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 <C_CkFtp2.h>
#include <C_CkTaskChain.h>
#include <C_CkTask.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkFtp2 ftp;
    HCkTaskChain taskChain;
    HCkTask task;
    const char *localFilename;
    const char *remoteFilename;
    int numTasks;
    int taskIdx;

    success = FALSE;

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

    success = FALSE;

    ftp = CkFtp2_Create();

    CkFtp2_putHostname(ftp,"ftp.example.com");
    CkFtp2_putUsername(ftp,"login");
    CkFtp2_putPassword(ftp,"password");

    // Connect and login to the FTP server.
    success = CkFtp2_Connect(ftp);
    if (success != TRUE) {
        printf("%s\n",CkFtp2_lastErrorText(ftp));
        CkFtp2_Dispose(ftp);
        return;
    }

    taskChain = CkTaskChain_Create();

    // Create a task to change to the remote directory where the file will be uploaded.
    task = CkFtp2_ChangeRemoteDirAsync(ftp,"junk");
    if (CkFtp2_getLastMethodSuccess(ftp) == FALSE) {
        printf("%s\n",CkFtp2_lastErrorText(ftp));
        CkFtp2_Dispose(ftp);
        CkTaskChain_Dispose(taskChain);
        return;
    }

    // Add this task to the task chain.
    success = CkTaskChain_Append(taskChain,task);
    CkTask_Dispose(task);

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

    task = CkFtp2_PutFileAsync(ftp,localFilename,remoteFilename);
    if (CkFtp2_getLastMethodSuccess(ftp) == FALSE) {
        printf("%s\n",CkFtp2_lastErrorText(ftp));
        CkFtp2_Dispose(ftp);
        CkTaskChain_Dispose(taskChain);
        return;
    }

    // Add this task to the task chain.
    success = CkTaskChain_Append(taskChain,task);
    CkTask_Dispose(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.
    CkTaskChain_putStopOnFailedTask(taskChain,TRUE);
    success = CkTaskChain_Run(taskChain);
    if (!success) {
        printf("%s\n",CkTaskChain_lastErrorText(taskChain));
        CkFtp2_Dispose(ftp);
        CkTaskChain_Dispose(taskChain);
        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 (CkTaskChain_getFinished(taskChain) != TRUE) {

        // Sleep 100 ms.
        CkTaskChain_SleepMs(taskChain,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 (CkTaskChain_getStatusInt(taskChain) != 7) {
        printf("Task did not complete.\n");
        printf("task chain status: %s\n",CkTaskChain_status(taskChain));
        CkFtp2_Dispose(ftp);
        CkTaskChain_Dispose(taskChain);
        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..
    numTasks = CkTaskChain_getNumTasks(taskChain);
    taskIdx = 0;

    while ((taskIdx < numTasks)) {

        task = CkTaskChain_GetTask(taskChain,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.
        printf("task status: %s\n",CkTask_status(task));
        printf("task log: %s\n",CkTask_resultErrorText(task));

        CkTask_Dispose(task);

        taskIdx = taskIdx + 1;
    }

    success = CkFtp2_Disconnect(ftp);


    CkFtp2_Dispose(ftp);
    CkTaskChain_Dispose(taskChain);

    }