Rails ajax error while creating - ruby-on-rails

Question

Hello guys I want use ajax in my rails application :
Here is my routes.rb file
ExampleAjax::Application.routes.draw do
root 'users#index'
resources :users
end
my controller file
class UsersController < ApplicationController
def index
#users = User.all
#user = User.new
end
def create
#user = User.new(user_params)
respond_to do |format|
if #user.save
format.html { redirect_to #user, notice: 'User was successfully created.' }
format.js {}
format.json { render json: #user, status: :created, location: #user }
else
format.html { render action: "new" }
format.json { render json: #user.errors, status: :unprocessable_entity }
end
end
end
private
def user_params
params.require(:user).permit(:fname)
end
end
My view files
index.html.erb
<b>Users</b>
<ul id="users">
<% #users.each do |user| %>
<%= render user %>
<% end %>
</ul>
<br>
<%= form_for(#user, remote: true) do |f| %>
<%= f.label :fname %><br>
<%= f.text_field :fname %>
<%= f.submit %>
<% end %>
new.html.erb
<%=form_for(#user, remote: true) do |f|%>
<p>
<%= f.label :fname %><br>
<%= f.text_field :fname %>
</p>
<p>
<%= f.label :lname %><br>
<%= f.text_field :lname %>
</p>
<p>
<%= f.submit %>
</p>
<% end %>
_user.html.erb
<li><%= user.fname %></li>
_create.js.erb
$("<%= escape_javascript(render #user) %>").appendTo("#users");
And my problem is when I click create user
I got the following error in console
POST http://localhost:3000/users 500 (Internal Server Error)

Answer 1

Your code is hitting this block:
format.js {}
Which has nothing defined in it, so your app will try to do what it normally does, ie. render the view for the action you are in.
You are in a create action, and your format is js, so it will try to render create.js.erb.
You should rename your _create.js.erb to remove the underscore.

Answer 2

Ajax
I want use ajax in my rails application
To give you some info about Ajax, it's basically integrated in your application already:
Ajax is a group of interrelated web development techniques used on the
client-side to create asynchronous web applications
It's basically a way to send an asynchronous request to your web app (through javascript). Asynchronous essentially means you're sending requests out of scope of the typical HTTP "synchronous" request structure
HTTP works by responding to requests. Each click you perform is sending a request to your server, which responds with data. Synchronous requests are ones you perform in order, whereas asynchronous "ajax" ones are sent independently
Code
Your problem is you don't have a create.js.erb file:
respond_to do |format|
format.html #-> action.html.erb
format.js #-> action.js.erb
end
Unless you call some other methods in this block (such as render nothing), Rails will look for your action.js.erb file in your views directory
Rails
Rails handles all requests equally, and determines if it's an ajax request using the ActionDispatch::Http::MimeNegotiation class
This means you don't have to do anything "special" to use Ajax -- just send the requests to your routes, and handle them in the backend using respond_to do |format|