(Chilkat2-Python) Async Task Chain (another example)

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

Chilkat2 Python Downloads install with pip pip3 install chilkat2 or download... Python Module for Windows, Linux, Alpine Linux, MacOS, Solaris

import sys
import chilkat2

# All Chilkat classes can be unlocked at once at the beginning of a program
# by calling UnlockBundle.  It requires a Bundle unlock code.
chilkatGlob = chilkat2.Global()
success = chilkatGlob.UnlockBundle("Anything for 30-day trial.")
if (success != True):
    print(chilkatGlob.LastErrorText)
    sys.exit()

ftp = chilkat2.Ftp2()

ftp.Hostname = "ftp.someFtpServer.com"
ftp.Username = "****"
ftp.Password = "****"

# Connect and login to the FTP server.
success = ftp.Connect()
if (success != True):
    print(ftp.LastErrorText)
    sys.exit()

taskChain = chilkat2.TaskChain()

# Create a task to change to the remote directory where the file will be uploaded.
# task is a CkTask
task = ftp.ChangeRemoteDirAsync("junk")
if (ftp.LastMethodSuccess == False):
    print(ftp.LastErrorText)
    sys.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 is a CkTask
task = ftp.PutFileAsync(localFilename,remoteFilename)
if (ftp.LastMethodSuccess == False):
    print(ftp.LastErrorText)
    sys.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 (not success):
    print(taskChain.LastErrorText)
    sys.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 != 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 != 7):
    print("Task did not complete.")
    print("task chain status: " + taskChain.Status)
    sys.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 < numTasks) :

    # task is a CkTask
    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.
    print("task status: " + task.Status)
    print("task log: " + task.ResultErrorText)

    taskIdx = taskIdx + 1

success = ftp.Disconnect()