posts_controller.rb

def create
    @post = Post.new(post_params)
    respond_to do |format|
      Rails.logger.info "*** format = #{format.inspect}"
      if @post.save
        format.html { redirect_to root_path }
        format.js # Will search for create.js.erb
      else
        format.html { render root_path }
      end
    end
  end