I have field to input data of post

<%= simple_form_for @post, remote: true do |f| %>

  <%= f.error_notification %>

    <%= f.input :title %>

    <%= f.button :submit %>

 <% end %>

In model I have validation_presence_of :title, but when I confirm button without filling title it doesn't create new object. But why it just doesn't show that title can't be blank?

My new and create in controller:

 def new

    @post = Post.new

  end



  def create

    @post = Post.new(post_params)



    respond_to do |format|

      if @post.save

        format.html { redirect_to :back, notice: 'Post was successfully    created.' }

        format.js

      else

        format.html { redirect_to :back }

        format.js

      end

   end

 end

   private:

   def post_params

      params.require(:post).permit(:title)

    end