1 files changed, 96 insertions, 0 deletions
diff --git a/actionview/lib/action_view/view_paths.rb b/actionview/lib/action_view/view_paths.rb
new file mode 100644
index 0000000000..6c349feb1d
--- /dev/null
+++ b/actionview/lib/action_view/view_paths.rb
@@ -0,0 +1,96 @@
+require 'action_view/base'
+
+module ActionView
+  module ViewPaths
+    extend ActiveSupport::Concern
+
+    included do
+      class_attribute :_view_paths
+      self._view_paths = ActionView::PathSet.new
+      self._view_paths.freeze
+    end
+
+    delegate :template_exists?, :view_paths, :formats, :formats=,
+             :locale, :locale=, :to => :lookup_context
+
+    module ClassMethods
+      def parent_prefixes
+        @parent_prefixes ||= begin
+          parent_controller = superclass
+          prefixes = []
+
+          until parent_controller.abstract?
+            prefixes << parent_controller.controller_path
+            parent_controller = parent_controller.superclass
+          end
+
+          prefixes
+        end
+      end
+    end
+
+    # The prefixes used in render "foo" shortcuts.
+    def _prefixes
+      @_prefixes ||= begin
+        parent_prefixes = self.class.parent_prefixes
+        parent_prefixes.dup.unshift(controller_path)
+      end
+    end
+
+    # LookupContext is the object responsible to hold all information required to lookup
+    # templates, i.e. view paths and details. Check ActionView::LookupContext for more
+    # information.
+    def lookup_context
+      @_lookup_context ||=
+        ActionView::LookupContext.new(self.class._view_paths, details_for_lookup, _prefixes)
+    end
+
+    def details_for_lookup
+      { }
+    end
+
+    def append_view_path(path)
+      lookup_context.view_paths.push(*path)
+    end
+
+    def prepend_view_path(path)
+      lookup_context.view_paths.unshift(*path)
+    end
+
+    module ClassMethods
+      # Append a path to the list of view paths for this controller.
+      #
+      # ==== Parameters
+      # * <tt>path</tt> - If a String is provided, it gets converted into
+      #   the default view path. You may also provide a custom view path
+      #   (see ActionView::PathSet for more information)
+      def append_view_path(path)
+        self._view_paths = view_paths + Array(path)
+      end
+
+      # Prepend a path to the list of view paths for this controller.
+      #
+      # ==== Parameters
+      # * <tt>path</tt> - If a String is provided, it gets converted into
+      #   the default view path. You may also provide a custom view path
+      #   (see ActionView::PathSet for more information)
+      def prepend_view_path(path)
+        self._view_paths = ActionView::PathSet.new(Array(path) + view_paths)
+      end
+
+      # A list of all of the default view paths for this controller.
+      def view_paths
+        _view_paths
+      end
+
+      # Set the view paths.
+      #
+      # ==== Parameters
+      # * <tt>paths</tt> - If a PathSet is provided, use that;
+      #   otherwise, process the parameter into a PathSet.
+      def view_paths=(paths)
+        self._view_paths = ActionView::PathSet.new(Array(paths))
+      end
+    end
+  end
+end