Can I cancel a running server page from the browser?

[Larry Woods]

I have a server page that has served an HTML page with a "Cancel" button on
it, BUT this server page has not completed and is running a 15-30 second
process before it completes. I want the browser user to be able to
terminate the page before the server process has finished. What I tried was
an onClick event that issued a "location.href. .." in hopes that this would
load this referenced page, etc. but I have found that the browser waits
until the server process had compled before executing the "location.href" .
Is there some way that I can "signal" the server to stop processing so that
I can go to the "location.h ref" page; or is there some other way?

TIA,

Larry Woods

[Dave Anderson]

"Larry Woods" wrote:

I have a server page that has served an HTML page with a "Cancel"
button on it, BUT this server page has not completed and is running
a 15-30 second process before it completes. I want the browser user
to be able to terminate the page before the server process has
finished...
...Is there some way that I can "signal" the server to stop
processing so that I can go to the "location.h ref" page; or is there
some other way?

You cannot directly cancel the request. The best you can do is have the ASP
process constantly monitor some independent entity (a session variable or a
record in a DB, for example), continuing only if some prearranged condition
is met. The cancel request would still be independent of the original
request, but this should be possible in principle.
--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message. Use
of this email address implies consent to these terms. Please do not contact
me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.

[Larry Woods]

Thanks, Dave.

What would be the best way to set a Session variable for the browser? A
popup window ( 0 x 0 )?

TIA,

Larry

"Dave Anderson" <GT**********@s pammotel.com> wrote in message
news:Or******** ******@TK2MSFTN GP10.phx.gbl...

"Larry Woods" wrote:

I have a server page that has served an HTML page with a "Cancel"
button on it, BUT this server page has not completed and is running
a 15-30 second process before it completes. I want the browser user
to be able to terminate the page before the server process has
finished...
...Is there some way that I can "signal" the server to stop
processing so that I can go to the "location.h ref" page; or is there
some other way?
You cannot directly cancel the request. The best you can do is have the

ASP process constantly monitor some independent entity (a session variable or a record in a DB, for example), continuing only if some prearranged condition is met. The cancel request would still be independent of the original
request, but this should be possible in principle.
--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message. Use of this email address implies consent to these terms. Please do not contact me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.

[Aaron Bertrand - MVP]

Use a hidden frame.
http://www.aspfaq.com/2001
http://www.aspfaq.com/2281
"Larry Woods" <la***@lwoods.c om> wrote in message
news:OD******** ******@TK2MSFTN GP12.phx.gbl...

Thanks, Dave.

What would be the best way to set a Session variable for the browser? A
popup window ( 0 x 0 )?

TIA,

Larry

"Dave Anderson" <GT**********@s pammotel.com> wrote in message
news:Or******** ******@TK2MSFTN GP10.phx.gbl...

"Larry Woods" wrote:

I have a server page that has served an HTML page with a "Cancel"
button on it, BUT this server page has not completed and is running
a 15-30 second process before it completes. I want the browser user
to be able to terminate the page before the server process has
finished...
...Is there some way that I can "signal" the server to stop
processing so that I can go to the "location.h ref" page; or is there
some other way?
You cannot directly cancel the request. The best you can do is have the

ASP

process constantly monitor some independent entity (a session variable

or a

record in a DB, for example), continuing only if some prearranged

condition

is met. The cancel request would still be independent of the original
request, but this should be possible in principle.
--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message.

Use

of this email address implies consent to these terms. Please do not

contact

me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.

[Michael D. Kersey]

Larry Woods wrote:

I have a server page that has served an HTML page with a "Cancel" button on
it, BUT this server page has not completed and is running a 15-30 second
process before it completes.
Long-running processes are not good for web servers. You should write
this application a different way. See
http://www.google.com/groups?hl=en&l...40TK2MSFTNGP09
for a better way.
I want the browser user to be able to
terminate the page before the server process has finished.

Educate the user about the browser's "Stop" button. Alternatively the
user can click on another URL, select a bookmark, or enter a new URL.
When the Stop button is pressed, the TCP connection is reset and the
connection closed between client browser and server. Any queued output
will be discarded by whichever party (client, server or proxy agent) is
holding it.

Good Luck,
Michael D. Kersey

[Larry Woods]

The application is searching the Web using a second server; i.e., the ASP
server XMLHTTPs to a second server which is performing the searches.
USUALLY the second server responds in a fairly short time, but once in a
while it will be quite a while. It is possible that the user will want to
"bail out". Within the ASP server, I can abort the XMLHTTP session with the
second server if I know that I am to do it. We have implemented some
safeguards such as having the second server time out, and also having the
ASP server monitor the situation but there is STILL the possibility that the
user wants to terminate the "Please Wait" page.

