If no header, use URL

jeffshead

I have a few error pages that users are automatically redirected to when a specific error message needs to be shown to the user. Each error page does an auto redirect back to the previous page after a few seconds and each error page also contains a link the user can click on if the auto redirect does not work.

I'm using $SERVER['HTTP_REFERER'] to get the headers for the redirect from the error page back to the previous page. The problem I have is sometimes there is no referer header so the redirect and link from the error page fail. Sometime I even get a PHP "Cannot modify header information - headers already sent by (output started at..." error which I guess is caused by one of the PHP script includes already using $SERVER['HTTP_REFERER'] .

Below is the code I have at the top of each error page for the auto redirect:

<?php
	if(isset($_SERVER['HTTP_REFERER'])){
	$ref = $_SERVER['HTTP_REFERER'];
	header( 'refresh: 4; url='.$ref);
  }  

?>

Below is the code I use for my links:

<a style="color:#0000FF;" href="<?php if(isset($_SERVER['HTTP_REFERER'])){	echo $_SERVER['HTTP_REFERER'];} ?>">Click if your browser does not redirect in 4 seconds.</a>

Below is a mock up of what I think will work, but I can't get the code right:

get  $_SERVER['HTTP_REFERER'] info
if $_SERVER['HTTP_REFERER'] empty, then use http://www.mysite.com
send referer if not already sent by other script

Can someone help me figure out the coding🙂

jeffshead

I already searched the file and found no white space before or after the PHP open and close tags.

jeffshead

Does this look correct?

<?php
	if(isset($_SERVER['HTTP_REFERER'])){
	$ref = $_SERVER['HTTP_REFERER'];
	} else {
	$ref = 'http://www.mysite.com';	
	header( 'refresh: 4; url='.$ref);
  	}  

?>

This works if the user's browser does not send the referer header but it does not work if the user's browser does send the referer header.

I moved the last curly bracket and it now seems to work.

<?php
	if(isset($_SERVER['HTTP_REFERER'])){
	$ref = $_SERVER['HTTP_REFERER'];
	} else {
	$ref = 'http://www.mysite.com';
	}
	header( 'refresh: 4; url='.$ref);
?>

Does this look OK? Is there a better way of doing this?

jeffshead

These error pages are part of a package that I want to be able to use on any domain so I do not want to add static URL's.

I ended up with the following code for the tops of the error pages...

<?php
	if(isset($_SERVER['HTTP_REFERER'])){
	$ref = $_SERVER['HTTP_REFERER'];
	} else {
	$ref = "http://" .$_SERVER["SERVER_NAME"]."/";
	}
	header( 'refresh: 4; url='.$ref);
?>

... and the code below for the link that's on those pages:

href="<?php if(isset($_SERVER['HTTP_REFERER'])){ echo $_SERVER['HTTP_REFERER']; } else { echo $ref; } ?>">Please click here if your browser does not redirect in 4 seconds.</a>

Both the refresh and the link seem to work OK with all of the error pages when using IE8, FF3.6.3 and Opera10.53 but not with Safari4.0.4.

One of my site's pages does a check for a hash and time stamp. If there is no match, then the user gets one of my error pages insted of the secured page. No problem with any browser except Safari.

With Safari, the error page just keeps trying to redirect to the secured page which just creates a loop and the URL specified for the link is that of the secured page. When testing with the other browsers, I am redirected to the sites home page and the link's URL is that of the home page ($ref).

Any ideas?