Quiz #1: Will this code work correctly and why?

[Erel]

This question is about HttpUtils2: HttpUtils2 - Web services are now even simpler

In some cases we need to modify the request. For example we may need to add a header to the message before it is sent.

Dim Job As HttpJob
Job.Initialize("Job", Me)
Job.Download("http://www.b4x.com")
' ****** The header is set after Download is called ?!
Job.GetRequest.SetHeader("User-Agent", "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)")

Note that it is not possible to call Job.GetRequest before Job.Download as the request is initialized in Job.Download.

Does it work?
Why?

 

[keirS]

Surely that depends on the status of HTTPutils2 service? My guess is that it will not work if the service is active but it could stand a chance of working if the service has to be started.

 

[thedesolatesoul]

It works because CallSubDelayed2 is used to start the service and call a sub. Since CallSubDelayed uses the message queue, the service code/sub will not be executed until the current thread exits, which will exit after SetHeader is set, and whenever the calling sub completes.
EDIT: Ofcourse, I didnt know this before to ever use it. Good technique, but not so straight forward for readability.

 

[Erel]

:sign0098:

You are correct.

This is a side effect of CallSubDelayed. CallSubDelayed is used here to call the service from the class.

That was quick. Next time I will think of a more challenging question...

 

[thedesolatesoul]

:sign0098:

You are correct.

This is a side effect of CallSubDelayed. CallSubDelayed is used here to call the service from the class.

That was quick. Next time I will think of a more challenging question...

This will be fun :icon_clap: