Devit on Rails

Posted by PRbsas on February 24, 2018

Devit is a link aggregator site, similar to Reddit or Hacker News, where a user can submit a link and content to a community, as well as comment on and vote on those submissions.

rails new devit !

Authentication with Devise and OmniAuth with a GitHub strategy

The Devise and OmniAuth Authentication with Rails post I wrote describes how I applied them both to authenticate in devit.

Models and Associations

The application has a series of models with has_many and belongs_to associations, as well as has_many :trough ones.

The User model makes use of source: to name the association between User and Post as :contributions

class User < ApplicationRecord
  has_many :communities

  has_many :posts
  has_many :contributions, through: :posts, source: :community

  has_many :comments

  has_many :user_flairs
  has_many :flairs, through: :user_flairs
end

The Community model specifies a custom class_name and foreign_key for the User class to reference it as poster. A Community belongs_to its poster.

class Community < ApplicationRecord
  belongs_to :poster, class_name: 'User', foreign_key: 'user_id'

  has_many :posts, dependent: :destroy
  has_many :posters, through: :posts, source: :user
end

class Post < ApplicationRecord
  belongs_to :user
  belongs_to :community

  has_many :comments, dependent: :destroy

  has_many :tags
  accepts_nested_attributes_for :tags, reject_if: :all_blank
end

A Comment belongs_to a Post and a User. The comment table is a join table.

class Comment < ApplicationRecord
  belongs_to :post
  belongs_to :user
end

A Tag (or category) belongs_to a Post, and a Post has_many tags.

class Tag < ApplicationRecord
  belongs_to :post
end

class Flair < ApplicationRecord
  has_many :user_flairs
  has_many :users, through: :user_flairs
end

A UserFlair belongs_to a User and a Flair. The user_flairs table is a join table that adds an extra attribute, experience_level.

class UserFlair < ApplicationRecord
  belongs_to :user
  belongs_to :flair
end

Scope

Through a scope, the Post model adds a class method for retrieving the most recent posts.

class Post < ApplicationRecord
  scope :recent, -> { order('posts.created_at DESC').limit(10) }
end

To make this feature visible a route and controller action were added:

get 'posts/recent', to: 'posts#recent'

class PostsController < ApplicationController
  def recent
    @recent_posts = Post.recent
    render :recent
  end
end

As well as a view, that uses the _post partial to render:

<h1>Recent Posts</h1>

<section id="list-posts" class="recent">
  <ul>
    <% @recent_posts.each do |post| %>
      <%= link_to community_post_path(post.community, post) do %>
        <%= render partial: 'post', locals: { post: post } %>
      <% end %>
    <% end %>
  </ul>
</section>

Custom Attribute Writer

The User model includes a custom attribute writer responsible for finding and creating a flair by name through a nested form in users/edit.

class User < ApplicationRecord

  def flairs_attributes=(flairs_attributes)
    flairs_attributes.values.each do |flairs_attribute|
      if flairs_attribute['name'] != nil
        flair = Flair.find_or_create_by(name: flairs_attribute['name'])
        self.user_flairs.build(flair: flair, experience_level: flairs_attribute['user_flairs']['experience_level'])
      end
    end
  end
end

Params hash for updating a User:

{"utf8"=>"✓",
 "_method"=>"patch",
 "authenticity_token"=>"PcWvSoJCNeT9XoHNwGNMhAp2XnEYto+P5f2VFYCkCth2tDafYi/eKGFXw10tUgis1hTxV+CA81sqCkooy1taCw==",
 "user"=>
  {"name"=>"Paula Ramirez Pitzen",
   "username"=>"PRbsas",
   "avatar_url"=>"https://avatars0.githubusercontent.com/u/19231820?v=4",
   "bio"=>"Architect - Designer - Web Developer",
   "github_profile_url"=>"https://github.com/PRbsas",
   "flairs_attributes"=>{"0"=>{"name"=>"Ruby on Rails", "user_flairs"=>{"experience_level"=>"master"}}}},
 "commit"=>"Update User",
 "id"=>"11”}

Gems

gem 'friendly_id', '~> 5.1.0'
gem 'faker'
gem 'acts_as_votable', '~> 0.11.1'
gem 'dotenv-rails'

Devit uses the FriendlyID gem to make URLs clean and human-readable. Read the Friendly URLs for your Rails App with FriendlyId post where I explain how I implemented it in the app.

The Faker gem is used to create dummy records to seed the database. In app/db/seeds.rb I used it to create Users.

10.times do
  User.create(
    email: Faker::Internet.email,
    name: Faker::Name.name,
    username: Faker::Internet.user_name,
    bio: Faker::Matz.quote,
    github_profile_url: Faker::Internet.url("github.com"),
    avatar_url: Faker::Avatar.image,
    password: Faker::Internet.password(8)
  )
end

The Acts As Votable gem allows a model to vote and be voted on. See my separate post, Acts As Votable gem for Rails Apps, which goes through the process of adding this functionality to devit.

Dotenv is a gem to load environment variables from .env. In the app it stores GitHub’s key and secret to use for authentication.

Next

Some features I want to add are:

  • A User activity page. Where users can see their latest contributions to each community, be it posts, comments or likes/upvotes.
  • Habillity to list all Users with the same Flair, or same Experience Level.
  • A way for users to JOIN Communities and be able to list their communities.