Node.js

Async Task Chain (another example)

See more Async Examples

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

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

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

    success = false;

    var ftp = new 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 !== true) {
        console.log(ftp.LastErrorText);
        return;
    }

    var taskChain = new chilkat.TaskChain();

    //  Create a task to change to the remote directory where the file will be uploaded.
    // task: Task
    var task = ftp.ChangeRemoteDirAsync("junk");
    if (ftp.LastMethodSuccess == false) {
        console.log(ftp.LastErrorText);
        return;
    }

    //  Add this task to the task chain.
    success = taskChain.Append(task);

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

    task = ftp.PutFileAsync(localFilename,remoteFilename);
    if (ftp.LastMethodSuccess == false) {
        console.log(ftp.LastErrorText);
        return;
    }

    //  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) {
        console.log(taskChain.LastErrorText);
        return;
    }

    //  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) {
        console.log("Task did not complete.");
        console.log("task chain status: " + taskChain.Status);
        return;
    }

    //  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..
    var numTasks = taskChain.NumTasks;
    var taskIdx = 0;

    while ((taskIdx < 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.
        console.log("task status: " + task.Status);
        console.log("task log: " + task.ResultErrorText);

        taskIdx = taskIdx+1;
    }

    success = ftp.Disconnect();

}

chilkatExample();