.