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)>To:
l.org=20
href=3D"mailto:pgsql-php@postgresql.org">pgsql-php@postgresq l.org
IV>
Sent: Tuesday, November 18, 2003 1=
0:33=20
AM
Subject: [PHP] Cancel a query when=
user=20
leaves a web page
Hi all,
I have a small problem. Is it possible to c=
ancel=20
a running query when a person leave or pressed the stop button in my web=
=20
page.
I've been thinking about mixing php and javascript. Is this =
the=20
best way to go about it?
basic out line of my=20
code:
<html><head>....stuff....</head>
<body&g=
t;...stuff
<?php
=20
$connection =3D pg_connect(host, dbname, user);
=
=20
pg_send_query($connection, "SELECT * FROM blah");
&nbs=
p; //=20
collect the results and display=20
etc..
?>
</body></html>
The query can take some=
=20
time.
And when the page is left the query is still running on=20
postmaster.
Have tried
<?php
include=
=20
"functions.php";
$connection =3D pg_connect(host, d=
bname,=20
user);
?>
<html><body=20
onunload(<?close_connection($connection)?>)>
<?php
&nbs=
p; =20
echo $connection;
pg_send_query($connection, "SELEC=
T *=20
FROM blah");
// collect the results and display=
=20
etc..
?>
</body></html>
The function,=20
close_connection($connection), is defined in the include file, which is t=
he=20
connection is busy, cancels the query and closes the connection.
T=
his=20
gives the following error:
Resource id #1
Warning:=20
pg_send_query(): 1 is not a valid PostgreSQL link resource in=20
/home/fauxn/public_html/singleAArepeats/test.php on line=20
11
Any suggestions welcome.
Many thanks
RE class=3Dmoz-signature cols=3D"72">--=20
Noel Faux
Department of Biochemistry and Molecular Biology
Monash University
Clayton 3168
Victoria
Australia
------=_NextPart_000_009D_01C3AF07.CA3727B0--
Re: Cancel a query when user leaves a web page
am 16.12.2003 08:58:17 von Noel
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Hi all,
Sorry for the delayed response, I've added both Hayat's and ljb220's
suggestions.
I've tried both, but still having problems.
Code:
//----------------------
test.php
global $connection;
$connection = pg_connect("host=localhost dbname=test user=test");
echo $connection." connection
";
echo pg_connection_status($connection)." status
";
pg_send_query($connection, "SELECT COUNT(id) FROM test"); //
expected to take ~2min enough time to press stop
echo pg_connection_busy($connection)." busy
";
$res = pg_get_result($connection);
echo pg_num_rows($res)." # rows
";
echo $GLOBALS["connection"]." GLOBALS
";
?>
//--------------------------------------
close.php
echo "closing connection
";
$f = fopen("/home/xxx/log","w"); // log file to trace the code etc...
fwrite($f,"new page\n");
fclose($f);
close_con();
echo "closed";
echo "";
?>
//--------------------------------
functions.php
/* when the page is exited, if the connection is not null, cancel and
sql statements and
close the database connection */
function close_con() {
$f = fopen("/home/xxx/log","w"); // log file to trace the code
etc...
$connection = $GLOBALS["connection"];
fwrite($f,"Closing connection\n");
$status = pg_connection_status($connection);
fwrite($f, $status." status\n");
if($status == 0){// connected
fwrite($f, "connected\n");
if(pg_connection_busy($connection)) {// busy so cancel last
query
fwrite($f, "connection busy\n");
pg_cancel_query($connection);
fwrite($f, "query killed\n");
}
// close connection
pg_close($connection);
fwrite($f, "connection closed");
}
else {
fwrite($f, "not connected\n");
}
fclose($f);
}
?>
With this set up, the user enters test.php. Stops before the query
finishes. It should call leave(). However, this dose not happen. I
believe it is because the script has not finished and passed the page
text to the browser (pls correct me if I'm wrong), until php has
finished processing it.
I've tried using register_shutdown_function() as:
test.php
global $connection;
$connection = pg_connect("host=localhost dbname=test user=test");
register_shutdown_function("close_con");
echo $connection." connection
";
echo pg_connection_status($connection)." status
";
pg_send_query($connection, "SELECT COUNT(id) FROM test");
echo pg_connection_busy($connection)." busy
";
$res = pg_get_result($connection);
echo pg_num_rows($res)." # rows
";
echo $GLOBALS["connection"]." GLOBALS
";
?>
The functions.php as above.
This also dose not work as, " The registered shutdown functions are
called after the request has been completed" (from
http://au2.php.net/manual/en/function.register-shutdown-func tion.php ).
I'm interpreting that as, any functions in the list will not be
called until the pg_send_query() or the pg_get_result(), not sure which,
returns. Then close_con() from functions.php is called via
register_shutdown_function(). Thus I'm unable to cancel the query :(
Any comments, suggestions or work arounds would be greatly appreciated.
I'm using PHP 4.2.3
Cheers
Noel
//---------------------------------------------------------- -------------------
Muhyiddin A.M Hayat wrote:
> )>
>
> onunload above can't call function from PHP, but it called from
> javascript, you can create javascript function to call PHP
> function/file that you wanna PHP do
>
>
> // close_connection.php
> include('connection.php');
> global $connection;
>
> function close_connection($connection){
> // close_connection here
> // .....
> // .....
> // .....
>
> }
>
> close_connection($connection);
> echo "";
> ?>
>
> ---------
>
>
>
>
>
>
>
>
>
>
//----------------------------------------
ljb wrote:
noel.faux@med.monash.edu.au wrote:
>I have a small problem. Is it possible to cancel a running query when a
>person leave or pressed the stop button in my web page.
>...
>Have tried
>
> include "functions.php";
> $connection = pg_connect(host, dbname, user);
>?>
>)>
>
>
> ...
>
> This will never work, as you found. The Javascript action is client-side
> and PHP is server-side.
>
> Try using register_shutdown_function() to register a function which will
> call pg_cancel_query(). As long as PHP isn't ignoring user aborts (see
> ignore_user_abort()), your query will be cancelled when the user hits STOP.
> Another way is to ignore user aborts, and while waiting for the
> asynchronous query to finish, keep calling connection_aborted() to see if
> you are still connected to the user; if not you cancel the query and exit.
--
Noel Faux
Department of Biochemistry and Molecular Biology
Monash University
Clayton 3168
Victoria
Australia
--Boundary_(ID_guCDxg5vhcnlCQv3p5oAOw)
Content-type: text/html; charset=us-ascii
Content-transfer-encoding: 7BIT
Hi all,
Sorry for the delayed response, I've added both Hayat's and ljb220's
suggestions.
I've tried both, but still having problems.
Code:
//----------------------
test.php
<html>
<script language="JavaScript">
<!-- Begin
function leave() {
window.open('close.php','','toolbar=no,menubar=no,location=n o,height=10,width=10','');
}
// end -->
</script>
<body onunload = 'leave()'>
<?php include "functions.php";
global $connection;
$connection = pg_connect("host=localhost dbname=test user=test");
echo $connection." connection <br>";
echo pg_connection_status($connection)." status<br>";
pg_send_query($connection, "SELECT COUNT(id) FROM test"); //
expected to take ~2min enough time to press stop
echo pg_connection_busy($connection)." busy<br>";
$res = pg_get_result($connection);
echo pg_num_rows($res)." # rows<br>";
echo $GLOBALS["connection"]." GLOBALS<br>";
?>
</body></html>
//--------------------------------------
close.php
<?php include "functions.php";
echo "closing connection<br>";
$f = fopen("/home/xxx/log","w"); // log file to trace the code
etc...
fwrite($f,"new page\n");
fclose($f);
close_con();
echo "closed";
echo "<script>window.close();</script>";
?>
//--------------------------------
functions.php
<?php
/* when the page is exited, if the connection is not null, cancel and
sql statements and
close the database connection */
function close_con() {
$f = fopen("/home/xxx/log","w"); // log file to trace the code
etc...
$connection = $GLOBALS["connection"];
fwrite($f,"Closing connection\n");
$status = pg_connection_status($connection);
fwrite($f, $status." status\n");
if($status == 0){// connected
fwrite($f, "connected\n");
if(pg_connection_busy($connection)) {// busy so cancel last
query
fwrite($f, "connection busy\n");
pg_cancel_query($connection);
fwrite($f, "query killed\n");
}
// close connection
pg_close($connection);
fwrite($f, "connection closed");
}
else {
fwrite($f, "not connected\n");
}
fclose($f);
}
?>
With this set up, the user enters test.php. Stops before the query
finishes. It should call leave(). However, this dose not happen. I
believe it is because the script has not finished and passed the page
text to the browser (pls correct me if I'm wrong), until php has
finished processing it.
I've tried using register_shutdown_function() as:
test.php
<html>
<body>
<?php include "functions.php";
global $connection;
$connection = pg_connect("host=localhost dbname=test user=test");
register_shutdown_function("close_con");
echo $connection." connection <br>";
echo pg_connection_status($connection)." status<br>";
pg_send_query($connection, "SELECT COUNT(id) FROM test");
echo pg_connection_busy($connection)." busy<br>";
$res = pg_get_result($connection);
echo pg_num_rows($res)." # rows<br>";
echo $GLOBALS["connection"]." GLOBALS<br>";
?>
</body></html>
The functions.php as above.
