em-hiredis watch-multi-exec example

watch.rb

require 'em-hiredis'

EM.run {
  redis = EM::Hiredis.connect
  
  redis.set('foo', 'value')
  
  redis.watch('foo') {
    puts "Watching - try changing key foo within 1s"
    EM.add_timer(1) {
      redis.multi
      redis.get('foo')
      df = redis.exec
      df.callback { |get_result|
        if get_result
          p [:foo, get_result]
        else
          puts "Multi/exec failed"
        end
      }
    }
  } 
}