Rails 4 includes multiple has_many and belongs_to index.html.erb - ruby-on-rails-4

Question

How would I handle a belong_to with the following include. Instead of displaying the product_colour_id id like to show the associated colour (Update:Solved this part below). The product_colour_id is in the Product table and matches the corresponding Product_colour id.
Its the case of two or more has_many associations that i cant work out. Can it be done?
app/controller/home_controller.rb
class HomeController < ApplicationController
def index
products = Product.last(5)
product_ids = products.map(&:id)
#product_colour_ids = products.map(&:product_colour_id)
#allproduct_colours = ProductColour.all
#product_colour_map = ProductColour.find(#product_colour_ids)
#product_images = Product.includes(:product_images)
.where(product_images: {product_id: product_ids, :default_image => true})
end
end
/app/views/home/index.html.erb
<% #product_images.each do |pd| %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
<% end %> </div>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p> <%= pd.product_colour_id %></p>
</div>
<% end %>
<% end %>
</div>
I'm having difficulty finding examples of multiple has_many includes. I assume there is a very straight forward pattern to it but cant work it out from apidock or api.rubyonrails.org. The problem i'm having is adding the Supply_company which is a has_many :through relationship to the one I already have with the product_image include.
Thankyou in advance for your advise
Update I have worked out how to display the belongs_to... feeling a little dumb on that as it was very easy just needed some time to think
<% pd.product_images.each do |pd| %>
<p> <%= pd.product_colour.product_colour %></p>
<% end %>
/app/models/product.rb
class Product < ActiveRecord::Base
belongs_to :product_type
belongs_to :product_category
belongs_to :product_colour
belongs_to :product_size
has_many :product_supply_companies, :foreign_key => 'product_id'
accepts_nested_attributes_for :product_supply_companies, :allow_destroy => true
has_many :supply_companies, :through => :product_supply_companies
accepts_nested_attributes_for :supply_companies
has_many :product_images, dependent: :destroy, :foreign_key => 'product_id'
accepts_nested_attributes_for :product_images, :allow_destroy => true
end
app/models/product_supply_company.rb
class ProductSupplyCompany < ActiveRecord::Base
belongs_to :product
belongs_to :supply_company
# accepts_nested_attributes_for :supply_company
# accepts_nested_attributes_for :product
end
app/models/supply_company.rb
class SupplyCompany < ActiveRecord::Base
has_many :products, :through => :product_supply_companies
has_many :product_supply_companies, :foreign_key => 'supply_company_id'
accepts_nested_attributes_for :products
accepts_nested_attributes_for :product_supply_companies, :allow_destroy => true
end
app/models/product_colour.rb
class ProductColour < ActiveRecord::Base
has_many :products
end
Database Schema
create_table "product_categories", force: true do |t|
t.string "product_category"
t.string "product_category_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_colours", force: true do |t|
t.string "product_colour"
t.string "product_colour_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_images", force: true do |t|
t.integer "product_id", null: false
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "product_image_file_name"
t.string "product_image_content_type"
t.integer "product_image_file_size"
t.datetime "product_image_updated_at"
t.boolean "default_image"
end
create_table "product_sizes", force: true do |t|
t.string "product_size"
t.string "product_size_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_supply_companies", force: true do |t|
t.integer "product_id"
t.integer "supply_company_id"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_types", force: true do |t|
t.string "product_type"
t.string "product_type_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "products", force: true do |t|
t.string "product_name"
t.text "product_description"
t.integer "product_type_id"
t.integer "product_category_id"
t.string "product_colour_id"
t.integer "product_size_id"
t.datetime "created_at"
t.datetime "updated_at"
end

Answer 1

#products = Product.includes(:product_images, :colour, :supply_companies)
.where(product_images: {product_id: product_ids, :default_image => true})
.select('products.*, product_colours.product_colour')
this the query with all associations.
index.html.erb
<% #products.each do |pd| %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
</div>
<% end %>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p><%= pd.product_colour %></p>
</div>
<% end %>
<% end %>
Product.rb
belongs_to :colour, class: 'ProductColor', foreign_key: 'product_colour_id'

Answer 2

For those that follow. User123 gave me some ideas that finally provided a solution. I had been over thinking the problem mostly.
app/controller/home_controller.rb
class HomeController < ApplicationController
def index
products = Product.last(5) ## find last five products
product_ids = products.map(&:id) ## map their ids so I can retrieve
images with matching id's
## create array of products with corresponding default_images.
## Not necessary to include has_many, has_many :through or
## belongs_to as they can be added directly on index.html.erb page
#products = Product.includes(:product_images)
.where(product_images: {product_id: product_ids, :default_image => true}).last(5)
end
end
/app/views/home/index.html.erb
<% #products.each do |pd| #1st level directly access product_attributes %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| # 2nd access has_many with
foreign key in different table %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
</div>
<% end %>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p><%= pd.product_colour.product_colour #first level access
belong_to relationship attributes %></p>
<p><% pd.supply_companies.each do |sc| # 2nd level again to
access has_many :through relationship only done again for
layout purposes. %></p>
<%= sc.company_name %>
<% end %>
</div>
<% end %>
<% end %>