Speed up performance in resolvers by adding fallbacks just when required.

1 files changed, 16 insertions, 0 deletions

diff --git a/actionpack/lib/action_view/lookup_context.rb b/actionpack/lib/action_view/lookup_context.rb
index 82aebe1678..e259a78c5c 100644
--- a/actionpack/lib/action_view/lookup_context.rb
+++ b/actionpack/lib/action_view/lookup_context.rb
@@ -6,6 +6,9 @@ module ActionView
   class LookupContext #:nodoc:
     attr_reader :details, :view_paths
 
+    mattr_accessor :fallbacks
+    @@fallbacks = [FileSystemResolver.new(""), FileSystemResolver.new("/")]
+
     class DetailsKey #:nodoc:
       attr_reader :details
       alias :eql? :equal?
@@ -69,6 +72,19 @@ module ActionView
       end
     end
 
+    # Added fallbacks to the view paths. Useful in cases you are rendering a file.
+    def with_fallbacks
+      added_resolvers = 0
+      self.class.fallbacks.each do |resolver|
+        next if view_paths.include?(resolver)
+        view_paths.push(resolver)
+        added_resolvers += 1
+      end
+      yield
+    ensure
+      added_resolvers.times { view_paths.pop }
+    end
+
     def find_template(name, prefix = nil, partial = false)
       @view_paths.find(name, details, prefix, partial || false, details_key)
     end