undefined method `image' for #<Array> when using group_by - ruby-on-rails

Question

Hi can anyone point me to the right direction? I´m trying to show images on views/pages/index.html.erb the images are uploaded on views/products/new.html.erbthrough the _form.html.erbpartial. Each product/picture then belongs to a category which I can select in the _navbar.html.erb and is then directed to the views/categories/show.html.erbto see pictures of each product in that category and so on.
That is all working fine
But now I want to display the last added picture in each category on the views/pages/index.html.erb and I´m always getting this error : undefined method 'image' for #<Array:0x007f8d1fb19ff0>
I´m pretty lost at the moment, and hopefully someone can guide me to the right path.
My code id like this:
pages_controller.rb
class PagesController < ApplicationController
def index
#products = Product.all.order(created_at: :desc).group_by(&:category_id)
end
def about
end
def location
end
def stockists
end
end
views/pages/index.html.erb
<% #products.each do |product| %>
<div class="col-lg-3 col-sm-6 col-xs-12 center-block " >
<%= image_tag product.image.url(:medium) %>
<p><%= product.name %></p>
<p><%= product.category.name %></p>
<% end %>
</div>
And then I have, the products.rb and category.rb
product.rb
class Product < ActiveRecord::Base
mount_uploader :image, ImageUploader
validates_presence_of :name, :price
validates_numericality_of :price
belongs_to :category
end
category.rb
class Category < ActiveRecord::Base
has_many :products
end
this as part of the schema.rb
create_table "products", force: :cascade do |t|
t.string "name"
t.string "description"
t.float "price"
t.string "image"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "category_id", default: 1
end
add_index "products", ["category_id"], name: "index_products_on_category_id", using: :btree
and in the end there is this part
add_foreign_key "order_items", "orders", on_delete: :cascade
add_foreign_key "order_items", "products"
add_foreign_key "orders", "users", on_delete: :cascade
add_foreign_key "products", "categories"
end

Answer 1

You are using group_by in the controller, an enumerable method that returns a hash of Product arrays keyed by category_id.
#product = {
:category1 => [#<Product category_id=1>, #<Product category_id=1>, ...],
:category2 => [#<Product category_id=2>, #<Product category_id=2>, ...]
}
When you loop through #products in the view, you are looping through a hash where each iteration is passing an array.
The product variable does not contain a product, but an array of products.
<% #products.each do |product| %> # product is type Array!
<%= image_tag product.image.url(:medium) %> # Array.image throws an error!
<% end %>
You must create an outer loop to step through the hash.
<% #products.each do |category, products| %>
<% products.each do |product| %>
# do stuff
<% end %>
<% end %>