(PowerShell) Async Task Chain (another example)

Demonstrates using a task chain to run a sequence of FTP tasks asynchronously.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# All Chilkat classes can be unlocked at once at the beginning of a program
# by calling UnlockBundle.  It requires a Bundle unlock code.
$chilkatGlob = New-Object Chilkat.Global
$success = $chilkatGlob.UnlockBundle("Anything for 30-day trial.")
if ($success -ne $true) {
    $($chilkatGlob.LastErrorText)
    exit
}

$ftp = New-Object Chilkat.Ftp2

$ftp.Hostname = "ftp.example.com"
$ftp.Username = "login"
$ftp.Password = "password"

# Connect and login to the FTP server.
$success = $ftp.Connect()
if ($success -ne $true) {
    $($ftp.LastErrorText)
    exit
}

$taskChain = New-Object Chilkat.TaskChain

# Create a task to change to the remote directory where the file will be uploaded.
$task = $ftp.ChangeRemoteDirAsync("junk")
if ($ftp.LastMethodSuccess -eq $false) {
    $($ftp.LastErrorText)
    exit
}

# Add this task to the task chain.
$success = $taskChain.Append($task)

# Create a task to upload a file.
$localFilename = "c:/temp/hamlet.xml"
$remoteFilename = "hamlet.xml"

$task = $ftp.PutFileAsync($localFilename,$remoteFilename)
if ($ftp.LastMethodSuccess -eq $false) {
    $($ftp.LastErrorText)
    exit
}

# Add this task to the task chain.
$success = $taskChain.Append($task)

# Start the task chain running in a background thread.
# Each task is run one after the other (on the same background thread) until all tasks have completed.
# The task chain will stop at the first task that fails.
$taskChain.StopOnFailedTask = $true
$success = $taskChain.Run()
if (!$success) {
    $($taskChain.LastErrorText)
    exit
}

# The application is now free to do anything else
# while the FTP commands are being run...

# For this example, we'll simply sleep and periodically
# check to see if the taskchain if finished. 
while ($taskChain.Finished -ne $true) {

    # Sleep 100 ms.
    $taskChain.SleepMs(100)

}

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

# If the task chain "completed", then it ran to completion.  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 ($taskChain.StatusInt -ne 7) {
    $("Task did not complete.")
    $("task chain status: " + $taskChain.Status)
    exit
}

# If we got to this point, the ChangeRemoteDir and PutFile were successful.
# We can visually verify by examining the LastErrorText that was recorded for each
# of these method calls..
$numTasks = $taskChain.NumTasks
$taskIdx = 0

while (($taskIdx -lt $numTasks)) {

    $task = $taskChain.GetTask($taskIdx)

    # Examine the status of this task, and the ResultErrorText
    # (the ResultErrorText is the ftp.LastErrorText captured for FTP method called by the task).
    # Everything should indicate success.
    $("task status: " + $task.Status)
    $("task log: " + $task.ResultErrorText)

    $taskIdx = $taskIdx + 1
}

$success = $ftp.Disconnect()