Document+test that frame layout can be overridden

hotwired · Feb 7, 2023 · c975ede · c975ede
1 parent 5abe3c7
commit c975ede
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Showing 3 changed files with 35 additions and 5 deletions.
diff --git a/app/controllers/turbo/frames/frame_request.rb b/app/controllers/turbo/frames/frame_request.rb
@@ -1,18 +1,21 @@
 # Turbo frame requests are requests made from within a turbo frame with the intention of replacing the content of just
 # that frame, not the whole page. They are automatically tagged as such by the Turbo Frame JavaScript, which adds a
 # <tt>Turbo-Frame</tt> header to the request.
-#
+# 
 # When that header is detected by the controller, we substitute our own minimal layout in place of the
 # application-supplied layout (since we're only working on an in-page frame, thus can skip the weight of the layout). We
 # use a minimal layout, rather than avoid the layout entirely, so that it's still possible to render content into the
 # <tt>head<tt>.
-#
+# 
 # Accordingly, we ensure that the etag for the page is changed, such that a cache for a minimal-layout request isn't
 # served on a normal request and vice versa.
-#
+# 
 # This is merely a rendering optimization. Everything would still work just fine if we rendered everything including the
-# full layout.  Turbo Frames knows how to fish out the relevant frame regardless.
-#
+# full layout. Turbo Frames knows how to fish out the relevant frame regardless.
+# 
+# The layout used is <tt>turbo_rails/frame.html.erb</tt>. If there's a need to customize this layout, an application can
+# supply its own (such as <tt>app/views/layouts/turbo_rails/frame.html.erb</tt>) which will be used instead.
+# 
 # This module is automatically included in <tt>ActionController::Base</tt>.
 module Turbo::Frames::FrameRequest
   extend ActiveSupport::Concern

diff --git a/test/frames/frame_request_controller_test.rb b/test/frames/frame_request_controller_test.rb
@@ -16,6 +16,15 @@ class Turbo::FrameRequestControllerTest < ActionDispatch::IntegrationTest
     assert_select "meta[name=test][content=present]"
   end
 
+  test "frame request layout can be overridden" do
+    with_prepended_view_path "test/frames/views" do
+      get tray_path(id: 1), headers: { "Turbo-Frame" => "true" }
+    end
+
+    assert_select "meta[name=test][content=present]"
+    assert_select "meta[name=alternative][content=present]"
+  end
+
   test "frame requests get a unique etag" do
     get tray_path(id: 1)
     etag_without_frame = @response.headers["ETag"]
@@ -35,4 +44,13 @@ class Turbo::FrameRequestControllerTest < ActionDispatch::IntegrationTest
     get tray_path(id: 1), headers: { "Turbo-Frame" => turbo_frame_request_id }
     assert_match /#{turbo_frame_request_id}/, @response.body
   end
+
+  private
+    def with_prepended_view_path(path, &block)
+      previous_view_paths = ApplicationController.view_paths
+      ApplicationController.prepend_view_path path
+      yield
+    ensure
+      ApplicationController.view_paths = previous_view_paths
+    end
 end
diff --git a/test/frames/views/layouts/turbo_rails/frame.html.erb b/test/frames/views/layouts/turbo_rails/frame.html.erb
@@ -0,0 +1,9 @@
+<html>
+  <head>
+    <meta name="alternative" content="present" />
+    <%= yield :head %>
+  </head>
+  <body>
+    <%= yield %>
+  </body>
+</html>