Delaying execution...

Sharif

I'm looking for a function that will help me do something like this:

Display the html result of: <p>ABCD</p>
Wait 3 seconds
Display the html result of: <p>EFGH</p>

Meaning as soon as the page loads you will see:

ABCD

After 3 seconds, you will see

ABCD

EFGH

flatpooks

surely an http redirect with a 3sec timeout would work?

Sharif

No I can't redirect, it would mess up the script.

flatpooks

sleep(3)

😉

Sharif

I tried that but that doesn't execute ANYTHING for 3 seconds.

flatpooks

so what exactly do u want it to do then?
u said "print "xyz" then wait 3 secs then print "abc"

so:

echo "xyz";
sleep(3);
echo "abc";

will do exactly what u asked for
?

Sharif

I tried that but it ends up echoing everything TOGETHER after 3 seconds, even if the sleep() is called in between.

flatpooks

are u trying to write out text bit at a time like in the movie special effects thing?

if so u gonna have to use a session var or something that holds the string as it is currently ... then u do something like this:

<?php
session_start();
// figure out what extra text u want to add to the string

$_SESSION['mystring'] .= $new_text_to_add;

echo $SESSION['mystring'];
sleep(3);
header("location:" . $SERVER['PHP_SELF'];
}

ozzythaman

what you want to do is flush the output buffer, look up the function in the manual, dont remember exactly, this is web server dependent, does not work with all web servers.

ksandom

I suspect I might be saying the same thing as "ozzythaman".

Look at the date function. The time function may also be worth a look.

Which every you use you would need to do the following in your script:

0) Do stuff before loop
1) Get time before operations
2) Begin loop
2.1) Do stuff in loop (stuff that you wanted it to do while waiting)
2.2) Compare current time to time before loop, exit when difference is greater than the time you wanted it to wait for.
3) Do stuff after loop.

You might also want to have a look at set_time_limit

mberman

try flush() (I think this is what ozzythaman was getting at), like:

<?PHP
     echo "ABCD";       //print "ABCD"
     flush();                 //clear the buffer
     sleep(3);              //sleep 3, and...
     echo "EFGH";       //print "EFGH"
?>

What's happening is that it's "echo-ing" to the buffer, waiting 3 seconds, adding to the buffer, and then printing the buffer. flush() is supposed to make PHP flush the buffer, in this case, before it waits 3 seconds.

As ozzythaman said, it doesn't work on some servers (including mine sniff ).

ksandom

wow, a lot happened between when I originally read the post and when I posted my original reply.

I've had this problem before. I only got it on Internet Explorer. Is this what you are using? If so, give another broswer a go.

The reason this happens is so that the browser doesn't continually redraw the screen each time another packet comes in. This way the page only gets redrawn a few times during the load and resources such as the processor aren't wasted too much.

Opera has an option for this where you can set how often it redraws the screen during the load. By default it is set to one second. (Preferences, Windows, Loading). There may be an equivilent option under internet explorer. I haven't looked.