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Copyright 2012 The Apache Software Foundation

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.


define ["./events", "./dom", "./console"],
  (events, dom, console) ->

Initialize a timer for the zone at the specified period (in seconds). The zone will be refreshed with the provided URL.

    initialize = (zoneId, period, url) ->
      zone = dom zoneId

      unless zone
        console.err "Zone #{zoneId} not found for periodic refresh."

Only one periodic refresh per zone.

      return if zone.meta "periodic-refresh"

      zone.meta "periodic-refresh", true

      executing = false

Whenever the zone updates, we can clear the executing flag.

      zone.on events.zone.didUpdate, -> executing = false

      cleanUp = ->
        window.clearInterval intervalId
        zone = null

      handler = ->

Don't clog things up if the response rate is too slow

        return if executing

If the zone element is no longer part of the DOM, stop the timer

        unless (zone.closest 'body')

Set the flag now, it will clear when the zone updates.

        executing = true

        zone.trigger events.zone.refresh, { url }

      intervalId = window.setInterval handler, period * 1000

Not sure if this is needed except for IE:

      (dom window).on "beforeunload", cleanUp

export the single function:

    return initialize