[RESOLVED] Selective Content display or Banging my head against a wall

Crimsondrac

I am hoping there is some nice programmer who is willing to give me a hand. I am pretty new to PHP and barely know enough to be dangerous. All the tutorials I found on the net are pretty old and use the Register_Globals. I made a page using the old style code. However, recently, I had my Hosting company move my site from a server with PHP 4 on it to a server that has PHP 5. Now my code don;t work anymore.

I am basically trying to make a page that has the states listed in HTML. Each state has a hardcoded link to pass a variable for that state. When you click on the link for a state, only that state's info should be displayed. However, I am having a difficult time understanding how to make the Superglobals work.

This is the code as it was on the PHP 4 server with Register Globals on.

Any input would be soooooo appreciated.

<?php

$db = mysql_connect("localhost", "user", "pass");

mysql_select_db("database1",$db);

if ($state) {
   $result = mysql_query("SELECT * FROM table1 WHERE state='$state'",$db) or die ('Error: '.mysql_error ());

   $myrow = mysql_fetch_array($result);


   printf("<TABLE BORDER=1 CELLSPACING=2 CELLPADDING=2><TR ALIGN=CENTER><TD><FONT SIZE=+2 COLOR=#000088>PICTURES</FONT></TD><TD><FONT SIZE=+2 COLOR=#000088>DOWNLOAD</FONT></TD><TD><FONT SIZE=+2 COLOR=#000088>REQUIREMENTS</FONT></TD></TR>");

   printf("<TR ALIGN=CENTER><TD>%s</TD><TD><a href=%s/%s>%s</a><BR><a href=%s/%s>%s</a></TD><TD>%s</TD></TR>", $myrow["desc"], $_SERVER['PHP_SELF'], $myrow["p01"], $myrow["p01d"], $_SERVER['PHP_SELF'], $myrow["p02"], $myrow["p02d"], $myrow["req"]);

   printf("</TABLE>");


} else {

printf("<FONT SIZE=+3 COLOR=#FF0000 FACE=Tahoma><HR WIDTH=300><B>Please make a selection<B><BR><HR WIDTH=300></FONT>");
}

?>

etully

As a quick hack, just to get your site working again, you can simulate the behavior of Register Globals by adding this code to the top of your pages:

<?php foreach ($_REQUEST as $k => $v) { $$k = $v; } ?>

However, this trick should be used by people who know what they are doing. There's a reason that Register Globals was turned off. If you don't understand why it was turned off, then it would be dangerous to make the decision to effectively turn it back on without knowing the risks. You can use this trick to get back on your feet... but you since you described yourself as "barely know enough to be dangerous", at a minimum, you should learn the correct way to program in an environment that doesn't have RG's. Ideally, you should learn why RG's are dangerous in the first place.

Basically, the correct way to program in an environment without RG's boils down to this:

If you have an <input> tag in your form that's named "city" and you want a varaible called $city in your PHP page, then you should put this at the top of your code:

$city = $_REQUEST['city'];

That's it. It's as simple as that. Much safer than relying on Register Globals.

laserlight

It's as simple as that.

Almost, but not quite. $REQUEST['city'] is an incoming variables, and such variables must be checked for existence with [man]isset[/man] or [man]empty[/man] before use. So you might modify etully's example to be:

$city = isset($_REQUEST['city']) ? $_REQUEST['city'] : '';

Or perhaps you could use some default value instead of a blank, or even reject the form submission and request that the city field be filled out.

Crimsondrac

Thanks for the help. I tried etully's example first and it took me a minute to figure out where to put it, but it worked but generated an error until it was fed a variable. Then I replaced it with laserlight's and the error went away. Thank you so much. I had no idea one line would fix it.

I do understand why Reg Globs should be turned off. and I understand the concept of the superglobals. However, there do not seem to be many updated tutorials out there that show you how to do stuff with reg globals off.

I do appreciate your help and you will probably see me on here again. 🙂