This also dose not work as, " The registered shutdown functions are
called after the request has been completed" (from
).
I'm interpreting that as, any functions in the list will not be
called until the pg_send_query() or the pg_get_result(), not sure
which, returns. Then close_con() from functions.php is called via
register_shutdown_function(). Thus I'm unable to cancel the query :(
Any comments, suggestions or work arounds would be greatly appreciated.
I'm using PHP 4.2.3
Cheers
Noel
//---------------------------------------------------------- -------------------
Muhyiddin A.M Hayat wrote:
cite="mid00aa01c3aec5$3fb5df60$2b179fca@middinkcomp">
color="#ff0000" size="1">
color="#ff0000" size="1"><body
onunload(<?close_connection($connection)?>)>
color="#ff0000" size="1">onunload
above can't call function from PHP, but it called from javascript, you
can create javascript function to call PHP function/file that you wanna
PHP do
size="1">
color="#ff0000" size="1">
size="1"><?php
//
close_connection.php
include(
face="Courier New" color="#ff0000" size="1">'connection.php'
face="Courier New" color="#000000" size="1">);
global
size="1">$connection
size="1">;
function close_connection(
color="#580000" size="1">$connection
color="#000000" size="1">){
//
close_connection here
// .....
face="Courier New" size="1">
// .....
face="Courier New" size="1">
// .....
}
close_connection(
size="1">$connection
size="1">);
echo
size="1">"<SCRIPT>window.close();</SCRIPT>"
face="Courier New" color="#000000" size="1">;
?>
color="#ff0000" size="1">
size="1">---------
color="#ff0000" size="1">
size="1"><html
face="Courier New" color="#0000ff" size="1">>
<
face="Courier New" color="#800000" size="1">SCRIPT
face="Courier New" color="#008080" size="1">
face="Courier New" color="#ff0000" size="1">LANGUAGE
face="Courier New" color="#0000ff" size="1">="JavaScript">
face="Courier New" size="1">
<!--
face="Courier New" color="#008080" size="1">
face="Courier New" color="#585858" size="1">Begin
face="Courier New" size="1">
function
face="Courier New" color="#008080" size="1">
face="Courier New" color="#585858" size="1">leave()
face="Courier New" color="#008080" size="1">
face="Courier New" color="#585858" size="1">{
face="Courier New" size="1">
window.open('close_connection.php','','toolbar=no,menubar=no ,location=no,height=10,width=10');
face="Courier New" size="1">
}
face="Courier New" size="1">
//
face="Courier New" color="#008080" size="1">
face="Courier New" color="#585858" size="1">End
face="Courier New" color="#008080" size="1">
face="Courier New" color="#585858" size="1">-->
face="Courier New" size="1">
</
face="Courier New" color="#800000" size="1">SCRIPT
face="Courier New" color="#0000ff" size="1">>
<
face="Courier New" color="#800000" size="1">body
face="Courier New" color="#008080" size="1">
face="Courier New" color="#ff0000" size="1">onunload
face="Courier New" color="#008080" size="1">
face="Courier New" color="#0000ff" size="1">=
face="Courier New" color="#008080" size="1">
face="Courier New" color="#0000ff" size="1">"leave()">
</
face="Courier New" color="#800000" size="1">body
face="Courier New" color="#0000ff" size="1">>
face="Courier New" size="1">
</
face="Courier New" color="#800000" size="1">html
face="Courier New" color="#0000ff" size="1">>
//----------------------------------------
ljb wrote:
wrote:
I have a small problem. Is it possible to cancel a running query when a
person leave or pressed the stop button in my web page.
....
Have tried
<?php
include "functions.php";
$connection = pg_connect(host, dbname, user);
?>
<html><body onunload(<?close_connection($connection)?>)>
> ...
>
> This will never work, as you found. The Javascript action is client-side
> and PHP is server-side.
>
> Try using register_shutdown_function() to register a function which will
> call pg_cancel_query(). As long as PHP isn't ignoring user aborts (see
> ignore_user_abort()), your query will be cancelled when the user hits STOP.
> Another way is to ignore user aborts, and while waiting for the
> asynchronous query to finish, keep calling connection_aborted() to see if
> you are still connected to the user; if not you cancel the query and exit.
--
Noel Faux
Department of Biochemistry and Molecular Biology
Monash University
Clayton 3168
Victoria
Australia
--Boundary_(ID_guCDxg5vhcnlCQv3p5oAOw)--