Make widget cards polymorphic

So now we'll be able to add them to other sections.

We're also adding a `dependent: :destroy` relation to models having
cards since it doesn't make sense to have cards around when their page
has been destroyed.

app/models/concerns/cardable.rb

@@ -0,0 +1,7 @@
+module Cardable
+  extend ActiveSupport::Concern
+
+  included do
+    has_many :cards, class_name: "Widget::Card", as: :cardable, dependent: :destroy
+  end
+end

app/models/site_customization/page.rb

@@ -1,10 +1,6 @@
 class SiteCustomization::Page < ApplicationRecord
   VALID_STATUSES = %w[draft published].freeze
-  has_many :cards,
+  include Cardable
-    class_name:  "Widget::Card",
-    foreign_key: "site_customization_page_id",
-    inverse_of:  :page
-
   translates :title,       touch: true
   translates :subtitle,    touch: true
   translates :content,     touch: true

app/models/widget/card.rb

@@ -1,9 +1,6 @@
 class Widget::Card < ApplicationRecord
   include Imageable
-  belongs_to :page,
+  belongs_to :cardable, polymorphic: true
-    class_name:  "SiteCustomization::Page",
-    foreign_key: "site_customization_page_id",
-    inverse_of:  :cards
 
   translates :label,       touch: true
   translates :title,       touch: true
@@ -18,6 +15,6 @@ class Widget::Card < ApplicationRecord
   end
 
   def self.body
-    where(header: false, site_customization_page_id: nil).order(:created_at)
+    where(header: false, cardable_id: nil).order(:created_at)
   end
 end

config/routes/admin.rb

@@ -271,7 +271,7 @@ resolve "Audit" do |audit|
 end
 
 resolve "Widget::Card" do |card, options|
-  [*resource_hierarchy_for(card.page), card]
+  [*resource_hierarchy_for(card.cardable), card]
 end
 
 resolve "Budget::Group" do |group, options|

db/migrate/20210106132909_make_cards_polymorphic.rb

@@ -0,0 +1,8 @@
+class MakeCardsPolymorphic < ActiveRecord::Migration[5.2]
+  def change
+    change_table :widget_cards do |t|
+      t.rename :site_customization_page_id, :cardable_id
+      t.string :cardable_type, default: "SiteCustomization::Page"
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_12_16_132642) do
+ActiveRecord::Schema.define(version: 2021_01_06_132909) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_trgm"
@@ -1647,9 +1647,10 @@ ActiveRecord::Schema.define(version: 2020_12_16_132642) do
     t.boolean "header", default: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.integer "site_customization_page_id"
+    t.integer "cardable_id"
     t.integer "columns", default: 4
-    t.index ["site_customization_page_id"], name: "index_widget_cards_on_site_customization_page_id"
+    t.string "cardable_type", default: "SiteCustomization::Page"
+    t.index ["cardable_id"], name: "index_widget_cards_on_cardable_id"
   end
 
   create_table "widget_feeds", id: :serial, force: :cascade do |t|

spec/models/widget/card_spec.rb

@@ -34,7 +34,7 @@ describe Widget::Card do
       header = create(:widget_card, header: true)
       card1 = create(:widget_card, header: false)
       card2 = create(:widget_card, header: false)
-      page_card = create(:widget_card, header: false, page: create(:site_customization_page))
+      page_card = create(:widget_card, header: false, cardable: create(:site_customization_page))
 
       expect(Widget::Card.body).to match_array [card1, card2]
       expect(Widget::Card.body).not_to include(header)

spec/routing/polymorphic_routes_spec.rb

@@ -172,7 +172,7 @@ describe "Polymorphic routes" do
 
     it "routes site customization page widget cards" do
       page = create(:site_customization_page)
-      card = create(:widget_card, page: page)
+      card = create(:widget_card, cardable: page)
 
       expect(admin_polymorphic_path(card)).to eq admin_site_customization_page_widget_card_path(page, card)
     end

spec/system/admin/widgets/cards_spec.rb

@@ -175,9 +175,9 @@ describe "Cards", :admin do
       end
 
       scenario "Show" do
-        card_1 = create(:widget_card, page: custom_page, title: "Card large", columns: 8)
+        card_1 = create(:widget_card, cardable: custom_page, title: "Card large", columns: 8)
-        card_2 = create(:widget_card, page: custom_page, title: "Card medium", columns: 4)
+        card_2 = create(:widget_card, cardable: custom_page, title: "Card medium", columns: 4)
-        card_3 = create(:widget_card, page: custom_page, title: "Card small", columns: 2)
+        card_3 = create(:widget_card, cardable: custom_page, title: "Card small", columns: 2)
 
         visit custom_page.url
 
@@ -189,8 +189,8 @@ describe "Cards", :admin do
       end
 
       scenario "Show label only if it is present" do
-        card_1 = create(:widget_card, page: custom_page, title: "Card one", label: "My label")
+        card_1 = create(:widget_card, cardable: custom_page, title: "Card one", label: "My label")
-        card_2 = create(:widget_card, page: custom_page, title: "Card two")
+        card_2 = create(:widget_card, cardable: custom_page, title: "Card two")
 
         visit custom_page.url
 
@@ -204,7 +204,7 @@ describe "Cards", :admin do
       end
 
       scenario "Edit", :js do
-        create(:widget_card, page: custom_page, title: "Original title")
+        create(:widget_card, cardable: custom_page, title: "Original title")
 
         visit admin_site_customization_page_widget_cards_path(custom_page)
 
@@ -227,7 +227,7 @@ describe "Cards", :admin do
       end
 
       scenario "Destroy", :js do
-        create(:widget_card, page: custom_page, title: "Card title")
+        create(:widget_card, cardable: custom_page, title: "Card title")
 
         visit admin_site_customization_page_widget_cards_path(custom_page)
 

spec/system/site_customization/custom_pages_spec.rb

@@ -104,7 +104,7 @@ describe "Custom Pages" do
 
       scenario "Show widget cards for that page" do
         custom_page = create(:site_customization_page, :published)
-        create(:widget_card, page: custom_page, title: "Card Highlights")
+        create(:widget_card, cardable: custom_page, title: "Card Highlights")
 
         visit custom_page.url