Saw this but can't get it to work

[Bizzle]

I have seen a few pages where the links are something like ?pg=contact instead of contact.php

I came across a tut in the book I am reading that kind of made use of this but it turns out that the tut code didn't even work. I have been playing with this for some time but I just don't get how this works. So far what I am to understand is that what comes after the ? is a variable and what is after the = is what page it is assigned to.

I could be far off with this but could someone please tell me how this works and maybe give an example? Thanks.

[LordShryku]

They are get variables. ? defines the start of the query string, & seperates variables in the string.

/*
 * Assume this is 
 *    page.php?var=1&blah=2&baz=3
 * Use isset to make sure they are set, then echo them.
 */

if(isset($_GET['var'])) {
   echo "Var = ".$_GET['var']."<br />";
}

if(isset($_GET['blah'])) {
   echo "Blah = ".$_GET['blah']."<br />";
}

if(isset($_GET['baz'])) {
   echo "Baz = ".$_GET['baz']."<br />";
}

[Bizzle]

I'm still a little confused as to how this comes back to doing links and accessing pages. Forgive me I'm very new to PHP. If I want to break my site up into categories i.e. essays, movies, etc and each essay or movie is it's own page how would I do that. I know it's supposed to look like ?essay=essay1, ?essay=essay2, or ?mov=movie1 but I don't see how this code does this.

[rachel2004]

Out of curiousity, what book are you studying out of and what page are you looking at?

[Bizzle]

A Programmer's Introduction to PHP 4.0 By W.J. Gilmore

I kinda get the feeling that this book is a little old because 90% of the examples I have followed have needed some toying with to get to work.

[Mordecai]

Yep. It's a bit too old for this sort of thing (in PHP 4.1, the default value for register_globals changed to off, which means you can't use $variable in place of $_GET['variable']).

Keeping in mind Shryku's code to check whether or not the variables are set (instead of the echoes, use this):

  include $_GET['var'].".php";

If you go to page.php?var=1, it will include 1.php. If you go to page.php?var=contact, it will go to contact.php.

[rachel2004]

Originally posted by Bizzle
A Programmer's Introduction to PHP 4.0

I've gone through a number of PHP books, so I thought maybe I might have something that you were using, but I don't have that one.

O'Reilly is what I reference pretty often, but for a pretty good "tutorial" book:

http://www.amazon.com/exec/obidos/tg/detail/-/067232525X/ref=pd_bxgy_text_1/104-5220189-9075163?v=glance&s=books&st=*

[drew010]

also keep in mind that search engines such as google and yahoo dont index pages with variables in the query string. so unless you dont want or dont care about your site being indexed, this method is not recommended.
if you do want to simplify things for yourself, you can use mod_rewrite to make search engine friendly pages but they are really references to a single page.

i.e. for a client the website is programmed so their website is accessable like index.php?s=page but i use mod_rewrite to rewrite all urls like pg-SOMETHING.php to point to /?s=SOMETHING

[Bizzle]

Thanks for all the help everyone, I'm going to play around with this and see if I can get it to work.

I will def. start using a new book as I'm guessing some of the things I have learned already are no longer correct. I have the Sams Teach Yourself MySQL, PHP, and Apache in 24 hours but I found myself wanting to know more PHP so I would understand everything else better.

It's not even so much as I want to use this in my web projects, I just wanted to know what it was and how to use it in case I wanted to. I run a few web sites and thought this might be an effective way to access pictures and essays from a database. It is very helpful to know that doing it this way doesn't get it indexed in search engines..that will come in handy in the future.

Once again, thank you everyone for the help.

[Bizzle]

I've played around with this and it's still not making sense to me. I hate to ask but is there any way someone can make a quick working example and show me the code? I know if I see how it works I will be fine with it.

[drew010]

for the site i mentioned, this is the exact code used:

index.php

<?php

$docroot = "/home/sig/www/";

switch($_GET['s']):
	case "about": 		include($docroot . "about.php"); 	break;
	case "featured": 	include($docroot . "featured.php"); break;
	case "gallery":  	header("Location: /gallery/index.php");  break;
	case "clients": 	include($docroot . "clients.php"); 	break;
	case "contact": 	include($docroot . "contact.php"); 	break;
	default: 			include($docroot . "main.php");
endswitch;

?>

so it works like index.php?s=featured
checks what page they request, if it is in the list, it includes the page. for security you should always have at least some part of your filename or path being in the include, because if you just do something like include($_GET['s']), they can specify a remote url and execute php code on your site.

[Bizzle]

Thank you very much. One thing though, the index.php?s=featured etc works but the index.php itself does not work. It says

Notice: Undefined index: s

I'm going to keep plugging away at this whole thing but does anyone know what that means?

[Bizzle]

Also, no matter what I do, the default in the switch statement always comes up and when I added links on the index.php page those links remained on the page even when I went to those links. I know this is because of the use of include but this seems like it still needs some toying with before it can be used in the basic page format I am looking for.

[drew010]

to get rid of the undefined index, you can do
switch(@$_GET['s'])

[Bizzle]

Thank you very much.