referrer link

detect a particular referrer and provide link back to that referrer

[nunzia]

I need to detect the referrer for certain pages, and if it's a particular referrer, provide a link back to that referrer. If it's any other referrer, it should do nothing. I was working with this code

$ref = $_SERVER['HTTP_REFERER'];

if ( $ref = 'http://referring.page' ) {
echo ( "Return to <a href="http://referring.page/">Referring Page</a>") ;

} else {
} 

but not getting very far ... never tried something quite like this before. And could this be done as a function?

[TheMadScientist]

if ( $ref = 'http://referring.page' ) {
echo ( "Return to <a href="http://referring.page/">Referring Page</a>") ;

} else {
}

The single = in the if, which will evaluate to 'true' seems to be the biggest issue I'm seeing quickly, the best way to avoid this issue is to write your if statement the other direction.

$ref = 'http://referring.page' = true in an if
'http://referring.page' = $ref = false

Either way, it won't work, unless you use == or ===.

if($ref == 'http://referring.page') { }
if($ref === 'http://referring.page') { }

BTW: Welcome to WebmasterWorld!

[dreamcatcher]

Also, the referer is not available by default. You should check its existence before you use it:

$ref = (isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '');

dc

[nunzia]

thanks guys ... glad to have found you ... will let you know my progress

[nunzia]

ok, it's not crashing the page, but it's not displaying the link either.

$ref = (isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : ''); 

if ( $ref == 'http://referring.page/' ) { 
echo ( 'Return to <a href="http://referring.page/">Referring Page</a>') ; }

else {
}

Any ideas?

[Matthew1980]

Hi there nunzia,

Well that means as the code is doing exactly as you are asking it to!

$ref = (isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '');

If the $_SERVER['HTTP_REFERER'] isn't set then you are assigning it blank (no value) so $ref will equal: $ref = ""; but if it is set you are assigning it to the var. I think as you need a default value there then you will see the link get populated or you can place some code in the else clause like this:-

else{
echo "No referer set, cannot display link back to wherever you came from :)";
}

Because at the moment you have nothing in the else clause to tell you that the referer isnt set!

Hope I have explained that Ok for you,

Cheers,
MRb

[nunzia]

Doh! Bingo -- that's the ticket. Many thanks.

[rocknbil]

Or . . . give them something useful . . .

$ref = (isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : 'link-to-your-thank-you-or-sitemap-page');

[Matthew1980]

Hey Rocknbil :),

Yup, I realised that after I posted - at least using that would keep the traffic on your website.

nunzia: Glad your sorted, but as Rocknbil suggests, use the else clause/false side of the ternary to your advantage.

Good luck with the rest of the project.

Cheers,
MRb

[nunzia]

Beautiful. Thanks for the suggestion!

[nunzia]

Yikes .. one more thing. The referral could come from anywhere on the website referring.page. It could be referring.page/about.php or something. Or it could be www.referring.page, etc. How do I do the variables?

[TheMadScientist]

Change the if part of your code to:

if ( strpos($ref,'example.com')!==FALSE ) {
/* Do Stuff */
}

Will 'Do Stuff' every time example.com sends you a visitor.
strpos() [us2.php.net]

[nunzia]

Thanks Mad Scientist. That did it. Appears to now be doing everything I want it to do.