asked on

php problem?

I have a very simple php program (attached). It is linked to from another place.

In Firefox, I get the attached jpg.

In Chrome I get a blank screen.

I ran the php syntax through http://phpcodechecker.com/. No issues.

What's wrong?
clear_sess.php
php_issue.jpg

Ray Paseur

Please use the code snippet feature to post code samples here at E-E, thanks.

<?php
// clear_sess.php
function conv_date($x) {
		$d = explode("-", $x);
		$r = $d[1] . "/" . $d[2] . "/" . $d[0];
		return $r;
	}
include "db_connect.php";
session_start();
$qry = "SELECT * from users where uid = '" . $_SESSION['uid'] . "'";
$uid = $_SESSION['uid'];
$res = mysqli_query($link, $qry);
$nr = mysqli_num_rows($res);
$u = mysqli_fetch_array($res,MYSQLI_ASSOC);
session_unset();
$_SESSION['uid'] = $u['uid'];
//echo $u['firm_name'] . "<br>";
$_SESSION['firmname'] = $u['firm_name'];
$_SESSION['addr1'] = $u['addr1'];
$_SESSION['addr2'] = $u['addr2'];
$_SESSION['phone'] = $u['phone'];
$_SESSION['tester'] = $u['tester'];
$_SESSION['tg_make_model'] = $u['tg_make_model'];
$_SESSION['tg_sn'] = $u['tg_sn'];
$_SESSION['tg_date_cal'] = conv_date($u['tg_date_cal']);
$_SESSION['city_tester_no'] = $u['city_tester_no'];
if(! empty($_SERVER['HTTP_USER_AGENT'])){
		$useragent = $_SERVER['HTTP_USER_AGENT'];
		if( preg_match('@(iPad|iPod|iPhone|Android|BlackBerry|SymbianOS|SCH-M\d+|Opera Mini|Windows CE|Nokia|SonyEricsson|webOS|PalmOS)@', $useragent) ){
			$loc = "phone.php";
		}
	} else {
	$loc = "form.php";	
	}
header("Location: " . $loc);
exit;
?>

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Ray Paseur

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Richard Korts

ASKER

Ray,

I found the issue; the variable $loc was not set in the non iphone, etc. devices case. Therefore, the header("Location: " . $loc) could not work. Makes PERFECT sense that Chrome displays a blank page.

Because of your questions I put in a bunch of echos, they led me to the solution.

Richard

Ray Paseur

Great!

A "standard" design pattern in almost any programming language is to assign the default variable values before any conditional code block that can change the variable values. So something like this would be wise...

// SET DEFAULT VALUE TO REDIRECT TO THE HOME PAGE
$loc = '/';

// TEST USER AGENT FOR "PHONE" INDICATORS, CHOOSE REDIRECT PATH
$useragent = !empty($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : NULL;
if ( preg_match('@(iPad|iPod|iPhone|Android|BlackBerry|SymbianOS|SCH-M\d+|Opera Mini|Windows CE|Nokia|SonyEricsson|webOS|PalmOS)@', $useragent) ) {
    $loc = "phone.php";
} else {
    $loc = "form.php";  
}

// GOTO THE APPROPRIATE SCRIPT LOCATION
header("Location: " . $loc);

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Richard Korts

ASKER

That's EXACTLY what I did.

I often do that but not consistently.

R