-- "NetOp.transaction" Parent Script (v.1)
-- @version 1.1

-- @Example Usage
--
--  on mouseUp me
--    urlStr = "http://www.lingoworkshop.com/"
--    netOp = script("NetOp.transaction").new(urlStr)
--    netOp.AddListener(me)
--    netOp.Start() 
--  end
--
--  on NetTransactionComplete (me, sender, args)
--    put "Net Transaction Complete: " & args 
--  end
--
--  on NetTransactionStatusUpdate(me, sender, args)
--    put "Net Transaction Status: " & args 
--  end

-- @Notes

-- Works as a self-contained 'daemon' (the timer instances create
-- keep the object alive. When the transaction is complete, the
-- timer is forgotten. If you have not kept another reference to the
-- instance, it will be destroyed automatically)

-- @Dependencies
-- script("NetOp")


property ancestor 
property NetID
property URL, FORMDATA

on new (me, netAddress, data)
  URL = netAddress
  FORMDATA = data
  ancestor = script("NetOp").rawNew()
  callAncestor(#new, me)
  return me
end

on Start (me)
  if voidP(FORMDATA) then NetID = getNetText(URL )
  else  NetID = postNetText(URL , FORMDATA)
  aTimerObj = timeout().new(me.string, 100, #Timer_CheckProgress, me)
  return NetID
end

on Destroy (me)
  netAbort(NetID)
  NetID = VOID
  callAncestor(#Destroy, me)
end

on Timer_CheckProgress (me, aTimer)
  if voidP(NetID) then
    -- we have aborted the operation
    atimer.forget()
    return 0
  end if
  
  finished = netDone(NetID)
  if finished then
    errorNum = netError(NetID)
    theText = netTextResult(NetID)
    if stringP(errorNum) then errorNum =0
    aTimer.forget()
    me.GenerateEventMessage(#NetTransactionComplete, [#Text: theText, #Error: errorNum])
  else
    -- check the current status 
    status = getStreamStatus(NetID)
    currentState = status.state
    -- before sending the status, work out the portion downloaded
    case (currentState) of 
      "InProgress":
        if status.bytesSoFar > 0 then 
          if status.bytesTotal > 0 then 
            f = MIN(1.0, float(status.bytesSoFar)/status.bytesTotal )
          else f = 0.50
        else
          f = 0
        end if
      "Complete":
        f = 1.00
      otherwise
        f = 0
    end case
    -- add the fractionDone as a property to the statusList
    status.addProp( #fractiondone, f )
    -- inform the callback object of the current state and the % transferred
    me.GenerateEventMessage(#NetTransactionStatusUpdate, status)
  end if
end