Sorting by values in a loop

Question

I'm trying to store FIFA Games, and set a scoreboard with a ranking system.

I shouldn't use logic in the view, but if I calculate them in the controller, it renders an error that the method user is not specified. When I put it in the loop, however, it recognizes it because the user is the looped item.

The app can already save games and calculate the winner. The app adds winner_id and loser_id to each game. Later in the scoreboard, I count how many current user_id's from the loop match all games' winner_id's and loser_id's. This keeps the database clean. I don't want to keep the wins and losses in the db because when a game is deleted, it shouldn't count as a win or loss anymore.

Controller:

class ScoreboardController < ApplicationController
    def index
        @users = User.all
    end
end

VIEW:

<div class="panel panel-default" style="margin-left: 10px; margin-right:10px">
  <!-- Default panel contents -->
  <div class="panel-heading">Scoreboard</div>

  <!-- Table -->
          <table class="table">
             <thead>
                 <th>#</th>
                 <th>Username</th>
                 <th>Ratio</th>
                 <th>Wins</th>
                 <th>Losses</th>
              </thead>

              <% @users.each do |user|%> 
                 <tbody> 

              <td>
               1 

              </td>

              <td>
                  <%= user.username %>
              </td>

                  <% if (Game.where(:winner_id => user.id).count) == 0 %>

                  <td>Unvalid</td>

                <% elsif (Game.where(:loser_id => user.id).count) == 0 %>

                     <td>Unvalid</td>

                     <% else %>   
                       <% @ratio =  (number_with_precision((((Game.where(:winner_id => user.id).count).to_f) / (Game.where(:loser_id => user.id).count).to_f), precision: 2))  %>

                     <td><%= @ratio %></td>


                     <% end %>

                <td>
                 <%= Game.where(:winner_id => user.id).count %>
              </td>
               <td>
                   <%= Game.where(:loser_id => user.id).count %>
              </td>


                     <% end %>
              </tbody>
          </table>

        </div>

I'd like to put this list in the right order. The list should be ordered by ratio. => the @ratio from the view. Can I do this directly?

In the first td, the current position is shown. It shows 1 for every user. How can I make this 1, 2, 3, ...?

jazzytomato · Accepted Answer · 2016-04-04 12:30:38Z

4

You should add those methods in your User model.

class User < ActiveRecord::Base
  has_many :wins, class_name: 'Game', foreign_key: 'winner_id'
  has_many :losses, class_name: 'Game', foreign_key: 'loser_id'

  def ratio
    wins.count / losses.count.to_f * 100
  end
end

then in the controller :

def index
    @users = User.all.sort_by(&:ratio)
end

and in the view, use the user instance methods directly : <%= user.wins.count %>

answered Apr 4, 2016 at 12:30

jazzytomato

7,2593 gold badges33 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

dp7 · Accepted Answer · 2016-04-04 12:39:30Z

1

You should be doing it the way @ThomasHaratyk has suggested above.

Additional question: in the first td the current position is shown, for now it shows a 1 for every user, how can I make this 1, 2 , 3 , ... ?

<% @users.each_with_index do |user, index|%> 
   <tbody> 
      <td>
          <%= index + 1 %>
       </td>
<% end %>

answered Apr 4, 2016 at 12:39

dp7

6,7491 gold badge23 silver badges38 bronze badges

Collectives™ on Stack Overflow

Sorting by values in a loop

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related