Iframe PHP chat (refresh method help needed)

Evanatmtd

Ok, i have a php chat i am coding 100% from scratch, i am ALMOST done, but i need to get this one LAST code working... the chat window (were the messages are displayed) is an iframe above a text box and submit button... Following? OK, well I have it post new messages to an HTML file in this format:

 
<b><font color=red>$username: </b></font><font>$message</font><br>

I want the iframe to post the latest message, but i dont want to use the conventional meta refresh... so i came up with this...
The PHP will check the filesize of the messages.html file....
Then it will loop a command that compares the filesize to what the filesize was when it first checked.... If it notices a change in filesize (because a message was saved to the file), it will grab the last line of the HTML file, and put it to a variable, then print "$that_variable'; and then loop to the begining of the file and start all over.... therfore, as soon as a message is sent, it should post.

AstroTeg

Ack! on the goto statements 🙂

This:

echo '$message';

Isn't going to work as you're thinking it will.

Single quotes: No PHP processing of variables
Double quotes: PHP processing of variables
No quotes: Treated as a string.

Just do: echo $message;

Save some typing and stress on PHP.

You briefly talked about how you would identify when the file would get updated.

As you loop, if you keep constantly looping without letting the processor/hard drive take a break, you can really tie up the processor and tick off your web host. Not a good situation. Put a sleep() in there.
The file changes. You grab the last line. Is it possible multiple lines could have been inserted quickly enough that when you read the last line, you miss reading the last couple of lines? Something to ponder...
Instead of checking for file size, you can also check for file date. In this situation, either will work fine.

Evanatmtd

wow, thanks didnt think about missing a line that was inserted, and yeah i found out the processer gets screwed over when i ran a quick test... also is there such thing as goto command? lol i was just saying that as an example.... do you have AIM? really want to get this up and running, i have all the code done for the chat except this..... thanks

Weedpacket

Originally posted by Evanatmtd
also is there such thing as goto command?

No; nasty, hateful things - almost never justifiable. What you wrote looks like

while(true)
{ // Loop:
....
} // Goto Loop!

and you'll need to use a [man]break[/man] statement in there somewhere to jump to the point after the end of the loop or you'll be stuck in it forever.

Evanatmtd

yeah, i have been contemplating this outside the forum for a day now, and i was kindof thinking i do want a loop that goes forever as loong as it prints new messages.... Unless someone else knows a better way to refresh without the dreadful meta blink???? I tried using the fade page exit transition but it starts looking like crap once the messages exceed the height of the iframe... Any ideas?

Evanatmtd

Oh, also I run my own server so i can turn off the PHP timeout :-)

AstroTeg

I wouldn't do this. If you accidentally create an infinite loop when you didn't want to, PHP will not gracefully stop that loop. I'd leave the timeout in php.ini alone and just toss in a set_timeout() setting (set it to 0).

Evanatmtd

OK, I added the set_timeout(0); thanks for the tip...
Any other ideas guys? You are all doing great.