Set up the routes⌗

Open the routes.rb file and define 3 new rules.

Rails.application.routes.draw do
  get 'posts/index'
  get 'posts/show/:file_name', to: 'posts#show', as: 'detail'
  get 'tags/:tag_name', to: 'posts#tag', as: 'tag'
  
  root "posts#index"
end

Make the default root path point to the post index page, that is what we expected.

Create controller⌗

In the terminal, use the rails generator to create a new controller, as respect to the rails’ convention, I will use posts as the controller’s name instead of post.

rails g controller posts index show tag

The post list page⌗

The logic of the post list page is quite straightforward, fetch 100 posts information from post set, to keep it as simple as possible, I did not implement the pagination feature, however since the I selected zset as the primary data structure of post list, it indeed has the potential to paginate all the posts. At the end of the code, I get all the tags from Redis as well.

def index
    key = Rails.configuration.redis['post_set_key']
    tags_key = Rails.configuration.redis['tag_set_key']
    @posts = @r.zrange(key, 0, 100, rev: false)
    Rails.logger.info(@posts)
    @tags = @r.smembers(tags_key)
  end

The post detail page⌗

The post detail page is kind of complicated, the basic idea is trying to get the post detail from redis, if the article’s content does not exist then open the markdown file and render the content directly, at this situation, I will not parse the metadata of the post, in that way the tags will be empty and a line of json string will display at the top of the post page, this is a reasonable feature downgrade.

def show
    full_file_name = params[:file_name] + ".md"
    file_name = params[:file_name].strip
    file_path = File.join(Rails.root, "posts", full_file_name)
    key_prefix = Rails.configuration.redis['post_prefix']
    key = key_prefix + file_name
    @tags = []
    if @r.exists?(key)
      data = JSON.load @r.get(key)
      @md_content = data['content']
      @tags = data['tags']
      Rails.logger.info("Load from redis")
    else
      if File.exists?(file_path)
        Rails.logger.info("Load from file #{file_path}")
        File.open(file_path) do |f|
          @md_content = f.read
        end
      else
        raise ActionController::RoutingError.new('NOT FOUND')
      end #if 
    end #if
  end

The tags list page⌗

This page is a little bit boring, just get all the tags from redis then render them using the post list page’s template.

def tag
    tag = params[:tag_name].strip
    tag_prefix = Rails.configuration.redis['tag_prefix']
    tags_key = Rails.configuration.redis['tag_set_key']

    key = tag_prefix + tag
    @posts = @r.smembers(key)
    @tags = @r.smembers(tags_key)
    render :index
  end

The view⌗

I occasionally found a creative and neat tailwind css blog template months ago, I’d like to use the elegant implementation as much as possible. It is a bit long-winded to list the files inside one by one, you can find all the view files I modified a little bit here.

Next step⌗

Our blogging application is now complete, next step I am going to deploy it to a vm using capistrano. It is challenging for to get it all done for beginners, but no worries let’s do it step by step in the next part.