Rails validation error message is not displaying - ruby-on-rails

Question

I have tried multiple methods to show error message from views, but it is not appearing.
<%= form_for #article do |f| %>
<% if #article.errors.any? %>
<div id="error_explanation">
<h2>
<%= pluralize(#article.errors.count, "error") %> prohibited
this article from being saved:
</h2>
<ul>
<% #article.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<p>
<%= f.label :title %><br>
<%= f.text_field :title %>
</p>
<p>
<%= f.label :text %><br>
<%= f.text_area :text %>
</p>
<p>
<%= f.submit %>
</p>
<% end %>
_form.html.erb
<center>
<h1>New article</h1>
<%= render 'form' %>
<%= link_to 'Back', articles_path %>
</center>
new.html.erb
class Article < ActiveRecord::Base
#attr_accessible :title, :text
has_many :comments, dependent: :destroy
validates :title, presence: true
end
article.rb
Rails.application.routes.draw do
root "articles#index"
resources :articles do
resources :comments
end
end
routes.rb
class ArticlesController < ApplicationController
http_basic_authenticate_with name: "deba", password: "12345", except: [:index, :show]
def index
#articles = Article.all
end
def new
#article = Article.new
end
def show
#article = Article.find(params[:id])
end
def create
#article = Article.new(article_params)
if #article.save
redirect_to #article
else
render 'new' ##article.errors, status: :unprocessable_entity
end
end
def edit
#article = Article.find(params[:id])
end
def update
#article = Article.find(params[:id])
if #article.update(article_params)
redirect_to #article
else
render 'edit'
end
end
def destroy
#article = Article.find(params[:id])
#article.destroy
redirect_to articles_path
end
private
def article_params
params.require(:article).permit(:title, :text)
end
end
articles_controller.rb
Kindly help me. I tried it, validation is working as I can check that if there is no title it redirect me to new page without saving it but not appearing the error messages.

Answer 1

The problem is with your redirecting - it causes the browser to initiate a new request and then you lose all the data (including the instance variables where the error is stored). Instead of redirecting you should simply render the "new" partial when article is invalid.
You haven't posted your controller code but this should give you a direction
if #article.save
# whatever you wanna do if its valid
else
render "new" # render the view without redirecting
end

Answer 2

try to edit your controller:
class ArticlesController < ApplicationController
before_action :initialize_article, only: [:new, :create]
...
def new
end
def create
if #article.update(article_params)
redirect_to #article
else
render :new
end
end
....
private
def initialize_article
#article ||= Article.new
end
end