Page Refresh

**InNeedofHelp** · 06-24-2006, 08:10 PM

Is there anyway to refresh a page based on user input using php? or am i looking at javascript? Basically, i have a chatroom, and i don't want to use a meta tag because i want the page to refresh faster than every 5 or 1 seconds if it has to, or as slow as it has to, based on when any of the users sends a message. For example, 4 people are in my chatroom, one of them sends a message, and each of the 4 peoples page refreshes. Is that even possible using PHP or javascript?

Thanks.

P.S.: Sorry if this is in the wrong forum. I figured Javascript was strictly browser based and wouldn't be able to update each active user's page, and therefore i posted in here.

**djr33** · 06-24-2006, 08:15 PM

No. PHP is not realtime.
And, no. Javascript cannot access the server.

The ONLY way to do what you are asking is using AJAX.
More complex, but it's worth looking into.

**InNeedofHelp** · 06-24-2006, 08:20 PM

Oy, I was afraid of that. Hehe. I'm busy learning PHP, and all the while I'm learning more Javascript (it seems like to learn all of javascript would take an entire lifetime). I didn't want to have to get into AJAX too haha. Ah well, any idea where I can find a good AJAX tutorial to help me with this problem?

Thanks.

**djr33** · 06-24-2006, 08:25 PM

Not sure. I know WHAT AJAX can do, not so much HOW it does it

It is all javascript based, though.

You send a request for a page, using javascript. That is "AJAX".
Then you'd control that process using javascript, ifs, loops, user input, whatever.
Not TOO complex... but certainly advanced.

**Twey** · 06-24-2006, 08:57 PM

The server cannot initiate a connection to the client. The client must send a request before any data can be sent by the server. This means that you have no way of telling when there is a new message available. You simply have to refresh periodically. Through trial and error with people of different connection speeds, I find five seconds is probably the best interval.

**djr33** · 06-24-2006, 08:59 PM

The only catch is that using AJAX, you can "refresh" every 5 seconds, but only actually refresh the text if it varies from what it was before.
That's a very nice trick, and looks a lot better than flashing text.

But, exactly... the server can't initiate anything. That's the hard part about coding chatrooms, etc.

**InNeedofHelp** · 06-24-2006, 09:34 PM

Hm. So I'm probably better off just using a meta tag?

**Twey** · 06-24-2006, 11:28 PM

You're better off using XMLHttpRequest, then falling back on a meta tag. Check out the PHP/MySQL chat I wrote for Johnnymushio. I hope he won't mind my using it as an example, I've just moved to a new host and I don't have everything up yet.