Problem passing $_SESSION values to object methods

djheru

Hi All,

I have been creating a flash GUI image upload application. Within the method to resize and move the uploaded file, I am using the $SESSION['user_id'] to assign a value to the object property $userId to determine the path for the uploaded file to be moved to. For example:

class UploadClass
{
     var $_userId = 0;

function processUpload($userid)
{
     $this->_userId = $userid;
     $imgPath = '/uploads/images/galleries/g_'.$this->_userId;
     $thumbPath = $imgPath.'/t';
     if(isset($_POST['submit_upload']))
     {
          $resized = $this->resizeAndMoveImg($imgPath, $thumbPath, 300, 400, 90, 120);
          if($resized)
         {
               //Insert file info into db
          }
     }
}

//Calling the method
$upload = new UploadClass();

//This works just fine
$resizeAndMove = $upload->processUpload(1);

//this doesn't work at all, stores 0 in the database for the user_id value
$userid = $_SESSION['user_id'];
$resizeAndMove = $upload->processUpload($userid);

echo $userid; //Displays the number correctly, so it is being saved to $_SESSION array at login

That is the simplified version, of course, but the problem is that the value stored in $_SESSION['userid'] is not making it in to the method.

I've tried using

$userid = (int) $_SESSION['user_id'];

as well as

$userid = $_SESSION['user_id'];  $userid = (int) $userid;

all to no avail. Please help!

laserlight

Perhaps you forgot the session_start()?

djheru

Thanks for your reply. I have a file functions.php which calls require() on all of the different class files. This file calls the session_start(), and is included on all of the php files.

If I just echo $_SESSION['user_id'], it displays the data properly, but when I try to pass it to a method, the it seems to evaluate to zero.

laserlight

From what I see, the error must lie elsewhere. For example, attempt to print $this->_userId in processUpload() to check.

NogDog

This worked as expected for me:

<?php
class UploadClass
{
   var $_userId = 0;

   function processUpload($userid)
   {
      $this->_userId = $userid;
      $imgPath = '/uploads/images/galleries/g_' . $this->_userId;
      $thumbPath = $imgPath . '/t';
      if(isset($_POST['submit_upload']))
      {
         $resized = $this->resizeAndMoveImg($imgPath, $thumbPath, 300, 400, 90, 120);
         if($resized)
         {
            //Insert file info into db
         }
      }
   }
}
session_start();
$_SESSION['user_id'] = 123;

//Calling the method
$upload = new UploadClass();

//This works just fine
$resizeAndMove = $upload->processUpload(1);
echo $upload->_userId . "<br />";

//this doesn't work at all, stores 0 in the database for the user_id value
$userid = $_SESSION['user_id'];
$resizeAndMove = $upload->processUpload($userid);
echo $upload->_userId . "<br />";

Output was:
[indent]1
123[/indent]

djheru

Thanks for taking a look at it. The problem I'm having is bizarre, because when I call the function with a static value, i.e.

$resizeAndMove = $upload->processUpload(1);

, it works just fine. The images are resized and moved to the /g_1 directory. but if I do this:

$_SESSION['user_id'] = 1;
$userId = $_SESSION['user_id']; 
$upload->processUpload($userId);

It uploads the file to the /g_0 directory and stores 0 in the database as the user_id.

I've been pulling my hair out looking at this, but the only thing I can think of is some type of variable typing problem...

Even if I do this, it still doesn't work:

$userId = (int) $_SESSION['user_id']; //Maybe it is evaluating as Bool?
$userId = ($userId * 1); //Make sure it is looking at $userId as a number
$upload->processUpload($userId); //still evaluates "/uploads/galleries/g_".$userId as /uploads/galleries/g_0

Thanks again for taking the time to help with this. If you're willing, I could upload the entire class for you to review.

halojoy

take a look at
how class function processUpload( $arg )
handles the submitted variable.

Also make sure you use correct variable names.
Sometimes can be hard to see where is an UPPER Case char
where should be a lower case letter.

As you know, $userid is not the same variable as $userId. For example.
This is how PHP works.

You could put in some echo/dump of variable values at those critical lines.
I use var_dump() often for DEBUGGING.
http://docs.php.net/var_dump

regars, halojoy

halojoy

laserlight wrote:
Perhaps you forgot the session_start()?

I think also this may be.
Try to put a session_start() at top of that page
and see what happens ....

djheru

Thank you for taking the time to look at my question. I decided to look at the flash part of it, and I think that's what is causing the problem. The reason I didn't think it was the PHP code was because of the following:

$user_id = $_SESSION['user_id'];
echo $user_id; //displays 1 for example
$upload->processUpload($user_id);//This doesn't work

//Versus:
$upload->processUpload(1); //Works just fine

//or even
$user_id = 1;
$upload->processUpload($user_id);//Also works

Now, the flash file calls the php script asynchronously to handle the upload, and I think that must be the problem. I can't put a bunch of print_r's and echo statements in the method to trace what is happening because nothing gets displayed to the screen after the post occurs, it only shows when the .swf first loads.

So I changed a couple of the methods, and now the user ID value is passed to the .swf when it first loads, and the actionscript holds that value in one of it's class properties. Then, when the upload button is pressed, it sends the value back to the php script as part of the $_POST variables array.

Thanks again to all of you for taking the time to help.