gistfile1.rb

#routes.rb

  get "blog/category/:category/" => "posts#by_category", as: :post_category
  get "blog/category/:category/index.html" => "posts#by_category"
  get "blog/page-:page/" => "posts#index", as: :blog
  get "blog/page-:page/index.html" => "posts#index"
  get "blog/:slug/" => "posts#by_slug", as: :post_slug
  get "blog/:slug/index.html" => "posts#by_slug"
  get "blog" => "posts#index", as: :blog
  get "blog/index.html" => "posts#index"
  get "rss.xml" => "posts#rss", format: :rss, as: :posts_rss

#posts_controller.rb

class PostsController < ApplicationController
  def index
    @posts = Post.order("created_at DESC")
    unless params[:admin]
      @posts = @posts.where(visible: true)
    end
    @posts = @posts.page(params[:page])
  end

  def rss
    @posts = Post.where(visible: true).order("created_at DESC").limit(20)
    respond_to do |format|
      format.rss { render layout: false }
    end
  end

  def by_slug
    @post = Post.where(slug: params[:slug]).first
    render action: :show
  end

  def by_category
    @posts = Post.order("created_at DESC").where("lower(keywords) = ?", params[:category].gsub(/\-/, ' '))
    unless params[:admin]
      @posts = @posts.where(visible: true)
    end
    @posts = @posts.page(params[:page])
    render action: :index
  end

end

#views/posts/index.html.erb
<% title "Blog of Tomas Varaneckas" %>
<div class="row blog">
  <%= render partial: "shared/nav" %>
</div>
<div class="row blog">
  <div class="span8">
    <% for post in @posts %>
      <div class="well post">
        <%= render :partial => 'post', locals: { post: post } %>
        <div class="comments-link">
          <%= link_to "0 Comments", "#{post_slug_path(post.slug)}#disqus_thread" %>
        </div>
      </div>
    <% end %>
    <%= paginate @posts %>
  </div>
  <div class="span4">
    <%= render :partial => 'categories' %>
  </div>

</div>
</table>

<% if params[:admin] %>
  <p><%= link_to "New Post", new_post_path %></p>
<% end %>