Global Variables

edzeak

I am passing a variable from one page to another from a drop down list. The variable passes fine to the second page, but after processing the second page I have it auto-refreshing to update any database activity that has occurred during the last 30 seconds. When I refresh I lose the value of the variable. I've tried the global Reference from the manual (page 183) with no luck. Here is the code snippet:

<td>
<?php
$db = mysql_select_db("regular_dispatch", $connection) or die ("Couldn't select database.");

			$result = mysql_query("SELECT max(id) as maxid, userid, name, active from drvmgr group by name",$connection);

			echo "<select name=drdm>";

			if ($myrow = mysql_fetch_array($result)) {

			do {	

			echo "<option name=drdm value=$myrow[userid]>$myrow[userid]:&nbsp;&nbsp;$myrow[name]</option>";

			}	

			while ($myrow = mysql_fetch_array($result));

			echo "</select>";

			}
			$drdm =& GLOBALS["drdm"];
			?>  
	</td>

In essence, what is the best way to declare a variable?

Or would isset a better example?

Thanks for all of your help.

rrijnders

<Snip!>
I am passing a variable from one page to another from a drop down list.
[How? Do you mean when the submit is pressed?]

The variable passes fine to the second page, but after processing the second page I have it auto-refreshing [you have what autrefreshing? The original form or the processing script?]to update any database activity that has occurred during the last 30 seconds. [Are you really updating a database, or updating the page with database activity?] When I refresh [Are you refreshing, or are you talking about that auto-refresh thing?] I lose the value of the variable. [define "loose". It doesn't show up, dissapears from the db, or maybe just no longer is the selected value of the drop down?] I've tried the global Reference from the manual (page 183) with no luck.[What makes you think this is a variable scope problem? I'm not trying to be snotty, it may give us some clues.] Here is the code snippet: [which page is this, the first or second?]
</Snip!>

edzeak

Wow, so many questions.
1. Page 1, there is a drop down list, the user selects the drop down list and clicks on Submit to use the value of the drop down list for the form processing on page 2.

2.Autorefreshing (ie. Meta "refresh"), the second page every 30 seconds, this way any db activity is reported automatically. Page 2 autorefreshes.

I am updating both, the db and the form. The user has inputs from a 3rd page into the db and the 2nd page automatically updates (this is the goal.) Currently, the user must click Reload or Refresh to see any further activity.

4.When I say lose, I mean the value from page 1 doesn't remain on page 2 when the Meta Refresh takes effect. and the value is essential to retrieving the data correctly.

I think it is a variable scope problem because, variables such as $PHP_AUTH_USER is global and remains throughout my sight, but I am not able to keep this variable value.
the code snippet is from page 1, where the drop-down list is located.

Thanks for any help.

rrijnders

ahhh, ok.

So the first page is the form with the drop-down box. The user selects a value and you POST to the second page.

The second page uses the POSTed variable to retrieve values from a db and display on the screen. It (the second page) also has a <META http-equiv="refresh" content="2; URL=http://www.mySite.com/page2.php"> in it to refresh the page and thereby updating the listed data with whatever has been recently added to the db.

ok.

First off, this is not a GLOBAL variable issue. GLOBAL scope refers to the context of the variable within a single script execution. When the second page refreshes, it is a new page execution and all variables from the previous execution (ie: the form POST) are gone.

What you want is actually data persistence. This means keeping data around from one script execution to the next. The standard way of doing this is to store the variable into a cookie or simply as as session variable the first time page2.php loads. Then on each refresh, read the value from the cookie or from the session variable.

In your case, you could achieve the same thing just by building the variable from the first POST right into the meta-refresh tag. If the variable from the drop down was id, then output the refresh tag like so:

print "<META http-equiv=\"refresh\" content=\"10; URL=http://www.mySite.com/page2.php?id=$id\">

This way, when the page refreshes, the variable will be there again. The only caviat is that if you have to reference the variable from HTTP_POST_VARS[] the first time and from HTTP_GET_VARS[] for the refreshed pages.

HTH
-- Rich

edzeak

WOW. That's great. Thank you for your help. This site is outstanding with most everyone helping each other. Thanks again.