From d6b11c4405c03c237f96c80f5bd5aa0bf13f0c9d Mon Sep 17 00:00:00 2001
From: Jonathan Chan <jonathan@rentwayhome.com>
Date: Sat, 13 Jul 2024 00:24:12 -0500
Subject: [PATCH] utilizing bootstrap gem pick your own sass library code

---
 Gemfile                     |  3 +++
 README.md                   |  6 ++++++
 lib/rails_email_preview.rb  | 20 +++++++++++++++++++-
 rails_email_preview.gemspec |  1 -
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/Gemfile b/Gemfile
index 2fe87ba..b5d9c88 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,4 +5,7 @@ gemspec
 gem 'rails'
 gem 'i18n-tasks'
 
+# For development; when running as a library, you can pick your own sass compiler
+gem 'dartsass-sprockets'
+
 eval_gemfile './shared.gemfile'
diff --git a/README.md b/README.md
index a525880..531336b 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,12 @@ Add [![Gem Version][gem-badge]][gem] to Gemfile:
 gem 'rails_email_preview', '~> 2.2.3'
 ```
 
+This gem requires a Sass engine, please ensure you have **one** of these gems in your Gemfile:
+- [`dartsass-sprockets`](https://github.com/tablecheck/dartsass-sprockets): Dart Sass engine, recommended but only works for Ruby 2.6+ and Rails 5+
+- [`dartsass-rails`](https://github.com/rails/dartsass-rails): Dart Sass engine, recommended for Rails projects that use Propshaft
+- [`cssbundling-rails`](https://github.com/rails/cssbundling-rails): External Sass engine
+- [`sassc-rails`](https://github.com/sass/sassc-rails): SassC engine, deprecated but compatible with Ruby 2.3+ and Rails 4
+
 Add an initializer and the routes:
 
 ```console
diff --git a/lib/rails_email_preview.rb b/lib/rails_email_preview.rb
index 37c27de..6598d56 100644
--- a/lib/rails_email_preview.rb
+++ b/lib/rails_email_preview.rb
@@ -5,7 +5,25 @@
 require 'rails_email_preview/delivery_handler'
 require 'rails_email_preview/view_hooks'
 
-require 'dartsass-sprockets'
+# sass engine loader
+begin
+  require 'dartsass-sprockets'
+rescue LoadError
+  begin
+    require 'sassc-rails'
+  rescue LoadError
+    begin
+      require 'dartsass-rails'
+    rescue LoadError
+      begin
+        require 'cssbundling-rails'
+      rescue LoadError
+        raise LoadError.new("bootstrap-rubygem requires a Sass engine. Please add dartsass-sprockets, sassc-rails, dartsass-rails or cssbundling-rails to your dependencies.")
+      end
+    end
+  end
+end
+
 require 'request_store'
 require 'turbolinks'
 require 'pathname'
diff --git a/rails_email_preview.gemspec b/rails_email_preview.gemspec
index c5047d7..572f9c2 100644
--- a/rails_email_preview.gemspec
+++ b/rails_email_preview.gemspec
@@ -18,7 +18,6 @@ Gem::Specification.new do |s|
   end
 
   s.add_dependency 'rails', '>= 4.2'
-  s.add_dependency 'dartsass-sprockets'
   s.add_dependency 'turbolinks'
   s.add_dependency 'request_store'