(Lianja) Async FTP Progress Info

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

Chilkat Lianja Extension Download Chilkat Lianja Extension

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

loFtp = createobject("CkFtp2")

loFtp.Hostname = "ftp.someFtpServer.com"
llSuccess = loFtp.ConnectOnly()
if (llSuccess <> .T.) then
    ? loFtp.LastErrorText
    release loFtp
    return
endif

loFtp.Username = "myLogin"
loFtp.Password = "myPassword"
llSuccess = loFtp.LoginAfterConnectOnly()
if (llSuccess <> .T.) then
    ? loFtp.LastErrorText
    release loFtp
    return
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.
llSuccess = loFtp.ChangeRemoteDir("someRemoteDirectory")
if (llSuccess <> .T.) then
    ? loFtp.LastErrorText
    release loFtp
    return
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 = .F.) then
    ? loFtp.LastErrorText
    release loFtp
    return
endif

// Before starting the task, tell it to keep an in-memory log of what would've been
// ProgressInfo callbacks.
loTask.KeepProgressLog = .T.

// Schedule the task for running on the thread pool.  This changes the task's state
// from Inert to Live.
llSuccess = loTask.Run()
if (llSuccess <> .T.) then
    ? loTask.LastErrorText
    release loTask
    release loFtp
    return
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 <> .T.

    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
    return
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.
llSuccess = loTask.GetResultBool()
if (llSuccess <> .T.) 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

llSuccess = loFtp.Disconnect()


release loFtp