CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-4nested-attributeshas-many-through
Neil
Neil

Reputation: 872

Editing join table values in rails nested attributes

Been stuck on this one for a while so I figured I'd throw it out there.

I have two models and a join model:

class Container < ActiveRecord::Base
  has_many :theme_containers
  has_many :themes, :through => :theme_containers
end

class Theme < ActiveRecord::Base
  has_many :theme_containers
  has_many :containers, :through => :theme_containers
end

class ThemeContainer < ActiveRecord::Base
  belongs_to :container
  belongs_to :theme
end

Grand. I know this association is working because in the console, when I type Theme.first.containers and Theme.first.theme_containers I get the models I expect (I've created the theme_container instances manually for the time being).

The issue is that in my form for theme I want to be able to update attributes on the join data, (theme_containers).

Here's a simplified version of my form:

<%= form_for(@theme) do |f| %>
  <%= f.fields_for :theme_containers do |builder| %>
    <%= render 'theme_container_fields', f: builder %>
  <% end %>
<% end %>

When I run this, the container_fields partial is only rendered once and the builder object seems to be looking at the original @theme object. Is there something glaringly obviously wrong with my approach here? Is what I'm trying to do possible?

Also, I'm running rails 4 so I'm not using accepts_nested_attributes_for, and I have my strong parameters set up. I don't believe that should affect my specific issue but just throwing that out there too.

Thanks!

Upvotes: 3

Views: 682

Answers (1)

Obito Uchiha
Obito Uchiha

Reputation: 41

What i would do is the following:

class Theme < ActiveRecord::Base
  has_many :theme_containers
  has_many :containers, :through => :theme_containers

  accepts_nested_attributes_for :theme_containers
end

and in your ThemeController:

def new
  @theme = Theme.new
  Container.all.each do |container|
    @theme.theme_container.build(container_id: container.id)
  end
end

Upvotes: 1

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