C++

Async Task Chain (another example)

See more Async Examples

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

#include <CkFtp2.h>
#include <CkTaskChain.h>
#include <CkTask.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    success = false;

    CkFtp2 ftp;

    ftp.put_Hostname("ftp.example.com");
    ftp.put_Username("login");
    ftp.put_Password("password");

    // Connect and login to the FTP server.
    success = ftp.Connect();
    if (success != true) {
        std::cout << ftp.lastErrorText() << "\r\n";
        return;
    }

    CkTaskChain taskChain;

    // Create a task to change to the remote directory where the file will be uploaded.
    CkTask *task = ftp.ChangeRemoteDirAsync("junk");
    if (ftp.get_LastMethodSuccess() == false) {
        std::cout << ftp.lastErrorText() << "\r\n";
        return;
    }

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

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

    task = ftp.PutFileAsync(localFilename,remoteFilename);
    if (ftp.get_LastMethodSuccess() == false) {
        std::cout << ftp.lastErrorText() << "\r\n";
        return;
    }

    // Add this task to the task chain.
    success = taskChain.Append(*task);
    delete 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.put_StopOnFailedTask(true);
    success = taskChain.Run();
    if (!success) {
        std::cout << taskChain.lastErrorText() << "\r\n";
        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.get_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.get_StatusInt() != 7) {
        std::cout << "Task did not complete." << "\r\n";
        std::cout << "task chain status: " << taskChain.status() << "\r\n";
        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..
    int numTasks = taskChain.get_NumTasks();
    int 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.
        std::cout << "task status: " << task->status() << "\r\n";
        std::cout << "task log: " << task->resultErrorText() << "\r\n";

        delete task;

        taskIdx = taskIdx + 1;
    }

    success = ftp.Disconnect();
    }