Return rendered template information instead of just strings

This commit introduces "rendered template" and "rendered collection"
objects.  The template renderers can now return a more complex object
than just strings.  This allows the framework to get more information
about the templates that were rendered.  In this commit we use the
rendered template object to set the "rendered_format" on the lookup
context in the controller rather than all the way in the template renderer.
That means we don't need to check the "rendered_format" every time we
render a template, we just do it once after all templates have been
rendered.

1 files changed, 10 insertions, 15 deletions

diff --git a/actionview/lib/action_view/renderer/partial_renderer.rb b/actionview/lib/action_view/renderer/partial_renderer.rb
index f8a6f13ae9..f4319b8528 100644
--- a/actionview/lib/action_view/renderer/partial_renderer.rb
+++ b/actionview/lib/action_view/renderer/partial_renderer.rb
@@ -314,14 +314,6 @@ module ActionView
         template = nil
       end
 
-      @lookup_context.rendered_format ||= begin
-        if template && template.formats.first
-          template.formats.first
-        else
-          formats.first
-        end
-      end
-
       if @collection
         render_collection(context, template)
       else
@@ -334,10 +326,13 @@ module ActionView
       def render_collection(view, template)
         identifier = (template && template.identifier) || @path
         instrument(:collection, identifier: identifier, count: @collection.size) do |payload|
-          return nil if @collection.blank?
+          return RenderedCollection::EMPTY if @collection.blank?
 
-          if @options.key?(:spacer_template)
-            spacer = find_template(@options[:spacer_template], @locals.keys).render(view, @locals)
+          spacer = if @options.key?(:spacer_template)
+            spacer_template = find_template(@options[:spacer_template], @locals.keys)
+            build_rendered_template(spacer_template.render(view, @locals), nil, spacer_template)
+          else
+            RenderedTemplate::EMPTY_SPACER
           end
 
           collection_body = if template
@@ -347,7 +342,7 @@ module ActionView
           else
             collection_without_template(view)
           end
-          collection_body.join(spacer).html_safe
+          build_rendered_collection(collection_body, spacer)
         end
       end
 
@@ -369,7 +364,7 @@ module ActionView
 
           content = layout.render(view, locals) { content } if layout
           payload[:cache_hit] = view.view_renderer.cache_hits[template.virtual_path]
-          content
+          build_rendered_template(content, layout, template)
         end
       end
 
@@ -460,7 +455,7 @@ module ActionView
           content = template.render(view, locals)
           content = layout.render(view, locals) { content } if layout
           partial_iteration.iterate!
-          content
+          build_rendered_template(content, layout, template)
         end
       end
 
@@ -482,7 +477,7 @@ module ActionView
           template = (cache[path] ||= find_template(path, keys + [as, counter, iteration]))
           content = template.render(view, locals)
           partial_iteration.iterate!
-          content
+          build_rendered_template(content, nil, template)
         end
       end