diff --git a/lib/install/tailwindcss.rb b/lib/install/tailwindcss.rb
index 413f86b8..40f18746 100644
--- a/lib/install/tailwindcss.rb
+++ b/lib/install/tailwindcss.rb
@@ -1,5 +1,6 @@
APPLICATION_LAYOUT_PATH = Rails.root.join("app/views/layouts/application.html.erb")
CENTERING_CONTAINER_INSERTION_POINT = /^\s*<%= yield %>/.freeze
+DEVELOPMENT_ENVIRONMENT_CONFIG_PATH = Rails.root.join("config/environments/development.rb")
if APPLICATION_LAYOUT_PATH.exist?
say "Add Tailwindcss include tags and container element in application layout"
@@ -16,6 +17,15 @@
say %( Add <%= stylesheet_link_tag "tailwind", "inter-font", "data-turbo-track": "reload" %> within the <head> tag in your custom layout.)
end
+if DEVELOPMENT_ENVIRONMENT_CONFIG_PATH.exist?
+ say "Enable Tailwindcss server process in development"
+ insert_into_file DEVELOPMENT_ENVIRONMENT_CONFIG_PATH.to_s, <<~ERB.indent(2), before: /^end$/
+
+ # Automatically watch and build Tailwindcss when 'rails server' is started.
+ config.tailwindcss.server_process = true
+ ERB
+end
+
say "Build into app/assets/builds"
empty_directory "app/assets/builds"
keep_file "app/assets/builds"
diff --git a/lib/tailwindcss-rails.rb b/lib/tailwindcss-rails.rb
index 112809c5..867663c6 100644
--- a/lib/tailwindcss-rails.rb
+++ b/lib/tailwindcss-rails.rb
@@ -5,3 +5,4 @@ module Tailwindcss
require_relative "tailwindcss/version"
require_relative "tailwindcss/engine"
require_relative "tailwindcss/commands"
+require_relative "tailwindcss/server_process"
diff --git a/lib/tailwindcss/engine.rb b/lib/tailwindcss/engine.rb
index 4b9b9fdc..fb60f1e3 100644
--- a/lib/tailwindcss/engine.rb
+++ b/lib/tailwindcss/engine.rb
@@ -2,6 +2,9 @@
module Tailwindcss
class Engine < ::Rails::Engine
+ config.tailwindcss = ActiveSupport::OrderedOptions.new
+ config.tailwindcss.server_process = false # Rails.env.development?
+
initializer "tailwindcss.assets" do
Rails.application.config.assets.precompile += %w( inter-font.css )
end
@@ -13,5 +16,9 @@ class Engine < ::Rails::Engine
config.app_generators do |g|
g.template_engine :tailwindcss
end
+
+ server do
+ ServerProcess.start if config.tailwindcss.server_process
+ end
end
end
diff --git a/lib/tailwindcss/server_process.rb b/lib/tailwindcss/server_process.rb
new file mode 100644
index 00000000..fbca382c
--- /dev/null
+++ b/lib/tailwindcss/server_process.rb
@@ -0,0 +1,149 @@
+module Tailwindcss
+ class ServerProcess
+ attr_reader :server, :pid
+
+ def self.start
+ new.start
+ end
+
+ def initialize
+ @server = Server.new(self)
+ end
+
+ def start
+ @pid = existing_process || start_process
+ server.monitor_process
+ server.exit_hook
+ end
+
+ def stop
+ return if dead?
+
+ Process.kill(:INT, pid)
+ Process.wait(pid)
+ rescue Errno::ECHILD, Errno::ESRCH
+ end
+
+ def dead?
+ Process.wait(pid, Process::WNOHANG)
+ false
+ rescue Errno::ECHILD, Errno::ESRCH
+ true
+ end
+
+ private
+
+ def existing_process
+ if (pid = Pidfile.pid)
+ begin
+ Process.kill 0, pid
+ pid
+ rescue Errno::ESRCH
+ # Process does not exist
+ rescue Errno::EPERM
+ # Ignore process owned by another user
+ end
+ end
+ end
+
+ def start_process
+ pid = fork do
+ Pidfile.write
+ monitor_server
+ exit_hook
+ # Using IO.popen(command, 'r+') will avoid watch_command read from $stdin.
+ # If we use system(*command) instead, IRB and Debug can't read from $stdin
+ # correctly bacause some keystrokes will be taken by watch_command.
+ IO.popen(Commands.watch_command, 'r+') do |io|
+ IO.copy_stream(io, $stdout)
+ end
+ ensure
+ Pidfile.delete
+ end
+ Process.detach pid
+ pid
+ end
+
+ def monitor_server
+ Thread.new do
+ loop do
+ if server.dead?
+ puts "Tailwind detected server has gone away"
+ exit
+ end
+ sleep 2
+ end
+ end
+ end
+
+ def exit_hook
+ at_exit do
+ puts "Stopping tailwind..."
+ server.stop
+ end
+ end
+
+ module Pidfile
+ def self.path
+ Rails.root.join("tmp", "pids", "tailwindcss.txt")
+ end
+
+ def self.read
+ File.read(path, mode: "rb:UTF-8")
+ rescue Errno::ENOENT
+ # File does not exist
+ end
+
+ def self.write
+ File.write(path, Process.pid, mode: "wb:UTF-8")
+ end
+
+ def self.delete
+ File.exist?(path) && File.delete(path)
+ end
+
+ def self.pid
+ Integer(read)
+ rescue ArgumentError, TypeError
+ # Invalid content
+ delete
+ end
+ end
+
+ class Server
+ attr_reader :process, :pid
+
+ def initialize(process)
+ @process = process
+ @pid = Process.pid
+ end
+
+ def monitor_process
+ Thread.new do
+ loop do
+ if process.dead?
+ puts "Detected tailwind has gone away, stopping server..."
+ exit
+ end
+ sleep 2
+ end
+ end
+ end
+
+ def exit_hook
+ at_exit do
+ process.stop
+ end
+ end
+
+ def dead?
+ Process.ppid != pid
+ end
+
+ def stop
+ Process.kill(:INT, pid)
+ rescue Errno::ECHILD, Errno::ESRCH
+ end
+ end
+ end
+end