(SQL Server) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- All Chilkat classes can be unlocked at once at the beginning of a program
    -- by calling UnlockBundle.  It requires a Bundle unlock code.
    DECLARE @chilkatGlob int
    -- Use "Chilkat_9_5_0.Global" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Global', @chilkatGlob OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int
    EXEC sp_OAMethod @chilkatGlob, 'UnlockBundle', @success OUT, 'Anything for 30-day trial.'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @chilkatGlob, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @chilkatGlob
        RETURN
      END

    DECLARE @http int
    -- Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT

    -- 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.
    DECLARE @task int
    EXEC sp_OAMethod @http, 'QuickGetObjAsync', @task OUT, 'https://stackexchange.com'
    EXEC sp_OAGetProperty @http, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @chilkatGlob
        EXEC @hr = sp_OADestroy @http
        RETURN
      END

    -- Schedule the task for running on the thread pool.  This changes the task's state
    -- from Inert to Live.
    EXEC sp_OAMethod @task, 'Run', @success OUT
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @task, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @task

        EXEC @hr = sp_OADestroy @chilkatGlob
        EXEC @hr = sp_OADestroy @http
        RETURN
      END

    -- 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.
    EXEC sp_OAGetProperty @task, 'Finished', @iTmp0 OUT
    WHILE @iTmp0 <> 1
      BEGIN

        -- Sleep 100 ms.
        EXEC sp_OAMethod @task, 'SleepMs', NULL, 100

      END

    -- 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:
    EXEC sp_OAGetProperty @task, 'StatusInt', @iTmp0 OUT
    IF @iTmp0 <> 7
      BEGIN

        PRINT 'Task did not complete.'

        EXEC sp_OAGetProperty @task, 'Status', @sTmp0 OUT
        PRINT 'task status: ' + @sTmp0
        EXEC @hr = sp_OADestroy @task

        EXEC @hr = sp_OADestroy @chilkatGlob
        EXEC @hr = sp_OADestroy @http
        RETURN
      END

    -- 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.
    DECLARE @resp int
    -- Use "Chilkat_9_5_0.HttpResponse" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.HttpResponse', @resp OUT

    EXEC sp_OAMethod @resp, 'LoadTaskResult', @success OUT, @task
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @resp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @task

        EXEC @hr = sp_OADestroy @chilkatGlob
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @resp
        RETURN
      END

    EXEC @hr = sp_OADestroy @task

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


    EXEC sp_OAGetProperty @resp, 'StatusCode', @iTmp0 OUT
    PRINT 'status code: ' + @iTmp0

    EXEC sp_OAGetProperty @resp, 'Header', @sTmp0 OUT
    PRINT 'response header: ' + @sTmp0

    -- ..

    EXEC @hr = sp_OADestroy @chilkatGlob
    EXEC @hr = sp_OADestroy @http
    EXEC @hr = sp_OADestroy @resp


END
GO