Board index » cppbuilder » How to properly wait for TCPPWebbrowser to be ready...

2007-01-29 09:40:03 PM
cppbuilder1
I've got everything working as it stands, however the program is
jumping to 99% cpu usage when it's waiting for the browser to
finish it's action. What I'd like to know, is how to wait without
being such a hog.
Here's the scenario:
I load up a web page, then using the IHTMLDocument3 I get
access to the controls I need by Id and modify them. When
that's done I use the click() function to submit the form.
The form is AJAX based, so I have to wait until that action is
completed before finally obtaining the source code from the
results div. In order to determine when to stop waiting I'm
checking the Style of another div to see if it's set back to hidden.
When the ajax portion is running the div is visible
(just says "Loading...please wait") and when it's not the div is
set to hidden.
So anyways, what I've got now for the loop is this:
WideString S;
do
{
TComInterface <IHTMLStyle>Style;
Element->get_style(&Style);
Style->get_display(&S);
}while(S == WideString(""));
I've also noticed the program appears to be locked up during this
loop. I added Application->ProcessMessages() to the loop but
that didn't help.
Thanks,
Tom
 

"Tom" < XXXX@XXXXX.COM >wrote in message
allow other threads to access the CPU.
loop. Maybe also Sleep() as well.
Also, your loop is checking for a blank "display" property, which may
not always be blank, even when the div disappears. It might be
getting set to "none" instead of "".
Amsuming the page is using an XMLHttpRequest object, you could try
hooking its onreadystatechange event, and then query its readystate
property when it changes to see when the tansmission is finished (or
just query the readystate in a loop instead of using an event). You
can also retrieve the data of the response, if needed.
processed.
Gambit
 

Remy,
moved the code from my test app into the actual program and it doesn't
seem to lock up nearly as bad.
I loop until it's set with something.
else is updated via AJAX.
Application->ProcessMessages() without having much improvement.
I think the event you mentioned above will work fine.
Thanks!
-Tom
 

{smallsort}

"Tom" < XXXX@XXXXX.COM >wrote in message
actual string "none" instead of an empty string "" when the div
becomes hidden. In any case, you said you are looping to wait for the
div to hide, but that is not what your code is actually showing. You
are waiting for the div to obtain any kind of style at all.
Gambit
 

to none. I suppose I could update the code, to be exact =)
-Tom