POST variables not retained by Full URL INCLUDE statement

LukeDouglas

Why are POST variables not passed to INCLUDE sections when a full URL, such as "http://www.douglashosting.com/include-detail.php", is used instead of a relative URL, such as "include-detail.php"?

Here is the code:
Source File:
input.html
<form method="POST" action="detail.php">
<input type="hidden" name="RecordNumber" value="3">
<input type="submit" value="View All Images">
</form>

Results Main File:
detail.php
<?
$RecordID=$_POST['RecordNumber'];
echo "Main RecordID=" . $RecordID . "<br />";
?>
<?php include("include-detail.php"); ?>

include-detail.php file:
<?php
echo "Include RecordID=" . $RecordID . "<br />";
?>

Displayed Results:
Main RecordID=3
Include RecordID=3

Now here is the change in the detail.php page that fails.

Modified Results Main File:
detail.php
<?
$RecordID=$_POST['RecordNumber'];
echo "Main RecordID=" . $RecordID . "<br />";
?>
<?php include("http://www.douglashosting.com/include-detail.php"); ?>

Displayed Results:
Main RecordID=3
Include RecordID=

As you can see, when the full URL "http://www.douglashosting.com/include-detail.php" is used, the $RecordID variable is not retained.

I even tried re-initializing the variable in the include-detail.php page.

Modified include-detail.php file:

<?php
$RecordID=$_POST['RecordNumber'];
echo "Include RecordID=" . $RecordID . "<br />";
?>

Displayed Results:
Main RecordID=3
Include RecordID=

Again, the results are the same.

Can anyone explain why this happens?

Thanks.

drew010

by including a file using its server path (i.e. /home/username/www/somefile.php or ./folder/somepath.php) when include fetches the file, it reads the contents directly via the file system and includes the php code untouched.
if you use http in the include, its actually making an http request for that file, just like your webbrowser does, therefore, the page it brings via [url]http://[/url] is parsed php code already executed.

did that make sense?

LukeDouglas

Drew, thanks for the response.

Basically what your saying is that using a fully qualified URL is just the same as loading a completely different page even though it is included in the page, therefore, since no POST variables were sent to the include page, it doesn't recognize those variables.

If you only have the folder and pagename in the INCLUDE statement, then it brings that file into the page without loading the page as a separate HTTP request.

OK. That makes sense. Never really thought about it all these years. I only recently started developing pages with fully qualified URL's so I guess I better stop doing that with PHP pages.

Oh! Well. If you don't learn something everyday, even at my age, then your falling behind and I'm already so far behind, I can't see in front of me!!!

drew010

Yeah you pretty much got it now it sounds like.
As you well know, when you call http://www.yoursite.com/script.php, the request is patched to your webserver and then the subsequent php code is executed and returned to your webserver which then gives the output to you.

With a php include that has [url]http://[/url] in it, php really doesnt know if the file is local or remote so it makes an http request for the file, which in turn parses it and then gets the output. That output is then brought into the new script.

of course in a basic script like
<?php echo $var1; ?>
var1 doesnt actually exist in that script, so nothing would be output (this is what happens in your case).
if you have another script...
<?php
$var1 = "something";
include("./scriptabove.php");
?>
var1 is now defined, and the contents of the file (echo $var1) is just brought into the new file and $var1 is defined so it is able to echo.

So yeah, you are right, when you use the http include, none of the post vars were set because the script was referencing undefined variables.