Merge pull request #35036 from rails/av-base-subclass

Move compiled ERB to an AV::Base subclass

6 files changed, 67 insertions, 40 deletions

diff --git a/actionview/lib/action_view.rb b/actionview/lib/action_view.rb
index 6ff2d70e35..8cb4648a67 100644
--- a/actionview/lib/action_view.rb
+++ b/actionview/lib/action_view.rb
@@ -35,7 +35,6 @@ module ActionView
   eager_autoload do
     autoload :Base
     autoload :Context
-    autoload :CompiledTemplates, "action_view/context"
     autoload :Digestor
     autoload :Helpers
     autoload :LookupContext
diff --git a/actionview/lib/action_view/base.rb b/actionview/lib/action_view/base.rb
index b143e13c96..420136d6de 100644
--- a/actionview/lib/action_view/base.rb
+++ b/actionview/lib/action_view/base.rb
@@ -11,10 +11,6 @@ require "action_view/template"
 require "action_view/lookup_context"
 
 module ActionView #:nodoc:
-  module CompiledTemplates #:nodoc:
-    # holds compiled template code
-  end
-
   # = Action View Base
   #
   # Action View templates can be written in several ways.
@@ -146,8 +142,6 @@ module ActionView #:nodoc:
   class Base
     include Helpers, ::ERB::Util, Context
 
-    include CompiledTemplates
-
     # Specify the proc used to decorate input tags that refer to attributes with errors.
     cattr_accessor :field_error_proc, default: Proc.new { |html_tag, instance| "<div class=\"field_with_errors\">#{html_tag}</div>".html_safe }
 
@@ -186,6 +180,20 @@ module ActionView #:nodoc:
       def xss_safe? #:nodoc:
         true
       end
+
+      def with_empty_template_cache # :nodoc:
+        subclass = Class.new(self) {
+          # We can't implement these as self.class because subclasses will
+          # share the same template cache as superclasses, so "changed?" won't work
+          # correctly.
+          define_method(:compiled_method_container)           { subclass }
+          define_singleton_method(:compiled_method_container) { subclass }
+        }
+      end
+
+      def changed?(other) # :nodoc:
+        compiled_method_container != other.compiled_method_container
+      end
     end
 
     attr_reader :view_renderer
@@ -260,7 +268,11 @@ module ActionView #:nodoc:
     end
 
     def compiled_method_container
-      CompiledTemplates
+      raise NotImplementedError, <<~msg
+        Subclasses of ActionView::Base must implement `compiled_method_container`
+        or use the class method `with_empty_template_cache` for constructing
+        an ActionView::Base subclass that has an empty cache.
+      msg
     end
 
     ActiveSupport.run_load_hooks(:action_view, self)
diff --git a/actionview/lib/action_view/lookup_context.rb b/actionview/lib/action_view/lookup_context.rb
index c2f6439e26..c3bb0a49fc 100644
--- a/actionview/lib/action_view/lookup_context.rb
+++ b/actionview/lib/action_view/lookup_context.rb
@@ -68,12 +68,17 @@ module ActionView
       end
 
       def self.clear
+        @view_context_class = nil
         @details_keys.clear
       end
 
       def self.digest_caches
         @details_keys.values
       end
+
+      def self.view_context_class(klass)
+        @view_context_class ||= klass.with_empty_template_cache
+      end
     end
 
     # Add caching behavior on top of Details.
diff --git a/actionview/lib/action_view/railtie.rb b/actionview/lib/action_view/railtie.rb
index 12d06bf376..a25e1d3d02 100644
--- a/actionview/lib/action_view/railtie.rb
+++ b/actionview/lib/action_view/railtie.rb
@@ -6,11 +6,13 @@ require "rails"
 module ActionView
   # = Action View Railtie
   class Railtie < Rails::Engine # :nodoc:
+    NULL_OPTION = Object.new
+
     config.action_view = ActiveSupport::OrderedOptions.new
     config.action_view.embed_authenticity_token_in_remote_forms = nil
     config.action_view.debug_missing_translation = true
     config.action_view.default_enforce_utf8 = nil
-    config.action_view.finalize_compiled_template_methods = true
+    config.action_view.finalize_compiled_template_methods = NULL_OPTION
 
