From 72bc1611f7df76397b58bad8ed0898ec449ec5fe Mon Sep 17 00:00:00 2001
From: Takashi Kokubun <takashikkbn@gmail.com>
Date: Tue, 23 Mar 2021 21:13:18 -0700
Subject: [PATCH] Support annotate_rendered_view_with_filenames

Fix #180
---
 lib/hamlit/ambles.rb         | 20 ++++++++++++++++++++
 lib/hamlit/engine.rb         |  2 ++
 lib/hamlit/rails_template.rb |  5 +++++
 3 files changed, 27 insertions(+)
 create mode 100644 lib/hamlit/ambles.rb

diff --git a/lib/hamlit/ambles.rb b/lib/hamlit/ambles.rb
new file mode 100644
index 00000000..3036a822
--- /dev/null
+++ b/lib/hamlit/ambles.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+module Hamlit
+  class Ambles < Temple::Filter
+    define_options :preamble, :postamble
+
+    def initialize(*)
+      super
+      @preamble = options[:preamble]
+      @postamble = options[:postamble]
+    end
+
+    def call(ast)
+      ret = [:multi]
+      ret << [:static, @preamble] if @preamble
+      ret << ast
+      ret << [:static, @postamble] if @postamble
+      ret
+    end
+  end
+end
diff --git a/lib/hamlit/engine.rb b/lib/hamlit/engine.rb
index 069f96b5..e901c9f8 100644
--- a/lib/hamlit/engine.rb
+++ b/lib/hamlit/engine.rb
@@ -6,6 +6,7 @@
 require 'hamlit/escapable'
 require 'hamlit/force_escapable'
 require 'hamlit/dynamic_merger'
+require 'hamlit/ambles'
 
 module Hamlit
   class Engine < Temple::Engine
@@ -33,6 +34,7 @@ class Engine < Temple::Engine
     filter :MultiFlattener
     filter :StaticMerger
     use DynamicMerger
+    use Ambles
     use :Generator, -> { options[:generator] }
   end
 end
diff --git a/lib/hamlit/rails_template.rb b/lib/hamlit/rails_template.rb
index e1723c44..2d1a3843 100644
--- a/lib/hamlit/rails_template.rb
+++ b/lib/hamlit/rails_template.rb
@@ -33,6 +33,11 @@ def call(template, source = nil)
         options = options.merge(format: :xhtml)
       end
 
+      if ActionView::Base.try(:annotate_rendered_view_with_filenames) && template.format == :html
+        options[:preamble] = "<!-- BEGIN #{template.short_identifier} -->\n"
+        options[:postamble] = "<!-- END #{template.short_identifier} -->\n"
+      end
+
       Engine.new(options).call(source)
     end