Join table Quantity with cocoon (has_many through) - ruby-on-rails

Question

I didn't find anything related to my problem.
I have these models:
class Meal < ActiveRecord::Base
has_many :meal_ingredients
has_many :ingredients, through: :meal_ingredients
accepts_nested_attributes_for :ingredients, :reject_if => :all_blank, :allow_destroy => true
accepts_nested_attributes_for :meal_ingredients
end
class Ingredient < ActiveRecord::Base
has_many :meal_ingredients
has_many :meals, through: :meal_ingredients
end
class MealIngredient < ActiveRecord::Base
belongs_to :meal
belongs_to :ingredient
end
In the meal_ingredient model I have a quantity column and I want to let the user set this quantity when creating a new meal with many ingredients. To allow that, I used the cocoon gem. And that's when the problem comes: I must set the ingredient_id and the meal_id to build the association with the quantity but I just hit the database when submiting the "Create Meal" buttom.
Part of the solution I thought is creating a fields_forinside the form and set an instance variable in the controller.
But how can I get these ids? I'm stuck.
class MealsController < ApplicationController
before_action :set_meal, only: [:edit, :update, :show]
autocomplete :ingredients, :name
def index
#meals = Meal.order(updated_at: :desc).paginate(:page => params[:page], :per_page => 4)
end
def show
end
def new
#meal = Meal.new
#qtd = MealIngredient.new
end
def create
#meal = Meal.new(meal_params)
#qtd = #meal.ingredients.map{|r| MealIngredient.new(quantity: params[:quantity], ingredient_id: r.id, meal_id: #meal)}
if #meal.save
flash[:success] = "Refeição criada com sucesso!"
redirect_to meals_path
else
render :new
end
end
def edit
end
def update
if #meal.update(meal_params)
flash[:success] = "Your meal was updated succesfully!"
redirect_to meal_path(#meal)
else
render :edit
end
end
private
def meal_params
params.require(:meal).permit(:name, :picture, ingredients_attributes: [:name, :unit, :carb, :prot, :fat])
end
def set_meal
#meal = Meal.find(params[:id])
end
end
This is what I got so far... I don't think the main problem is being caused by cocoon gem. I think it's about concepts...
The params
Parameters: {"utf8"=>"✓", "authenticity_token"=>"dTYOiz8+pwNfwt432qhy7Yuj0hSVksj0bsTzxp8vD6QaupIJueSO1ASDkwiOB92qCiLO33Ke61aUBGbyvGZJfA==", "meal"=>{"name"=>"tests", "ingredients_attributes"=>{"1449471543091"=>{"name"=>"uva", "unit"=>"und", "carb"=>"1", "prot"=>"1", "fat"=>"1", "_destroy"=>"false"}}}, "meal_ingredient"=>{"quantity"=>"14"}, "commit"=>"Create Meal"}
View
_form.html.erb
<div class = "row">
<div class= "col-md-10 col-md-offset-1">
<%= simple_form_for(#meal) do |f| %>
<%= f.error_notification %>
<div class="form-inputs">
<%= f.input :name %>
</div>
<h3>ingredientes</h3>
<div id="ingredients">
<%= f.simple_fields_for :ingredients do |ingredient| %>
<%= render "ingredient_fields", :f => ingredient %>
<% end %>
</div>
<div class="form-actions">
<div><%= link_to_add_association 'adicionar ingrediente', f, :ingredients, :class => "btn btn-default" %></div>
<div><%= f.button :submit, class: "btn btn-success" %></div>
</div>
<% end %>
</div>
</div>
_ingredient_fields.html.erb
<%= render 'shared/errors', obj: #meal %>
<div class = "nested-fields">
<table class= "table">
<thead>
<tr>
<td>
<%= f.label "Nome" %>
</td>
<td>
<%= f.label "Unidade" %>
</td>
<td>
<%= f.label "Carbo" %>
</td>
<td>
<%= f.label "Prot" %>
</td>
<td>
<%= f.label "Gordura" %>
</td>
<td>
<%= f.label "Quantidade" %>
</td>
<td>
<%= f.label "kcal" %>
</td>
</tr>
</thead>
<tbody>
<tr>
<td scope="row" class="col-md-4">
<%= f.text_field :name, required: true, class: "form-control" %>
</td>
<td class="col-md-2">
<%= f.text_field :unit, required: true, class: "form-control" %>
</td>
<td class="col-md-1">
<%= f.text_field :carb, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
</td>
<td class="col-md-1">
<%= f.text_field :prot, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
</td>
<td class="col-md-1">
<%= f.text_field :fat, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
</td>
<td class="col-md-1">
<%= fields_for #qtd do |f| %>
<%= f.hidden_field :ingredient_id %>
<%= f.number_field :quantity, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
<% end %>
</td>
<td class="col-md-1">
</td>
<td class="col-md-1">
<%= link_to_remove_association "remove item", f, :class => "btn btn-danger" %>
</td>
</tr>
</tbody>
</table>
</div>

