DataFlex

Async Methods Returning an String

See more Async Examples

Demonstrates how to call an asynchronous method that returns a string. This example sends an HTTPS GET request to a URL and gets the HTML response. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoHttp
    Variant vTask
    Handle hoTask
    String sHtml
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    Get ComQuickGetStrAsync Of hoHttp "https://www.chilkatsoft.com/helloWorld.html" To vTask
    If (IsComObject(vTask)) Begin
        Get Create (RefClass(cComChilkatTask)) To hoTask
        Set pvComObject Of hoTask To vTask
    End
    Get ComLastMethodSuccess Of hoHttp To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Start the background task.
    Get ComRun Of hoTask To iSuccess
    If (Not iSuccess) Begin
        Get ComLastErrorText Of hoTask To sTemp1
        Showln sTemp1
        Send Destroy of hoTask
        Procedure_Return
    End

    // The application is now free to do anything else

    // For this example, we'll simply sleep and periodically
    // check to see if the HTTPS GET if finished.
    While ((ComFinished(hoTask)) <> True)
        // Sleep 100 ms.
        Send ComSleepMs To hoTask 100
    Loop

    // 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:
    Get ComStatusInt Of hoTask To iTemp1
    If (iTemp1 <> 7) Begin
        Showln "Task did not complete."
        Get ComStatus Of hoTask To sTemp1
        Showln "task status: " sTemp1
        Send Destroy of hoTask
        Procedure_Return
    End

    // The QuickGetStr method returns a string.  Therefore, after the task is finished,
    // we can get the string result by calling GetResultString.  This is the return value had
    // we called QuickGetStr synchronously.
    Get ComGetResultString Of hoTask To sHtml

    Showln sHtml

    Send Destroy of hoTask


End_Procedure