From 6a622efb67cae0cfbd1039db7b163f47424dc9be Mon Sep 17 00:00:00 2001
From: Jan Nash <jnash@jnash.de>
Date: Sun, 4 May 2025 09:53:43 +0200
Subject: [PATCH] feat: make input and output filenames for build and watch
 configurable

---
 lib/tailwindcss/commands.rb | 26 +++++++++++++++++++++++---
 lib/tasks/build.rake        | 17 +++++++++++++++--
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/lib/tailwindcss/commands.rb b/lib/tailwindcss/commands.rb
index 99ad30e..4c255cb 100644
--- a/lib/tailwindcss/commands.rb
+++ b/lib/tailwindcss/commands.rb
@@ -3,14 +3,16 @@
 module Tailwindcss
   module Commands
     class << self
-      def compile_command(debug: false, **kwargs)
+      def compile_command(debug: false, namespace: nil, **kwargs)
         debug = ENV["TAILWINDCSS_DEBUG"].present? if ENV.key?("TAILWINDCSS_DEBUG")
         rails_root = defined?(Rails) ? Rails.root : Pathname.new(Dir.pwd)
 
+        input_filename, output_filename = get_input_and_output_filename(namespace)
+
         command = [
           Tailwindcss::Ruby.executable(**kwargs),
-          "-i", rails_root.join("app/assets/tailwind/application.css").to_s,
-          "-o", rails_root.join("app/assets/builds/tailwind.css").to_s,
+          "-i", rails_root.join("app/assets/tailwind/#{input_filename}.css").to_s,
+          "-o", rails_root.join("app/assets/builds/#{output_filename}.css").to_s,
         ]
 
         command << "--minify" unless (debug || rails_css_compressor?)
@@ -35,9 +37,27 @@ def command_env(verbose:)
         end
       end
 
+      private
+
       def rails_css_compressor?
         defined?(Rails) && Rails&.application&.config&.assets&.css_compressor.present?
       end
+
+      def get_input_and_output_filename(namespace)
+        if namespace != nil
+          unless File.exist?("app/assets/tailwind/#{namespace}.css")
+            raise "No file named #{namespace}.css exists in app/assets/tailwind"
+          end
+
+          if namespace == "application"
+            raise "application.css is the default input file for tailwind and cannot be used as namespace. If you want the normal behaviour of tailwindcss (to compile application.css into tailwind.css), just omit the namespace parameter."
+          end
+        end
+
+        input_filename = namespace || "application"
+        output_filename = namespace || "tailwind"
+        return input_filename, output_filename
+      end
     end
   end
 end
diff --git a/lib/tasks/build.rake b/lib/tasks/build.rake
index 603c805..541c0d0 100644
--- a/lib/tasks/build.rake
+++ b/lib/tasks/build.rake
@@ -4,7 +4,9 @@ namespace :tailwindcss do
     debug = args.extras.include?("debug")
     verbose = args.extras.include?("verbose")
 
-    command = Tailwindcss::Commands.compile_command(debug: debug)
+    namespace = get_namespace_from_extras(args.extras)
+
+    command = Tailwindcss::Commands.compile_command(debug: debug, namespace: namespace)
     env = Tailwindcss::Commands.command_env(verbose: verbose)
     puts "Running: #{Shellwords.join(command)}" if verbose
 
@@ -18,7 +20,9 @@ namespace :tailwindcss do
     always = args.extras.include?("always")
     verbose = args.extras.include?("verbose")
 
-    command = Tailwindcss::Commands.watch_command(always: always, debug: debug, poll: poll)
+    namespace = get_namespace_from_extras(args.extras)
+
+    command = Tailwindcss::Commands.watch_command(always: always, debug: debug, namespace: namespace, poll: poll)
     env = Tailwindcss::Commands.command_env(verbose: verbose)
     puts "Running: #{Shellwords.join(command)}" if verbose
 
@@ -26,6 +30,15 @@ namespace :tailwindcss do
   rescue Interrupt
     puts "Received interrupt, exiting tailwindcss:watch" if args.extras.include?("verbose")
   end
+
+  private
+
+  def get_namespace_from_extras(extras)
+    namespace_key_and_value = extras.detect{ |a| a.start_with?('namespace=') }
+    if namespace_key_and_value != nil
+      namespace_key_and_value.split('=')[1]
+    end
+  end
 end
 
 Rake::Task["assets:precompile"].enhance(["tailwindcss:build"])