Guess correct name for namespaced associations (#2235)

Fixes #1978

This includes the namespace of the associated class. If the associated class
is `System::Build`, the previous code would tell us that the name was `Build`.
This code gets the right name.

lib/administrate/field/associative.rb

@@ -12,7 +12,7 @@ def self.associated_class(resource_class, attr)
       end
 
       def self.associated_class_name(resource_class, attr)
-        reflection(resource_class, attr).class_name
+        associated_class(resource_class, attr).name
       end
 
       def self.reflection(resource_class, attr)

spec/example_app/app/controllers/admin/blog/tags_controller.rb

@@ -0,0 +1,6 @@
+module Admin
+  module Blog
+    class TagsController < Admin::ApplicationController
+    end
+  end
+end

spec/example_app/app/dashboards/blog/post_dashboard.rb

@@ -9,6 +9,7 @@ class PostDashboard < Administrate::BaseDashboard
       title: Field::String,
       published_at: Field::DateTime,
       body: Field::Text,
+      tags: Field::HasMany,
     }
 
     READ_ONLY_ATTRIBUTES = [
@@ -20,6 +21,7 @@ class PostDashboard < Administrate::BaseDashboard
     COLLECTION_ATTRIBUTES = [
       :id,
       :title,
+      :tags,
       :published_at,
     ]
 

spec/example_app/app/dashboards/blog/tag_dashboard.rb

@@ -0,0 +1,31 @@
+require "administrate/base_dashboard"
+
+module Blog
+  class TagDashboard < Administrate::BaseDashboard
+    ATTRIBUTE_TYPES = {
+      id: Field::Number,
+      name: Field::String,
+      created_at: Field::DateTime,
+      updated_at: Field::DateTime,
+      posts: Field::HasMany,
+    }.freeze
+
+    COLLECTION_ATTRIBUTES = %i[
+      id
+      name
+      posts
+      created_at
+    ].freeze
+
+    FORM_ATTRIBUTES = %i[
+      name
+      posts
+    ].freeze
+
+    SHOW_PAGE_ATTRIBUTES = COLLECTION_ATTRIBUTES
+
+    def display_resource(resource)
+      resource.name
+    end
+  end
+end

spec/example_app/app/models/blog/post.rb

@@ -1,5 +1,7 @@
 module Blog
   class Post < ApplicationRecord
+    has_and_belongs_to_many :tags
+
     validates :title, :body, presence: true
   end
 end

spec/example_app/app/models/blog/tag.rb

@@ -0,0 +1,7 @@
+module Blog
+  class Tag < ApplicationRecord
+    has_and_belongs_to_many :posts
+
+    validates :name, presence: true
+  end
+end

spec/example_app/app/policies/blog/tag_policy.rb

@@ -0,0 +1,4 @@
+module Blog
+  class TagPolicy < ApplicationPolicy
+  end
+end

spec/example_app/config/routes.rb

@@ -16,6 +16,7 @@
 
     namespace :blog do
       resources :posts
+      resources :tags
     end
 
     resources :stats, only: [:index]

spec/example_app/db/migrate/20220804132651_create_blog_tags.rb

@@ -0,0 +1,9 @@
+class CreateBlogTags < ActiveRecord::Migration[6.1]
+  def change
+    create_table :blog_tags do |t|
+      t.string :name
+
+      t.timestamps
+    end
+  end
+end

spec/example_app/db/migrate/20220804133503_create_blog_posts_tags.rb

@@ -0,0 +1,9 @@
+class CreateBlogPostsTags < ActiveRecord::Migration[6.1]
+  def change
+    create_table :blog_posts_tags do |t|
+      t.belongs_to :post
+      t.belongs_to :tag
+      t.timestamps
+    end
+  end
+end

spec/example_app/db/schema.rb

@@ -2,15 +2,15 @@
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
 #
-# This file is the source Rails uses to define your schema when running `rails
-# db:schema:load`. When creating a new database, `rails db:schema:load` tends to
+# This file is the source Rails uses to define your schema when running `bin/rails
+# db:schema:load`. When creating a new database, `bin/rails db:schema:load` tends to
 # be faster and is potentially less error prone than running all of your
 # migrations from scratch. Old migrations may fail to apply correctly if those
 # migrations use external dependencies or application code.
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_07_14_081950) do
+ActiveRecord::Schema.define(version: 2022_08_04_133503) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -23,6 +23,21 @@
     t.datetime "updated_at", null: false
   end
 
+  create_table "blog_posts_tags", force: :cascade do |t|
+    t.bigint "post_id"
+    t.bigint "tag_id"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["post_id"], name: "index_blog_posts_tags_on_post_id"
+    t.index ["tag_id"], name: "index_blog_posts_tags_on_tag_id"
+  end
+
+  create_table "blog_tags", force: :cascade do |t|
+    t.string "name"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+  end
+
   create_table "countries", id: :serial, force: :cascade do |t|
     t.string "code", null: false
     t.string "name"

spec/example_app/db/seeds.rb

@@ -59,19 +59,25 @@
 
 Product.find_each do |p|
   Page.create!(
-    title: "Something about #{p.name}",
+    title: "Rules of #{p.name}",
     body: Faker::Lorem.paragraph,
     product: p,
   )
-  Page.create!(
-    title: "The secrets of the game #{p.name}",
+end
+
+tag_secrets = Blog::Tag.create!(name: "secrets")
+tag_recommendations = Blog::Tag.create!(name: "recommendations")
+
+Product.find_each do |p|
+  Blog::Post.create!(
+    title: "The secrets of #{p.name}",
     body: Faker::Lorem.paragraph,
-    product: p,
+    tags: [tag_secrets],
   )
-  Page.create!(
-    title: "If you liked #{p.name}, you will love these games",
+  Blog::Post.create!(
+    title: "If you liked #{p.name}, you will love these products",
     body: Faker::Lorem.paragraph,
-    product: p,
+    tags: [tag_recommendations],
   )
 end
 

spec/factories.rb

@@ -61,6 +61,10 @@
     body { "Empty" }
   end
 
+  factory :blog_tag, class: "Blog::Tag" do
+    name { Faker::NatoPhoneticAlphabet.code_word.downcase }
+  end
+
   factory :series do
     sequence(:name) { |n| "Series #{n}" }
   end

spec/features/associations_spec.rb

@@ -0,0 +1,13 @@
+require "rails_helper"
+
+describe "Associations" do
+  it "can associate to namespaced models on dashboards" do
+    post = create(:blog_post)
+    tag = create(:blog_tag, name: "foobarisms")
+    post.tags << tag
+
+    visit admin_blog_post_url(post)
+
+    expect(page).to have_css(".cell-data", text: "foobarisms")
+  end
+end