Answer 1

Following this tutorial and looking at the cocoon's demo app. It was easy to solve my problem, although I actually don't know exactly what I did here the
<%= link_to_add_association 'adicionar ingrediente', f, :meal_ingredients, 'data-association-insertion-node' => "#ingredients ol", 'data-association-insertion-method' => "append", :wrap_object => Proc.new {|quantity| quantity.build_ingredient; quantity }, :class => "btn btn-default" %>
I hate coding this way but this time I just went with the flow very carefully...
If someone has already used cocoon for that purpose and can explain better I - and the community - would appreciate :D
Changes made:
Model
class MealIngredient < ActiveRecord::Base
belongs_to :meal
belongs_to :ingredient
accepts_nested_attributes_for :ingredient, :reject_if => :all_blank
end
Controller
class MealsController < ApplicationController
before_action :set_meal, only: [:edit, :update, :show]
autocomplete :ingredients, :name
def index
#meals = Meal.order(updated_at: :desc).paginate(:page => params[:page], :per_page => 4)
end
def show
end
def new
#meal = Meal.new
end
def create
#meal = Meal.new(meal_params)
if #meal.save
flash[:success] = "Refeição criada com sucesso!"
redirect_to meals_path
else
render :new
end
end
def edit
end
def update
if #meal.update(meal_params)
flash[:success] = "Your meal was updated succesfully!"
redirect_to meal_path(#meal)
else
render :edit
end
end
private
def meal_params
params.require(:meal).permit(:name, :picture, :tcarb, :tprot, :tfat, :tkcal, meal_ingredients_attributes: [:quantity, ingredient_attributes: [:id, :name, :unit, :carb, :prot, :fat, :_destroy]])
end
def set_meal
#meal = Meal.find(params[:id])
end
end
Views
_form.html.erb
<div class = "row">
<div class= "col-md-10 col-md-offset-1">
<%= simple_form_for(#meal) do |f| %>
<%= f.error_notification %>
<div class="form-inputs">
<%= f.input :name %>
</div>
<h3>ingredientes</h3>
<fieldset id="ingredients">
<ol>
<%= f.fields_for :meal_ingredients do |meal_ingredient| %>
<%= render "meal_ingredient_fields", :f => meal_ingredient %>
<% end %>
</ol>
<div class="form-actions">
<div><%= link_to_add_association 'adicionar ingrediente', f, :meal_ingredients, 'data-association-insertion-node' => "#ingredients ol", 'data-association-insertion-method' => "append", :wrap_object => Proc.new {|quantity| quantity.build_ingredient; quantity }, :class => "btn btn-default" %></div>
</div>
</fieldset>
<div class="form-actions">
<div><%= f.button :submit, class: "btn btn-success" %></div>
</div>
<% end %>
</div>
</div>
_meal_ingredient_fields.html.erb
<div class = "nested-fields">
<table class= "table">
<thead>
<tr>
<td>
<%= f.label "Nome" %>
</td>
<td>
<%= f.label "Unidade" %>
</td>
<td>
<%= f.label "Carbo" %>
</td>
<td>
<%= f.label "Prot" %>
</td>
<td>
<%= f.label "Gordura" %>
</td>
<td>
<%= f.label "Quantidade" %>
</td>
<td>
<%= f.label "kcal" %>
</td>
</tr>
</thead>
<tbody>
<tr>
<%= f.fields_for :ingredient do |fi| %>
<td scope="row" class="col-md-4">
<%= fi.text_field :name, required: true, class: "form-control" %>
</td>
<td class="col-md-2">
<%= fi.text_field :unit, required: true, class: "form-control" %>
</td>
<td class="col-md-1">
<%= fi.text_field :carb, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
</td>
<td class="col-md-1">
<%= fi.text_field :prot, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
</td>
<td class="col-md-1">
<%= fi.text_field :fat, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
</td>
<% end %>
<td class="col-md-1">
<%= f.number_field :quantity, required: true, :pattern => '^\d+(\.\d+)*$', title: "Apenas números separados por pontos", class: "form-control" %>
</td>
<td class="col-md-1">
</td>
<td class="col-md-1">
<%= link_to_remove_association "remove item", f, :class => "btn btn-danger" %>
</td>
</tr>
</tbody>
</table>
</div>

Answer 2

I used cocoon also, and had some troubles setting it up. I think you have to realiaze that Rails is smarter then you think. You can easily just call save on the parameter string. Just make sure the parameters are all accepted. You will also need :id for ingredients_attributes for instance (and :_destroy, if you allow deletion as well). Oh, and loose the nested_attributes for your join table as well.
I think something like this should work:
def new
#meal = Meal.new
end
def create
#meal = Meal.new(meal_params)
if #meal.save
flash[:success] = "Refeição criada com sucesso!"
redirect_to meals_path
else
render :new
end
end
private
def meal_params
params.require(:meal).permit(:name, :picture, ingredients_attributes: [:id, :name, :unit, :carb, :prot, :fat, :_destroy])
end
If it doensn't, please post your views that contain the main form and the partials.