(PureBasic) Async FTP Progress Info

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

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkFtp2.pb"
IncludeFile "CkTask.pb"

Procedure ChilkatExample()

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

    ftp.i = CkFtp2::ckCreate()
    If ftp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkFtp2::setCkHostname(ftp, "ftp.someFtpServer.com")
    success.i = CkFtp2::ckConnectOnly(ftp)
    If success <> 1
        Debug CkFtp2::ckLastErrorText(ftp)
        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    EndIf

    CkFtp2::setCkUsername(ftp, "myLogin")
    CkFtp2::setCkPassword(ftp, "myPassword")
    success = CkFtp2::ckLoginAfterConnectOnly(ftp)
    If success <> 1
        Debug CkFtp2::ckLastErrorText(ftp)
        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    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.
    success = CkFtp2::ckChangeRemoteDir(ftp,"someRemoteDirectory")
    If success <> 1
        Debug CkFtp2::ckLastErrorText(ftp)
        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    EndIf

    localFilename.s = "/temp/romeo.xml"
    remoteFilename.s = "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.
    task.i = CkFtp2::ckGetFileAsync(ftp,remoteFilename,localFilename)
    If CkFtp2::ckLastMethodSuccess(ftp) = 0
        Debug CkFtp2::ckLastErrorText(ftp)
        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    EndIf

    ; Before starting the task, tell it to keep an in-memory log of what would've been
    ; ProgressInfo callbacks.
    CkTask::setCkKeepProgressLog(task, 1)

    ; Schedule the task for running on the thread pool.  This changes the task's state
    ; from Inert to Live.
    success = CkTask::ckRun(task)
    If success <> 1
        Debug CkTask::ckLastErrorText(task)
        CkTask::ckDispose(task)

        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    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.
    curPctDone.i = 0
    name.s
    value.s

    While CkTask::ckFinished(task) <> 1

        If CkTask::ckPercentDone(task) <> curPctDone
            curPctDone = CkTask::ckPercentDone(task)
            Debug Str(curPctDone) + " percent done"
        EndIf

        ; Check the progress info log.
        ; Emit any log entries..
        While (CkTask::ckProgressLogSize(task) > 0)
            ; Get the 1st entry, emit it, and then remove it..
            name = CkTask::ckProgressInfoName(task,0)
            value = CkTask::ckProgressInfoValue(task,0)

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

            Debug name + ": " + value
            CkTask::ckRemoveProgressInfo(task,0)
        Wend

        ; Sleep 100 ms.
        CkTask::ckSleepMs(task,100)

    Wend

    ; Just in case there are any remaining entries...
    While (CkTask::ckProgressLogSize(task) > 0)
        ; Get the 1st entry, emit it, and then remove it..
        name = CkTask::ckProgressInfoName(task,0)
        value = CkTask::ckProgressInfoValue(task,0)
        Debug name + ": " + value
        CkTask::ckRemoveProgressInfo(task,0)
    Wend

    ; 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 CkTask::ckStatusInt(task) <> 7
        Debug "Task did not complete."
        Debug "task status: " + CkTask::ckStatus(task)
        CkTask::ckDispose(task)

        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    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.
    success = CkTask::ckGetResultBool(task)
    If success <> 1
        ; The task's ResultErrorText contains what would have been in the LastErrorText property had
        ; the GetFile method been called synchronously.
        Debug CkTask::ckResultErrorText(task)
    Else
        Debug "File downloaded asynchronously."
    EndIf

    CkTask::ckDispose(task)

    success = CkFtp2::ckDisconnect(ftp)


    CkFtp2::ckDispose(ftp)


    ProcedureReturn
EndProcedure