Sorting posts based on the most liked in Rails

Question

I am trying to have two tabs, one for the most recent posts and the other is for the most liked posts. However, I am really stuck of how to get my post sorted by the most liked(voted). I did use acts_as_votable gem to get the voting system part into the website. I am new to Rails, let me know if what more details do you need to help out,thanks.

Answer 1

You should enable Caching. These columns will automatically be updated after each vote.

Create new migration rails g migration add_cached_votes_to_posts and add below code:

class AddCachedVotesToPosts < ActiveRecord::Migration
  def self.up
    add_column :posts, :cached_votes_total, :integer, :default => 0
    add_column :posts, :cached_votes_score, :integer, :default => 0
    add_column :posts, :cached_votes_up, :integer, :default => 0
    add_column :posts, :cached_votes_down, :integer, :default => 0
    add_column :posts, :cached_weighted_score, :integer, :default => 0
    add_column :posts, :cached_weighted_total, :integer, :default => 0
    add_column :posts, :cached_weighted_average, :float, :default => 0.0
    add_index  :posts, :cached_votes_total
    add_index  :posts, :cached_votes_score
    add_index  :posts, :cached_votes_up
    add_index  :posts, :cached_votes_down
    add_index  :posts, :cached_weighted_score
    add_index  :posts, :cached_weighted_total
    add_index  :posts, :cached_weighted_average

    # Uncomment this line to force caching of existing votes
    # Post.find_each(&:update_cached_votes)
  end

  def self.down
    remove_column :posts, :cached_votes_total
    remove_column :posts, :cached_votes_score
    remove_column :posts, :cached_votes_up
    remove_column :posts, :cached_votes_down
    remove_column :posts, :cached_weighted_score
    remove_column :posts, :cached_weighted_total
    remove_column :posts, :cached_weighted_average
  end
end

Run migration command rake db:migrate

And use the cached column for ordering:

Post.order(cached_votes_score: :desc)