Dynamically updating URL's within PHP code

[PEBAL]

Hi there.

I am hoping someone can help me figure out how to dynamically update a url string within some php code I use.

Situation:
I have the following url format: http://www.mysite.com/folder/page.php?sub=1234

The subid variable (1234 in the above instance) changes dynamically based on various criteria of the referring site.

Problem:
I have some php code on my page that does allows me to treat visitors differently depending on where they come from, but regardless, I need to pass this variable (1234) by appending it to the next page url.

Here's a snippet of my code:
<?php

$seedvar=$_GET[sub];

$new_page_url = 'http://www.new-page.com?sub=<?php echo $seedvar; ?>';

What's happening however is that instead of appending the variable 1234 to the new page url, the code is just sending the url as is - so... http://www.new-page.com?sub=<?php echo $seedvar; ?> instead of http://www.new-page.com?sub=1234

It seems to me that the my intention of having the variable updated automatically is not executing for some reason and I'm assuming it's because I've not coded it correctly.

I'm hoping this is an easy fix and that someone would be able to hep me out.

Thanks in advance for any suggestions.

Cheers,

Peter

[mrbaseball34]

Try this...

$new_page_url = 'http://www.new-page.com?sub=$seedvar';

[bradgrafelman]

Note that in the above code snippet, the 'sub' entity in the query string will be populated with a dollar sign followed by 'seedvar'. Since you want variable interpolation to happen, you'd have to use double quotes as the string delimiter instead of single quotes.

Also note that the error in your original code is that you're trying to add PHP code (tags and all) inside of a string. The only thing strings might be parsed for (depending upon how you're defining the string in question) are either variables or special escape sequences (e.g. "\n" for a line feed character).

See the manual page on what a [man]string[/man] is for more information.

[PEBAL]

mrbaseball34;10958820 wrote:

Try this...

$new_page_url = 'http://www.new-page.com?sub=$seedvar';

Thanks for the suggestion mrbaseball34, but unfortunately it didn't work. What got passed onto the next page was: http://www.new-page.com?sub=$seedvar ...instead of it automatically populating it with the variable to look like: http://www.new-page.com?sub=1234

For some reason I can't get the action to take place within the php code within the url string.

I think that the reply from bradgrafelman might hold the answer, but unfortunately, after reading it and reviewing the provided resources... I still can't figure it out.

If someone has nay better ideas... I'd love to hear them!

Thanks again for any and all help.

Cheers,

Peter

[bradgrafelman]

Err... I didn't really leave much to "figure out" ... I gave you the answer:

bradgrafelman;10958824 wrote:

you'd have to use double quotes as the string delimiter instead of single quotes.

EDIT: More food for thought... when populating a query string with variable data, you should consider whether or not that data can contain special characters that might break the URL/query string and, if so, encode the data instead (see [man]urlencode/man, for example).

[PEBAL]

Brad,

Here's what I read your post to mean, instead of...
$new_page_url = 'http://www.new-page.com?sub=$seedvar';

use double quotes; so...
$new_page_url = "http://www.new-page.com?sub=$seedvar";

Now, that may not be what you meant, but that's how I read it and unfortunately that didn't work.

Interestingly enough it totally blanked the variable so that the result is that it forwarded to the following page (and dropped the variable)...
http://www.new-page.com?sub=

Let me know if I misunderstood your direction and if not, if you have any other suggestions I could try.

Thanks!

Peter

[bradgrafelman]

If nothing was added in its place, then apparently the variable $seedvar is empty or undefined.

[PEBAL]

I thought that might be the case also so I ran a test using Live HTTP headers to ensure that the referrer is sending the ?sub=1234 string and it is.

So even though the sub= variable is in the header url for the taking, per your note, it appears that the code $seedvar=$_GET[sub]; is not picking it up???

Any idea why &/of how I can improve that?

Thanks

Peter

[bradgrafelman]

What do you mean by referrer/header? $_GET is populated with data from the query string in the URL of the present request... if you want to retrieve data from the Referer HTTP header, then that's something entirely different.

[PEBAL]

If i send traffic to this landing page from Google, then I might make the url string look like:

http://www.new-page.com?sub=5647 this number (5647 in this case) identifies specific characteristics about my traffic source that I need to have passed on to the next page.

So when the traffic arrives at my page the header url is pre-populated with the sub=5647 variable.

