kugaevsky/guard-haml

# encoding: utf-8

require 'guard'
require 'guard/guard'
require 'guard/watcher'
require 'haml'

module Guard
  class Haml < Guard
    autoload :Notifier, 'guard/haml/notifier'

    def initialize(watchers = [], options = {})
      @options = {
        :notifications => true
      }.merge options
      super(watchers, @options)
    end

    def start
      run_all if @options[:run_at_start]
    end

    def stop
      true
    end

    def reload
      run_all
    end

    def run_all
      run_on_changes(Watcher.match_files(self, Dir.glob(File.join('**', '*.*'))))
    end

    def run_on_changes(paths)
      paths.each do |file|
        output_file = get_output(file)
        FileUtils.mkdir_p File.dirname(output_file)
        File.open(output_file, 'w') { |f| f.write(compile_haml(file)) }
        message = "Successfully compiled haml to html!\n"
        message += "# #{file} → #{output_file}".gsub("#{Bundler.root.to_s}/", '')
        ::Guard::UI.info message
        Notifier.notify( true, message ) if @options[:notifications]
      end
      notify paths
    end

    private

    def compile_haml file
      begin
        content = File.new(file).read
        engine  = ::Haml::Engine.new(content, (@options[:haml_options] || {}))
        engine.render
      rescue StandardError => error
        message = "HAML compilation failed!\nError: #{error.message}"
        ::Guard::UI.error message
        Notifier.notify( false, message ) if @options[:notifications]
        throw :task_has_failed
      end
    end

    # Get the file path to output the html based on the file being
    # built. The output path is relative to where guard is being run.
    #
    # @param file [String] path to file being built
    # @return [String] path to file where output should be written
    #
    def get_output(file)
      file_dir = File.dirname(file)
      file_name = File.basename(file).split('.')[0..-2].join('.')

      file_name = "#{file_name}.html" if file_name.match("\.html?").nil?

      file_dir = file_dir.gsub(Regexp.new("#{@options[:input]}(\/){0,1}"), '') if @options[:input]
      file_dir = File.join(@options[:output], file_dir) if @options[:output]

      if file_dir == ''
        file_name
      else
        File.join(file_dir, file_name)
      end
    end

    def notify(changed_files)
      ::Guard.guards.reject{ |guard| guard == self }.each do |guard|
        paths = Watcher.match_files(guard, changed_files)
        guard.run_on_changes paths unless paths.empty?
      end
    end
  end
end