Provide another model's fields for nested form in Rails - ruby-on-rails

Question

I have a Rails app I'm building to manage a fantasy tennis bracket game.
Here are my models.
The game where the players will submit their picks:
class Game < ActiveRecord::Base
belongs_to :user
belongs_to :event
has_many :picks, dependent: :destroy
accepts_nested_attributes_for :picks
The matches where I match up two tennis players:
class Match < ActiveRecord::Base
belongs_to :event
belongs_to :player_1, class_name: "Player"
belongs_to :player_2, class_name: "Player"
has_many :picks, dependent: :destroy
The pick model.
class Pick < ActiveRecord::Base
belongs_to :game
belongs_to :match
I am using a nested form inside of another form which I have working.
<%= form_for(#game) do |f| %>
<% if #game.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#game.errors.count, "error") %> prohibited this game from being saved:</h2>
<ul>
<% #game.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :user_id %><br>
<%= f.collection_select(:user_id, User.all, :id, :name) %>
</div>
<div class="field">
<%= f.label :event_id %><br>
<%= f.collection_select(:event_id, Event.all, :id, :title) %>
</div>
<div class="field">
<%= f.label :score %><br>
<%= f.number_field :score %>
</div>
<% #matches.each do |g| %>
<%= f.fields_for :picks do |ff| %>
<fieldset>
<%= ff.label :match_id %>
<%= ff.text_field :match_id %>
<%= ff.label :winner, "Select the Winner" %>
<%= ff.text_field :winner %>
</fieldset>
<br>
<% end %>
<% end %>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
I would like to use the fields from the Match model to populate the fields on the Pick model. For example, the Match has two players, I want to be able to pull the player's names into the :picks form, and will probably use an f.select on them.
I have some player data on the Match model I want to dynamically pull into the Pick model. Can't figure out how to query the database and get the field attributes to be accessed by the Pick nested form. Any help would be appreciated.

Answer 1

Here's what I'd do.
Get rid of "games"
Make "picks" the model to store "game" information
I think the major issue you have currently is the Game and Pick models are trying to do the same thing.
#app/models/match.rb
class Match < ActiveRecord::Base
# columns id | event_id | name | player_1 | player_2
belongs_to :event
has_many :picks
belongs_to :player_1, class_name: "Player", primary_key: :player_1
belongs_to :player_2, class_name: "Player", primary_key: :player_2
def players
[player_1, player_2]
end
end
#app/models/pick.rb
class Pick < ActiveRecord::Base
# columns id | user_id | match | winner | etc
belongs_to :user
belongs_to :match, primary_key: :match
has_one :winner, primary_key: :winner
end
This means you'll be able to do the following:
#app/views/picks/new.html.erb
<% #matches.each do |match| %>
<%= match.name %>
<%= form_for match.picks.new do |f| %>
<%= f.hidden_field :match, match.id %>
<%= f.collection_select :winner, match.players, :id, :name, prompt: "Who will win?" %>
<%= f.submit %>
<% end %>
<% end %>
#app/controllers/picks_controller.rb
class PicksController < ActionController::Base
def new
#matches = Match.all
end
def create
#pick = Pick.new pick_params
#pick.save
end
private
def pick_params
params.require(:pick).permit(:match, :winner).merge(user_id: current_user)
end
end
This will give you the ability to "pick" the players in the most simple & extensible way.