I was using the code $seedvar=$_GET[sub]; to grab the 5647 variable with the intent to populate it into the url we've been working on and which is the webpage that the visitor goes to next.

Sorry if I didn't explain myself adequately the first time around.

Cheers.

Peter

[bradgrafelman]

Do a [man]print_r/man on the $_GET array to see what data it has. If the "sub=5647" is in the query string of the page where you're using the above code, then it should work. If it doesn't, show us what the print_r() statement outputs.

[PEBAL]

Brad... it did indeed print the correct variable when I tested with the Print_r()... so I assume that capturing the sub is not the problem.

When I reviewed my Live HTTP headers log it appears that the PHP code within which this is embedded (and which does the sorting and sifting) is doing some other things to mess this up.

It appears that before it forwards to this url we've been working on, it is refreshing the page on itself, but dropping the sub=???? variable in the process and that's why it's not populating.

Here is the entire code. Perhaps you can figure out how I can tweak it to keep the sub= variable even after the refresh???

<?php

$magic_number = 1234

$seedvar=$_GET[sub];

$new_page_url = "http://www.new-page.com?sub=$seedvar";

if (isset($GET['mn']) && $GET['mn']==$magic_number){

	echo '<html><head></head><body><form action="' . 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'] . '" method="post" id="form1">

<input type="hidden" name="mn" value="' . $magic_number . '" /></form>

<script language="JavaScript">
document.getElementById(\'form1\').submit();</script></body></html>';
return true;
exit();
}

if ($_POST['mn']==$magic_number){

echo '<html><head></head><body><form action="' . 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'] . '" method="post" id="form1">

<input type="hidden" name="mn" value="' . $magic_number . $magic_number . '" /></form>

<script language="JavaScript">
document.getElementById(\'form1\').submit();</script></body></html>';
return true;
exit();
}

$dom = preg_replace( "/^www./", "", $SERVER[ 'HTTP_HOST' ] ) ;
$ref= $SERVER['HTTP_REFERER'];

if (((strpos($ref, $dom)!=FALSE) || (trim($ref)=="" ) ) && ($_POST['mn']==$magic_number.$magic_number)){
header( 'Location: ' . $cpa_offer_url);
exit();
}

?>

---

Thanks again for all your help!

Peter

[PEBAL]

Ooops... there was a small error in what I posted previously, It's fixed here.

---

Brad... it did indeed print the correct variable when I tested with the Print_r()... so I assume that capturing the sub is not the problem.

When I reviewed my Live HTTP headers log it appears that the PHP code within which this is embedded (and which does the sorting and sifting) is doing some other things to mess this up.

It appears that before it forwards to this url we've been working on, it is refreshing the page on itself, but dropping the sub=???? variable in the process and that's why it's not populating.

Here is the entire code. Perhaps you can figure out how I can tweak it to keep the sub= variable even after the refresh???

<?php

$magic_number = 1234

$seedvar=$_GET[sub];

$cpa_offer_url = "http://www.new-page.com?sub=$seedvar";

if (isset($GET['mn']) && $GET['mn']==$magic_number){

echo '<html><head></head><body><form action="' . 'http://'.$SERVER['HTTP_HOST'].$SERVER['PHP_SELF'] . '" method="post" id="form1">

<input type="hidden" name="mn" value="' . $magic_number . '" /></form>

<script language="JavaScript">
document.getElementById(\'form1\').submit();</script></body></html>';
return true;
exit();
}

if ($_POST['mn']==$magic_number){

echo '<html><head></head><body><form action="' . 'http://'.$SERVER['HTTP_HOST'].$SERVER['PHP_SELF'] . '" method="post" id="form1">

<input type="hidden" name="mn" value="' . $magic_number . $magic_number . '" /></form>

<script language="JavaScript">
document.getElementById(\'form1\').submit();</script></body></html>';
return true;
exit();
}

$dom = preg_replace( "/^www./", "", $SERVER[ 'HTTP_HOST' ] ) ;
$ref= $SERVER['HTTP_REFERER'];

if (((strpos($ref, $dom)!=FALSE) || (trim($ref)=="" ) ) && ($_POST['mn']==$magic_number.$magic_number)){
header( 'Location: ' . $cpa_offer_url);
exit();
}

?>

---

Thanks again for all your help!

Peter

[PEBAL]

This matter has been addressed. Thanks for your help.