(Xojo Plugin) Async FTP Progress Info

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

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

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

Dim ftp As New Chilkat.Ftp2

ftp.Hostname = "ftp.someFtpServer.com"
Dim success As Boolean
success = ftp.ConnectOnly()
If (success <> True) Then
    System.DebugLog(ftp.LastErrorText)
    Return
End If

ftp.Username = "myLogin"
ftp.Password = "myPassword"
success = ftp.LoginAfterConnectOnly()
If (success <> True) Then
    System.DebugLog(ftp.LastErrorText)
    Return
End If

// 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 = ftp.ChangeRemoteDir("someRemoteDirectory")
If (success <> True) Then
    System.DebugLog(ftp.LastErrorText)
    Return
End If

Dim localFilename As String
localFilename = "/temp/romeo.xml"
Dim remoteFilename As String
remoteFilename = "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.
Dim task As Chilkat.Task
task = ftp.GetFileAsync(remoteFilename,localFilename)
If (ftp.LastMethodSuccess = False) Then
    System.DebugLog(ftp.LastErrorText)
    Return
End If

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

// Schedule the task for running on the thread pool.  This changes the task's state
// from Inert to Live.
success = task.Run()
If (success <> True) Then
    System.DebugLog(task.LastErrorText)

    Return
End If

// 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.
Dim curPctDone As Int32
curPctDone = 0
Dim name As String
Dim value As String

While task.Finished <> True

    If (task.PercentDone <> curPctDone) Then
        curPctDone = task.PercentDone
        System.DebugLog(Str(curPctDone) + " percent done")
    End If

    // Check the progress info log.
    // Emit any log entries..
    While (task.ProgressLogSize > 0)
        // Get the 1st entry, emit it, and then remove it..
        name = task.ProgressInfoName(0)
        value = task.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"

        System.DebugLog(name + ": " + value)
        task.RemoveProgressInfo 0
    Wend

    // Sleep 100 ms.
    task.SleepMs 100

Wend

// Just in case there are any remaining entries...
While (task.ProgressLogSize > 0)
    // Get the 1st entry, emit it, and then remove it..
    name = task.ProgressInfoName(0)
    value = task.ProgressInfoValue(0)
    System.DebugLog(name + ": " + value)
    task.RemoveProgressInfo 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 (task.StatusInt <> 7) Then
    System.DebugLog("Task did not complete.")
    System.DebugLog("task status: " + task.Status)

    Return
End If

// 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 = task.GetResultBool()
If (success <> True) Then
    // The task's ResultErrorText contains what would have been in the LastErrorText property had
    // the GetFile method been called synchronously.
    System.DebugLog(task.ResultErrorText)
Else
    System.DebugLog("File downloaded asynchronously.")
End If

success = ftp.Disconnect()