(MFC) Getting the HTTP Response after an Asynchronous HTTP Request Completes

Some HTTP methods return an HTTP response object. This example demonstrates how to obtain the HTTP response object for such a method when calling asynchronously.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkGlobal.h>
#include <CkHttp.h>
#include <CkTask.h>
#include <CkHttpResponse.h>

void ChilkatSample(void)
    {
    CkString strOut;

    //  All Chilkat classes can be unlocked at once at the beginning of a program
    //  by calling UnlockBundle.  It requires a Bundle unlock code.
    CkGlobal chilkatGlob;
    bool success = chilkatGlob.UnlockBundle("Anything for 30-day trial.");
    if (success != true) {
        strOut.append(chilkatGlob.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkHttp http;

    //  Call the async version of the QuickGetObj method to return a task object.
    //  The task object is loaded, but is in the Inert state -- meaning it is
    //  not yet scheduled to run on Chilkat's background thread pool.
    CkTask *task = http.QuickGetObjAsync("https://stackexchange.com");
    if (http.get_LastMethodSuccess() != true) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Schedule the task for running on the thread pool.  This changes the task's state
    //  from Inert to Live.
    success = task->Run();
    if (success != true) {
        strOut.append(task->lastErrorText());
        strOut.append("\r\n");
        delete task;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  The application is now free to do anything else
    //  while the HTML page is being downloaded.

    //  For this example, we'll simply sleep and periodically
    //  check to see if the QuickGetObjAsync if finished.
    while (task->get_Finished() != true) {

        //  Sleep 100 ms.
        task->SleepMs(100);

    }

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

    //  If the task was "canceled", it was canceled prior to actually starting.  This could
    //  happen if the task was canceled while waiting in a thread pool queue to be scheduled by Chilkat's
    //  background thread pool scheduler.

    //  If the task was "aborted", it indicates that it was canceled while running in a background thread.
    //  The ResultErrorText will likely indicate that the task was aborted.

    //  If the task "completed", then it ran to completion, but the actual success/failure of the method
    //  is determined by the result obtained via a GetResult* method.  (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 (task->get_StatusInt() != 7) {
        strOut.append("Task did not complete.");
        strOut.append("\r\n");
        strOut.append("task status: ");
        strOut.append(task->status());
        strOut.append("\r\n");
        delete task;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  The synchronous call to QuickGetObj would return an HTTP response object.  To get this
    //  response object for the async call, we instantiate a new/empty HTTP response object,
    //  and then load it from the completed task.
    CkHttpResponse resp;

    success = resp.LoadTaskResult(*task);
    if (success != true) {
        strOut.append(resp.lastErrorText());
        strOut.append("\r\n");
        delete task;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    delete task;

    //  Now that we have the response, we can get all of the information:

    strOut.append("status code: ");
    strOut.appendInt(resp.get_StatusCode());
    strOut.append("\r\n");
    strOut.append("response header: ");
    strOut.append(resp.header());
    strOut.append("\r\n");

    //  ...


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }