Call controller from the view of another controller - ruby-on-rails

Question

i have a restaurant controller, and in the show method i render a form of another controller (dishes)
#new.html.erb (from dishes controller)
<%= render 'dishes/dish_form' %>
#show.html.erb (from restaurant controller)
<%= render template: 'dishes/new' %>
and this is the form:
<%= form_for #dish, :url => { :controller => "dishes", action_name => "create" } do |f| %>
<div class="field">
<%= f.label :dish_name %>
<%= f.text_field :name %>
</div>
<div class="field">
<%= f.label :description %>
<%= f.text_field :description %>
</div>
<div class="field">
<%= f.label :image %>
<%= f.file_field :avatar %>
</div>
<div class="actions">
<%= f.submit 'Add new dish' %>
</div>
<% end %>
but when i try so add a dish, i have this error
this is my dishes controller:
def new
#dish = Dish.new
end
def create
#dish = Dish.new(dish_params)
respond_to do |format|
if #dish.save
format.html { redirect_to #restaurant, notice: 'dish was successfully created.' }
format.json { render action: 'show', status: :created, location: :restaurant }
else
format.html { render action: 'show', location: :restaurant }
format.json { render json: #restaurant.errors, status: :unprocessable_entity }
end
end
end
private
def dish_params
params.require(:dish).permit(:avatar, :name, :description)
end
and this are my models:
class Restaurant < ApplicationRecord
has_many :dish, inverse_of: :restaurant
accepts_nested_attributes_for :dish
end
class Dish < ApplicationRecord
belongs_to :restaurant
end
im learning rails so maybe is a dumb error but im stuck

Answer 1

you should try to this to the controller action where the form is rendered
#dish = Dish.new
as you directly call the 'create' action rails is missing the instance variable Dish.new. Therefore the error message. Normally rails works like this:
def new
#dish = Dish.new
end
and than you call the create action on 'submit'.
However, as it looks like you call the form from the #show action just add this code there and you will be fine. May be not the best solution but it will work like that. Add to #show
#dish = Dish.new
Sorry mate. Yes #dish is correct and not :dishes.

Answer 2

OK.
My latest guess is that you want the restaurants to be able to create many dishes.
So you should set up your models accordingly:
#restaurants_model
has_many :dishes
#dishes_model
belongs_to :restaurant
next is that you add a column called restaurant_id to your dishes table
t.string :restaurant_id
than in your restaurant controller #show
def show
end
if you use the routes as normal, e.g.
resources :restaurants
resources :dishes
the show action of the restaurant controller should give you a url that looks like this: localhost:3000/restaurants/1
where the 1 is the id of the restaurant.
This id you want to save to the dish by adding a hidden field
=f.hidden_field :restaurant_id, value: #restaurant.id
you need to permit the restaurant_id in the dishes controller params, e.g. dish_params. Just add
:restaurant_id
and it should be fine. This way the id will be saved to the dishes table and you can later call it from there.
This gives you the chance to call #restaurant.dishes which will show all dishes of that restaurant.
If you just want to redirect back you can use redirect :back
Otherwise, you can try to integrate a helper to get the right restaurant using the hidden restaurant_id field