poll.coffee

poll.coffee

# Periodically call the condition promise, resolves when the condition resolves
poll = (condition, interval=1000, timeout=60000)->
  promise = Q.promise (resolve, reject)->
    start = _.now()
    test = ->
      _duration = _.now() - start
      if _duration > timeout
        reject "Polling timeout of #{ timeout }ms exceeded."
      else
        Q.fcall(condition).then resolve
    test()
    _loop = setInterval test, interval

  promise.fin -> clearTimeout _loop
  promise