Allow template handlers to store temp data.

actionpack/lib/action_view/template.rb

@@ -184,6 +184,11 @@ def rerender(view)
       end
     end
 
+    # Used to store template data by template handlers.
+    def data
+      @data ||= {}
+    end
+
     def inspect
       @inspect ||=
         if defined?(Rails.root)

actionpack/test/template/lookup_context_test.rb

@@ -180,6 +180,16 @@ def teardown
 
     assert_not_equal template, old_template
   end
+
+  test "data can be stored in cached templates" do
+    template = @lookup_context.find("hello_world", "test")
+    template.data["cached"] = "data"
+    assert_equal "Hello world!", template.source
+
+    template = @lookup_context.find("hello_world", "test")
+    assert_equal "data", template.data["cached"]
+    assert_equal "Hello world!", template.source
+  end
 end
 
 class LookupContextWithFalseCaching < ActiveSupport::TestCase
@@ -205,7 +215,7 @@ def setup
     assert_equal "Bar", template.source
   end
 
-  test "if no template was found in the second lookup, give it higher preference" do
+  test "if no template was found in the second lookup, with no cache, raise error" do
     template = @lookup_context.find("foo", "test", true)
     assert_equal "Foo", template.source
 
@@ -215,7 +225,7 @@ def setup
     end
   end
 
-  test "if no template was cached in the first lookup, do not use the cache in the second" do
+  test "if no template was cached in the first lookup, retrieval should work in the second call" do
     @resolver.hash.clear
     assert_raise ActionView::MissingTemplate do
       @lookup_context.find("foo", "test", true)
@@ -225,4 +235,19 @@ def setup
     template = @lookup_context.find("foo", "test", true)
     assert_equal "Foo", template.source
   end
+
+  test "data can be stored as long as template was not updated" do
+    template = @lookup_context.find("foo", "test", true)
+    template.data["cached"] = "data"
+    assert_equal "Foo", template.source
+
+    template = @lookup_context.find("foo", "test", true)
+    assert_equal "data", template.data["cached"]
+    assert_equal "Foo", template.source
+
+    @resolver.hash["test/_foo.erb"][1] = Time.now.utc
+    template = @lookup_context.find("foo", "test", true)
+    assert_nil template.data["cached"]
+    assert_equal "Foo", template.source
+  end
 end