(Tcl) 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.

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load ./chilkat.dll

# All Chilkat classes can be unlocked at once at the beginning of a program
# by calling UnlockBundle.  It requires a Bundle unlock code.
set chilkatGlob [new_CkGlobal]

set success [CkGlobal_UnlockBundle $chilkatGlob "Anything for 30-day trial."]
if {$success != 1} then {
    puts [CkGlobal_lastErrorText $chilkatGlob]
    delete_CkGlobal $chilkatGlob
    exit
}

set http [new_CkHttp]

# 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.
# task is a CkTask
set task [CkHttp_QuickGetObjAsync $http "https://stackexchange.com"]
if {[CkHttp_get_LastMethodSuccess $http] != 1} then {
    puts [CkHttp_lastErrorText $http]
    delete_CkGlobal $chilkatGlob
    delete_CkHttp $http
    exit
}

# Schedule the task for running on the thread pool.  This changes the task's state
# from Inert to Live.
set success [CkTask_Run $task]
if {$success != 1} then {
    puts [CkTask_lastErrorText $task]
    delete_CkTask $task

    delete_CkGlobal $chilkatGlob
    delete_CkHttp $http
    exit
}

# 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 {[CkTask_get_Finished $task] != 1} {

    # Sleep 100 ms.
    CkTask_SleepMs $task 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 {[CkTask_get_StatusInt $task] != 7} then {
    puts "Task did not complete."
    puts "task status: [CkTask_status $task]"
    delete_CkTask $task

    delete_CkGlobal $chilkatGlob
    delete_CkHttp $http
    exit
}

# 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.
set resp [new_CkHttpResponse]

set success [CkHttpResponse_LoadTaskResult $resp $task]
if {$success != 1} then {
    puts [CkHttpResponse_lastErrorText $resp]
    delete_CkTask $task

    delete_CkGlobal $chilkatGlob
    delete_CkHttp $http
    delete_CkHttpResponse $resp
    exit
}

delete_CkTask $task

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

puts "status code: [CkHttpResponse_get_StatusCode $resp]"
puts "response header: [CkHttpResponse_header $resp]"

# ..

delete_CkGlobal $chilkatGlob
delete_CkHttp $http
delete_CkHttpResponse $resp