gistfile1.rb

class HammerCommand < Clamp::Command

  ALLOWED_CONTENT_TYPES = %w[ json yaml text ]

  option ["-d", "--debug"], :flag, "Output more information"
  option ["-u", "--user"], "USER", "Foreman user"
  option ["-p", "--pass"], "PASSWORD", "Foreman password"
  option ["-s", "--server"], "URL", "Foreman Server URL", :default => "http://localhost/"
  option "--format", "FORMAT", "Output format", :default => "json"
  option "--version", :flag, "show version" do
    puts "hammer-1.0.0"
    exit(0)
  end

  private

  def format= s
    raise ArgumentError, "must be one of: #{ALLOWED_CONTENT_TYPES.join(', ')}" unless ALLOWED_CONTENT_TYPES.include?(s)
    @format = s
  end

end

class HostListCommand < HammerCommand
  ALLOWED_CONTENT_TYPES = %w[ json yaml text something_else ]

  def execute
    ForemanResource::print_response(ForemanResource::get_collection('hosts', {:foreman_url => server, :foreman_user => user, :foreman_pass => pass, :debug => debug?}), format)
  end
end

def SomeOtherCommand < HammerCommand
  
  def format= s
    # do something really diffferent here
  end
end