     config.eager_load_namespaces << ActionView
 
@@ -48,8 +50,11 @@ module ActionView
 
     initializer "action_view.finalize_compiled_template_methods" do |app|
       ActiveSupport.on_load(:action_view) do
-        ActionView::Template.finalize_compiled_template_methods =
-          app.config.action_view.delete(:finalize_compiled_template_methods)
+        option = app.config.action_view.delete(:finalize_compiled_template_methods)
+
+        if option != NULL_OPTION
+          ActiveSupport::Deprecation.warn "action_view.finalize_compiled_template_methods is deprecated and has no effect"
+        end
       end
     end
 
diff --git a/actionview/lib/action_view/rendering.rb b/actionview/lib/action_view/rendering.rb
index 205665a8c6..cf7d1105e0 100644
--- a/actionview/lib/action_view/rendering.rb
+++ b/actionview/lib/action_view/rendering.rb
@@ -35,24 +35,36 @@ module ActionView
     end
 
     module ClassMethods
-      def view_context_class
-        @view_context_class ||= begin
-          supports_path = supports_path?
-          routes  = respond_to?(:_routes)  && _routes
-          helpers = respond_to?(:_helpers) && _helpers
-
-          Class.new(ActionView::Base) do
-            if routes
-              include routes.url_helpers(supports_path)
-              include routes.mounted_helpers
-            end
-
-            if helpers
-              include helpers
-            end
+      def _routes
+      end
+
+      def _helpers
+      end
+
+      def build_view_context_class(klass, supports_path, routes, helpers)
+        Class.new(klass) do
+          if routes
+            include routes.url_helpers(supports_path)
+            include routes.mounted_helpers
+          end
+
+          if helpers
+            include helpers
           end
         end
       end
+
+      def view_context_class
+        klass = ActionView::LookupContext::DetailsKey.view_context_class(ActionView::Base)
+
+        @view_context_class ||= build_view_context_class(klass, supports_path?, _routes, _helpers)
+
+        if klass.changed?(@view_context_class)
+          @view_context_class = build_view_context_class(klass, supports_path?, _routes, _helpers)
+        end
+
+        @view_context_class
+      end
     end
 
     def view_context_class
diff --git a/actionview/lib/action_view/template.rb b/actionview/lib/action_view/template.rb
index 8a5407c622..37f476e554 100644
--- a/actionview/lib/action_view/template.rb
+++ b/actionview/lib/action_view/template.rb
@@ -2,6 +2,7 @@
 
 require "active_support/core_ext/object/try"
 require "active_support/core_ext/kernel/singleton_class"
+require "active_support/deprecation"
 require "thread"
 require "delegate"
 
@@ -10,7 +11,13 @@ module ActionView
   class Template
     extend ActiveSupport::Autoload
 
-    mattr_accessor :finalize_compiled_template_methods, default: true
+    def self.finalize_compiled_template_methods
+      ActiveSupport::Deprecation.warn "ActionView::Template.finalize_compiled_template_methods is deprecated and has no effect"
+    end
+
+    def self.finalize_compiled_template_methods=(_)
+      ActiveSupport::Deprecation.warn "ActionView::Template.finalize_compiled_template_methods= is deprecated and has no effect"
+    end
 
     # === Encodings in ActionView::Template
     #
@@ -118,16 +125,6 @@ module ActionView
 
     attr_reader :source, :identifier, :handler, :original_encoding, :updated_at
 
-    # This finalizer is needed (and exactly with a proc inside another proc)
-    # otherwise templates leak in development.
-    Finalizer = proc do |method_name, mod| # :nodoc:
-      proc do
-        mod.module_eval do
-          remove_possible_method method_name
-        end
-      end
-    end
-
     attr_reader :variable
 
     def initialize(source, identifier, handler, details)
@@ -337,9 +334,6 @@ module ActionView
         end
 
         mod.module_eval(source, identifier, 0)
-        if finalize_compiled_template_methods
-          ObjectSpace.define_finalizer(self, Finalizer[method_name, mod])
-        end
       end
 
       def handle_render_error(view, e)