(Visual FoxPro) Async FTP Progress Info

Demonstrates checking for progress info updates when running a task asynchronously. This example demonstrates an FTP download.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loFtp
LOCAL lnSuccess
LOCAL lcLocalFilename
LOCAL lcRemoteFilename
LOCAL loTask
LOCAL lnCurPctDone
LOCAL lcName
LOCAL lcValue

* This example assumes the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Ftp2')
loFtp = CreateObject('Chilkat.Ftp2')

loFtp.Hostname = "ftp.someFtpServer.com"
lnSuccess = loFtp.ConnectOnly()
IF (lnSuccess <> 1) THEN
    ? loFtp.LastErrorText
    RELEASE loFtp
    CANCEL
ENDIF

loFtp.Username = "myLogin"
loFtp.Password = "myPassword"
lnSuccess = loFtp.LoginAfterConnectOnly()
IF (lnSuccess <> 1) THEN
    ? loFtp.LastErrorText
    RELEASE loFtp
    CANCEL
ENDIF

* Change to the remote directory where the file is located.
* This step is only necessary if the file is not in the root directory
* for the FTP account.
lnSuccess = loFtp.ChangeRemoteDir("someRemoteDirectory")
IF (lnSuccess <> 1) THEN
    ? loFtp.LastErrorText
    RELEASE loFtp
    CANCEL
ENDIF

lcLocalFilename = "/temp/romeo.xml"
lcRemoteFilename = "romeo.xml"

* --------------------
* Download a file
* --------------------

* Call the async version of the GetFile method to return a task object.
* The task object is loaded, but is in the Inert state -- meaning it is
* not yet scheduled to run on Chilkat's background thread pool.
loTask = loFtp.GetFileAsync(lcRemoteFilename,lcLocalFilename)
IF (loFtp.LastMethodSuccess = 0) THEN
    ? loFtp.LastErrorText
    RELEASE loFtp
    CANCEL
ENDIF

* Before starting the task, tell it to keep an in-memory log of what would've been
* ProgressInfo callbacks.
loTask.KeepProgressLog = 1

* Schedule the task for running on the thread pool.  This changes the task's state
* from Inert to Live.
lnSuccess = loTask.Run()
IF (lnSuccess <> 1) THEN
    ? loTask.LastErrorText
    RELEASE loTask
    RELEASE loFtp
    CANCEL
ENDIF

* The application is now free to do anything else
* while the file is being downloaded.

* For this example, we'll simply sleep and periodically
* check to see if the download is finished, and report the progress
* along the way.
lnCurPctDone = 0

DO WHILE loTask.Finished <> 1

    IF (loTask.PercentDone <> lnCurPctDone) THEN
        lnCurPctDone = loTask.PercentDone
        ? STR(lnCurPctDone) + " percent done"
    ENDIF

    * Check the progress info log.
    * Emit any log entries..
    DO WHILE (loTask.ProgressLogSize > 0)
        * Get the 1st entry, emit it, and then remove it..
        lcName = loTask.ProgressInfoName(0)
        lcValue = loTask.ProgressInfoValue(0)

        * Entries reporting the received byte count will have the name "RcvByteCount"
        * Entries reporting the current bytes-per-second will have the name "RcvBytesPerSec"

        ? lcName + ": " + lcValue
        loTask.RemoveProgressInfo(0)
    ENDDO

    * Sleep 100 ms.
    loTask.SleepMs(100)

ENDDO

* Just in case there are any remaining entries...
DO WHILE (loTask.ProgressLogSize > 0)
    * Get the 1st entry, emit it, and then remove it..
    lcName = loTask.ProgressInfoName(0)
    lcValue = loTask.ProgressInfoValue(0)
    ? lcName + ": " + lcValue
    loTask.RemoveProgressInfo(0)
ENDDO

* A finished task could be one that was canceled, aborted, or truly finished.  

* If the task was "canceled", it was canceled prior to actually starting.  This could
* happen if the task was canceled while waiting in a thread pool queue to be scheduled by Chilkat's
* background thread pool scheduler.  

* If the task was "aborted", it indicates that it was canceled while running in a background thread.  
* The ResultErrorText will likely indicate that the task was aborted.

* If the task "completed", then it ran to completion, but the actual success/failure of the method
* is determined by the result obtained via a GetResult* method.  (A "completed" task will
* have a StatusInt equal to 7.   If the task finished, but was not completed, then it must've
* been aborted or canceled:
IF (loTask.StatusInt <> 7) THEN
    ? "Task did not complete."
    ? "task status: " + loTask.Status
    RELEASE loTask
    RELEASE loFtp
    CANCEL
ENDIF

* The GetFile method returns a boolean.  Therefore, after the task is finished,
* we can get the boolean result by calling GetResultBool.  This is the return value had
* we called GetFile synchronously.
lnSuccess = loTask.GetResultBool()
IF (lnSuccess <> 1) THEN
    * The task's ResultErrorText contains what would have been in the LastErrorText property had
    * the GetFile method been called synchronously.
    ? loTask.ResultErrorText
ELSE
    ? "File downloaded asynchronously."
ENDIF

RELEASE loTask

lnSuccess = loFtp.Disconnect()

RELEASE loFtp