Php: Redirecting In Php

[authorblues]

you might want to note that the header function does NOT halt script execution. if you want to stop anything from happening (such as formal redirection), you need to call the exit or die functions right after header('Location:');.

in other words, if you call the header function to redirect, and then afterwards you have a piece of script that modifies a file or database, the header redirect will NOT stop the modification from taking place.

i always include a special function in my layout class to handle redirections. something like:

function formalRedirect($u){
header("Location: $u");
exit;
}

[WoogieNoogie]

Don't forget, you can't use the header function after any HTML. I had a bunch of problems with that when I was starting with it.

[DFox]

It seems like a good tutorial but PHP?>...? I've never heard of ending a PHP script like that.

[WoogieNoogie]

At 8/1/06 06:15 PM, Plakat wrote: Of course not. It should be the first thing. IMO.

Usually, when I redirect, that is the only thing the page is meant for, just so nothing gets weird. That's what I would suggest for anyone starting with header().

At 8/1/06 06:16 PM, GamesCool wrote: It seems like a good tutorial but PHP?>...? I've never heard of ending a PHP script like that.

Actually, me neither.

[authorblues]

At 8/1/06 06:19 PM, WoogieNoogie wrote:

At 8/1/06 06:15 PM, Plakat wrote: Of course not. It should be the first thing. IMO.

Usually, when I redirect, that is the only thing the page is meant for, just so nothing gets weird. That's what I would suggest for anyone starting with header().

why not just work with output buffering. then it doesnt matter when you send headers...

[DFox]

At 8/1/06 06:42 PM, authorblues wrote: why not just work with output buffering. then it doesnt matter when you send headers...

You could, but I find it cleanest to do all my PHP at the top of the page, so a redirect would never come into play after content was outputted. Then again that's just how I code.

[authorblues]

At 8/1/06 06:43 PM, GamesCool wrote: You could, but I find it cleanest to do all my PHP at the top of the page, so a redirect would never come into play after content was outputted. Then again that's just how I code.

i used to do the same thing, but its often awkward to workout where you put your headers. i find it easier to not worry about it by introducing output buffering. thats not to say that i dont stick all my php at the top, and attempt to get my headers sent first, but it just keeps me from doing some awkward workarounds.

[DFox]

At 8/1/06 06:47 PM, authorblues wrote: i used to do the same thing, but its often awkward to workout where you put your headers. i find it easier to not worry about it by introducing output buffering. thats not to say that i dont stick all my php at the top, and attempt to get my headers sent first, but it just keeps me from doing some awkward workarounds.

Yeah, I know what you mean, and that's definitley a good point.

Output buffering can definitley be useful at times.

[thecoshman]

if you want to use the header() to go to a page that is in teh same folder as the php script, can u just go

header('page.php')

[elbekko]

At 8/9/06 02:00 PM, thecoshman wrote: if you want to use the header() to go to a page that is in teh same folder as the php script, can u just go

header('page.php')

Yeah :)

[Craige]

At 8/1/06 05:45 PM, authorblues wrote: you might want to note that the header function does NOT halt script execution. if you want to stop anything from happening (such as formal redirection), you need to call the exit or die functions right after header('Location:');.

hmm, I never thought about that before. Makes sence though.

[Pilot-Doofy]

At 8/9/06 03:34 PM, Craige wrote:

At 8/1/06 05:45 PM, authorblues wrote: you might want to note that the header function does NOT halt script execution. if you want to stop anything from happening (such as formal redirection), you need to call the exit or die functions right after header('Location:');.

hmm, I never thought about that before. Makes sence though.

I believe that header() halts execution as long as you're not using an output buffer but I'm not sure.

[henke37]

Totaly wrong. Header is like any other function and normal functions doesn't terminate the script.

[Craige]

Yeah, the PHP.net site confirms that the function doesn't halt script exicution.

[DFox]

At 8/10/06 10:48 PM, Craige wrote: Yeah, the PHP.net site confirms that the function doesn't halt script exicution.

Yeah. It even shows exit; used after a header("location: tgr.com") call to stop the script.

[Craige]

At 8/10/06 10:51 PM, DFox2 wrote: Yeah. It even shows exit; used after a header("location: tgr.com") call to stop the script.

Yeah, I guess you learn something new every day.

[Rantzien]

Also, if you are working with sessions, the header function will not pass the session ID. This means session data will be lost unless you pass on the session ID manually, which must be done with the SID constant.

For example:
header ("Location: mypage.php?" . strip_tags (SID));

[Pilot-Doofy]

Why would you say you have to include a protocol (http, etc.) in the header call? That is simply untrue. I call header with relative linking all the time. In addition, like others said, you should encourage halting the script when a redirect is encountered.

Say, for instance, the script is on a page that would delete a private message from the database. Well, if they aren't logged in or it isn't their message to delete in the first place, steer them away from the page by using a redirect. However, if you don't halt the execution of the page, the message would still end up being deleted.

Even if they don't know if they succeeded, the damage is still done. I also don't think it would have been a bad idea to touch lightly on output buffers in this tutorial. If nothing else, give them a brief description and explanation and link to another tutorial (I'm sure there is one).

All in all, it wasn't too bad. But I think the main thing is to get totally know-it-all about the topic you're writing a tutorial on, otherwise the users aren't informed as well as they could be.