Larry

"Dave Anderson" <GT**********@s pammotel.com> wrote in message
news:%2******** ********@TK2MSF TNGP12.phx.gbl. ..

"Larry Woods" wrote:

What would be the best way to set a Session variable for the
browser? A popup window ( 0 x 0 )?
I should clarify my comments. Although I outlined a possible solution, it

is not one I recommend. You would be best served by designing processes that do not need to be interrupted, as this other technique could be far more
demanding on resources than you anticipate.

What are you trying to accomplish, and why do you need to stop a process
once it is underway?
--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message. Use of this email address implies consent to these terms. Please do not contact me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.

[Larry Woods]

That is a good idea, Aaron, but this solution is "IE only" and even though I
wish that I could depend on that this site is a public site so I can't
assume IE. Any other suggestions?

TIA,

Larry

"Aaron Bertrand - MVP" <aa***@TRASHasp faq.com> wrote in message
news:eE******** ******@TK2MSFTN GP10.phx.gbl...

Use a hidden frame.
http://www.aspfaq.com/2001
http://www.aspfaq.com/2281
"Larry Woods" <la***@lwoods.c om> wrote in message
news:OD******** ******@TK2MSFTN GP12.phx.gbl...

Thanks, Dave.

What would be the best way to set a Session variable for the browser? A
popup window ( 0 x 0 )?

TIA,

Larry

"Dave Anderson" <GT**********@s pammotel.com> wrote in message
news:Or******** ******@TK2MSFTN GP10.phx.gbl...

"Larry Woods" wrote:
>
> I have a server page that has served an HTML page with a "Cancel"
> button on it, BUT this server page has not completed and is running
> a 15-30 second process before it completes. I want the browser user
> to be able to terminate the page before the server process has
> finished...
> ...Is there some way that I can "signal" the server to stop
> processing so that I can go to the "location.h ref" page; or is there
> some other way?

You cannot directly cancel the request. The best you can do is have

the ASP

process constantly monitor some independent entity (a session variable or

a

record in a DB, for example), continuing only if some prearranged

condition

is met. The cancel request would still be independent of the original
request, but this should be possible in principle.
--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per

message. Use

of this email address implies consent to these terms. Please do not

contact

me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.

[Larry Woods]

I'll look into the Google suggestion.

I want the user to terminate the page, but not the present session. In
another response to my question I have explained my application. The delay
is a possible looooong Web search by the server.

TIA,

Larry

"Michael D. Kersey" <md******@hal-pc.org> wrote in message
news:3F******** *******@hal-pc.org...

Larry Woods wrote:

I have a server page that has served an HTML page with a "Cancel" button on it, BUT this server page has not completed and is running a 15-30 second
process before it completes.
Long-running processes are not good for web servers. You should write
this application a different way. See

http://www.google.com/groups?hl=en&l...40TK2MSFTNGP09 for a better way.

I want the browser user to be able to
terminate the page before the server process has finished.

Educate the user about the browser's "Stop" button. Alternatively the
user can click on another URL, select a bookmark, or enter a new URL.
When the Stop button is pressed, the TCP connection is reset and the
connection closed between client browser and server. Any queued output
will be discarded by whichever party (client, server or proxy agent) is
holding it.

Good Luck,
Michael D. Kersey

[Bob Barrows]

Well, you can use xmlhttp to run a second server-side page that sets a
session cancel variable to true can't you?

Bob

Larry Woods wrote:

The application is searching the Web using a second server; i.e., the
ASP server XMLHTTPs to a second server which is performing the
searches. USUALLY the second server responds in a fairly short time,
but once in a while it will be quite a while. It is possible that
the user will want to "bail out". Within the ASP server, I can abort
the XMLHTTP session with the second server if I know that I am to do
it. We have implemented some safeguards such as having the second
server time out, and also having the ASP server monitor the situation
but there is STILL the possibility that the user wants to terminate
the "Please Wait" page.

Larry

"Dave Anderson" <GT**********@s pammotel.com> wrote in message
news:%2******** ********@TK2MSF TNGP12.phx.gbl. ..

"Larry Woods" wrote:

What would be the best way to set a Session variable for the
browser? A popup window ( 0 x 0 )?

I should clarify my comments. Although I outlined a possible
solution, it is not one I recommend. You would be best served by
designing processes that do not need to be interrupted, as this
other technique could be far more demanding on resources than you
anticipate.

What are you trying to accomplish, and why do you need to stop a
process once it is underway?
--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per
message. Use of this email address implies consent to these terms.
Please do not contact me directly or ask me to contact you directly
for assistance. If your question is worth asking, it's worth posting.

[Aaron Bertrand - MVP]

> That is a good idea, Aaron, but this solution is "IE only"

What? You can't use a hidden frame like this, in other browsers:

<frameset rows="99%, 1%">
<frame ...
<frame ...
</frameset>

???