1 files changed, 93 insertions, 0 deletions
diff --git a/actionpack/lib/action_view/template/renderable.rb b/actionpack/lib/action_view/template/renderable.rb
new file mode 100644
index 0000000000..54857516ab
--- /dev/null
+++ b/actionpack/lib/action_view/template/renderable.rb
@@ -0,0 +1,93 @@
+# encoding: utf-8
+
+module ActionView
+  # NOTE: The template that this mixin is being included into is frozen
+  # so you cannot set or modify any instance variables
+  module Renderable #:nodoc:
+    extend ActiveSupport::Memoizable
+
+    def render(view, locals)
+      compile(locals)
+      view.send(method_name(locals), locals) {|*args| yield(*args) }
+    end
+    
+    def load!
+      names = Base::CompiledTemplates.instance_methods.grep(/#{method_name_without_locals}/)
+      names.each do |name|
+        Base::CompiledTemplates.class_eval do
+          remove_method(name)
+        end
+      end
+      super
+    end
+    
+  private
+  
+    def filename
+      'compiled-template'
+    end
+
+    def handler
+      Template.handler_class_for_extension(extension)
+    end
+    memoize :handler
+
+    def compiled_source
+      handler.call(self)
+    end
+    memoize :compiled_source
+
+    def method_name_without_locals
+      ['_run', extension, method_segment].compact.join('_')
+    end
+    memoize :method_name_without_locals
+
+    def method_name(local_assigns)
+      if local_assigns && local_assigns.any?
+        method_name = method_name_without_locals.dup
+        method_name << "_locals_#{local_assigns.keys.map { |k| k.to_s }.sort.join('_')}"
+      else
+        method_name = method_name_without_locals
+      end
+      method_name.to_sym
+    end
+
+    # Compile and evaluate the template's code (if necessary)
+    def compile(local_assigns)
+      render_symbol = method_name(local_assigns)
+
+      if !Base::CompiledTemplates.method_defined?(render_symbol) || recompile?
+        compile!(render_symbol, local_assigns)
+      end
+    end
+
+    private
+      def compile!(render_symbol, local_assigns)
+        locals_code = local_assigns.keys.map { |key| "#{key} = local_assigns[:#{key}];" }.join
+
+        source = <<-end_src
+          def #{render_symbol}(local_assigns)
+            old_output_buffer = output_buffer;#{locals_code};#{compiled_source}
+          ensure
+            self.output_buffer = old_output_buffer
+          end
+        end_src
+
+        begin
+          ActionView::Base::CompiledTemplates.module_eval(source, filename.to_s, 0)
+        rescue Exception => e # errors from template code
+          if logger = defined?(ActionController) && Base.logger
+            logger.debug "ERROR: compiling #{render_symbol} RAISED #{e}"
+            logger.debug "Function body: #{source}"
+            logger.debug "Backtrace: #{e.backtrace.join("\n")}"
+          end
+
+          raise ActionView::TemplateError.new(self, {}, e)
+        end
+      end
+
+      def recompile?
+        false
+      end
+  end
+end