Show object ids in scaffold pages when displaying referenced objects

Resolve Issue#29200

When scaffolding a model that references another model the
generated show and index html pages display the object directly
on the page. Basically, it just shows a memory address. That is
not very helpful. In this commit we show the object's id rather
than the memory address.

This updates the scaffold templates and the json builder files.

4 files changed, 20 insertions, 5 deletions

diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 1a415449d1..e581766c69 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,8 @@
+*  Use Ids instead of memory addresses when displaying references in scaffold views
+    Fixes #29200.
+
+    *Rasesh Patel*
+
 *   Adds support for multiple databases to `rails db:migrate:status`.
     Subtasks are also added to get the status of individual databases (eg. `rails db:migrate:status:animals`).
 
diff --git a/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb.tt b/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb.tt
index e1ede7c713..2cf4e5c9d0 100644
--- a/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb.tt
+++ b/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb.tt
@@ -16,7 +16,7 @@
     <%% @<%= plural_table_name %>.each do |<%= singular_table_name %>| %>
       <tr>
 <% attributes.reject(&:password_digest?).each do |attribute| -%>
-        <td><%%= <%= singular_table_name %>.<%= attribute.name %> %></td>
+        <td><%%= <%= singular_table_name %>.<%= attribute.column_name %> %></td>
 <% end -%>
         <td><%%= link_to 'Show', <%= model_resource_name %> %></td>
         <td><%%= link_to 'Edit', edit_<%= singular_route_name %>_path(<%= singular_table_name %>) %></td>
diff --git a/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb.tt b/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb.tt
index 5e634153be..7deba07926 100644
--- a/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb.tt
+++ b/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb.tt
@@ -3,7 +3,7 @@
 <% attributes.reject(&:password_digest?).each do |attribute| -%>
 <p>
   <strong><%= attribute.human_name %>:</strong>
-  <%%= @<%= singular_table_name %>.<%= attribute.name %> %>
+  <%%= @<%= singular_table_name %>.<%= attribute.column_name %> %>
 </p>
 
 <% end -%>
diff --git a/railties/test/generators/scaffold_generator_test.rb b/railties/test/generators/scaffold_generator_test.rb
index 21b5013484..3cffdddd38 100644
--- a/railties/test/generators/scaffold_generator_test.rb
+++ b/railties/test/generators/scaffold_generator_test.rb
@@ -435,8 +435,8 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_scaffold_generator_belongs_to
-    run_generator ["account", "name", "currency:belongs_to"]
+  def test_scaffold_generator_belongs_to_and_references
+    run_generator ["account", "name", "currency:belongs_to", "user:references"]
 
     assert_file "app/models/account.rb", /belongs_to :currency/
 
@@ -449,7 +449,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
 
     assert_file "app/controllers/accounts_controller.rb" do |content|
       assert_instance_method :account_params, content do |m|
-        assert_match(/permit\(:name, :currency_id\)/, m)
+        assert_match(/permit\(:name, :currency_id, :user_id\)/, m)
       end
     end
 
@@ -457,6 +457,16 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
       assert_match(/^\W{4}<%= form\.text_field :name %>/, content)
       assert_match(/^\W{4}<%= form\.text_field :currency_id %>/, content)
     end
+
+    assert_file "app/views/accounts/index.html.erb" do |content|
+      assert_match(/^\W{8}<td><%= account\.name %><\/td>/, content)
+      assert_match(/^\W{8}<td><%= account\.user_id %><\/td>/, content)
+    end
+
+    assert_file "app/views/accounts/show.html.erb" do |content|
+      assert_match(/^\W{2}<%= @account\.name %>/, content)
+      assert_match(/^\W{2}<%= @account\.user_id %>/, content)
+    end
   end
 
   def test_scaffold_generator_database