Polling Queue

polling_queue.js.coffee

class @PollingQueue
  constructor: (opts) ->
    opts || (opts = {})

    @queue     = {}
    @frequency = opts.frequency || 3000 # 3 seconds
    @interval  = undefined

  add: (url, options = {}) ->
    return unless url

    request = {
      url: url,
      params: {},
    }

    if options.params
      request.params = options.params

    if options.success
      request.success = options.success

    if options.stopPolling
      request.stopPolling = options.stopPolling

    # store by url to know to which one belongs the aja response
    @queue[url] ||= []
    @queue[url].push(request)

  processQueue: () ->
    for url, requests of @queue
      @process(url, requests)

  process: (url, requests) ->
    error = (xhr, status, error) =>
      for request in requests
        @queue[request.url].splice(@queue[request.url].indexOf(request), 1)
        return

    success = (response, status, xhr) =>
      for request in requests
        request.success?.call(this, response)

        if request.stopPolling && request.stopPolling(response)
          @queue[request.url].splice(@queue[request.url].indexOf(request), 1)

        return

    for request in requests
      $.ajax({
        url:     request.url,
        data:    request.params,
        error:   error,
        success: success,
      })

  polling: () ->
    @processQueue()

    unless @interval
      @interval = setInterval @polling.bind(@), @frequency

    if @queue.length == 0
      clearInterval @interval
      @interval = undefined