Storing Objects in a Session

[vadik_g]

Hi, guys I'm having this problem with storing Objects in the Session.

The Scenario is as follows:

What I do is I fetch a custom built RowSet [similar to ADO Recordset] with Data Items and want to store it in a dpCachedData class object with several additional variables.

1. I import dpCachedData class definition before I start the session [session.auto_start = 0 in the php.ini]

2. I instantiate the class with $Cache variable

3. I get the Rowset [which is alright]

4. I store the Rowset (and aditional vars) in the Session

5. While printing stored session class right after I put it there, I can see it is stored alright.

6. I go to other test page and printing the contents of my session object - the non object vars are alright, but the object is nothing ...

before i attach the samle code i just wanna say that i've been thru lots of posts on the subject and non seem to help, so please an anyone shed a light on this problem ...

The code:

[ dpCachedData.php ]

 
// ---------------------------------------------------------------------------------------
// class DPCachedData
//
// Doesn't have custom error handling.
// ---------------------------------------------------------------------------------------
class DPCachedData 
{
    var $m_rowSet; 				//_ DataItemSet object
    var $m_rootGUID; 			//_	DIS' root GUID if available
    var $m_currentPosition; 	//_ Last browsing of the set started here

// -------------------------------------------------------------------------------
// Constructor:
// + registers the destuctor function
// -------------------------------------------------------------------------------
function DPCachedData()
{
    register_shutdown_function(array(&$this, "Close"));

    return true;
} 
// -------------------------------------------------------------------------------
// Desctructor:
// + closes & the XML objects and all
// -------------------------------------------------------------------------------
function Close()
{
    if (isset($this->m_rowSet)) {unset($this->m_rowSet);} 

    if (isset($this->m_rootGUID)) {unset($this->m_rootGUID);} 

	if (isset($this->m_currentPosition)) {unset($this->m_currentPosition);} 

    return true;
} 
} //_ EOC: DPCachedData

···································································································

[ testSession_1.php ]

 
// _ requires DPCachedRowSet class definition
require_once("DPCachedData.php"); 

session_start();

$DPData; 		//_ DPDataFetcher class object
$XMLWrapper; 		//_ DPXMLDataWrapper class object

$parentID; 		//_ Data Item parent DBID
$startPos;		//_ Paging start position
$pageSize;		//_ Page length

$RURS; 			//_ DataItemSet reusable recordset

// _ requires DBDataFether class definition
require_once("DPDataFetcher.php"); 

// _ requires DPXMLDataWrapper class definition
require_once("DPXMLDataWrapper.php"); 

// _ instantiate a DBDataFether class object
$DPData = new DPDataFetcher(); 

$parentID = $_REQUEST["guid"];
//_ if no parameter recieved - die with no response
if (empty($parentID)) {die();}

$startPos = $_REQUEST["start"];
//_ if no parameter recieved - set default
if (empty($startPos)) {$startPos = 0;}

$pageSize = $_REQUEST["psize"];
//_ if no parameter recieved - set default
if (empty($pageSize)) {$pageSize = $_SESSION["DEF_PAGING_SIZE"];}

//_ fetch an object from Session
$Cache = new DPCachedData;

$Cache = &$_SESSION["CACHED_DATA_OBJECT"];

//_ retrieves raw data into an Data Item Set
$RURS = $DPData->GetAllDataForRoot($parentID); 

$Cache->m_rowSet = $RURS;
$Cache->m_rootGUID = $parentID;
$Cache->m_currentPosition = $startPos;

$_SESSION["CACHED_DATA_OBJECT"] = $Cache;

//_ irrelevant code ...

···································································································

[ testSession_2.php ]

 
	// _ requires DPCachedRowSet class definition
	require_once("library/DPCachedData.php"); 

session_start();

$obj=&$_SESSION["CACHED_DATA_OBJECT"];
print_r($obj);
echo "<hr />";
echo $obj->m_rootGUID . "<br />";
echo $obj->m_currentPosition . "<br />";
print_r($obj->m_rowSet);
$obj->m_rowSet->MoveFirst();
echo $obj->m_rowSet->Name . " EOF? " . $obj->m_rowSet->EOF;

The output:

stdClass Object ( [m_rowSet] => COM Object ( [0] => 0 ) [m_rootGUID] => {E3CB7B18-B218-4ACB-85EE-5007D20908AB} [m_currentPosition] => 0 )

{E3CB7B18-B218-4ACB-85EE-5007D20908AB}

COM Object ( [0] => 0 )
EOF?

in short the m_rowSet member gives NADA!!!

if anyadditional information is needed ask away!!!

any comment is appreciatate, thanks.

[yelvington]

I am not an object kind of guy.

But did you do this?

http://us4.php.net/manual/en/language.oop.serialization.php

[vadik_g]

thanks for the post:

Well yeah I tried it of course - same result.

What I understood is thet when u add an object to the session it gots serialized automaticly.

Anyway tried it - same result.

[jlpierce]

I am going to simplify the code but you can adapt it to your situation.

File thisclass.php

class thisclass { ..... } // a class definition

File test.php

require_once('thisclass.php');

session_start();

$obj = new thisclass;

// do something usefull with the class

session_register($obj);
/*
the above statement will automatically serialize the obj variable to the session
when the script ends.
*/

File test1.php

require_once('thisclass.php');

if ( isset($_SESSION['obj'] )
{
     $obj = $_SESSION['obj'];
}
else
{
     $obj = new thisclass;
}

// do something usefull with object

I hope this sheds some light on the subject.

John

[vadik_g]

Thanks for the post.

I tried this approach - same result.

Yes it serializes automatically the Object, but still the inner object returns empty.

I tested it with a new functionality:

dpCachedData.php

// ---------------------------------------------------------------------------------------
// class DPCachedData

// Doesn't have custom error handling.
// ---------------------------------------------------------------------------------------
class DPCachedData 
{
		var $m_rowSet; 				//_ DataItemSet object
		var $m_rowSet_Serialized; 	//
		var $m_rootGUID; 			//_	DIS' root GUID if available
		var $m_currentPosition; 	//_ Last browsing of the set started here 
		// -------------------------------------------------------------------------------
		// Constructor:
		// + registers the destuctor function
		// -------------------------------------------------------------------------------
		function DPCachedData() 
		{
			register_shutdown_function(array(& $this, "Close"));

		return true;
	} 
	// -------------------------------------------------------------------------------
	// Desctructor:
	// + closes & the XML objects and all
	// -------------------------------------------------------------------------------
	function Close() 
	{
		if (isset($this -> m_rowSet)) 
		{
				unset($this -> m_rowSet);
		} 

		if (isset($this -> m_rootGUID)) 
		{
				unset($this -> m_rootGUID);
		} 

		if (isset($this -> m_currentPosition)) 
		{
				unset($this -> m_currentPosition);
		} 

		return true;
	} 
	// -------------------------------------------------------------------------------
	// __sleep: serialization event
	// + serializes the inner DataItemSet object
	// -------------------------------------------------------------------------------
	function __sleep() 
	{
		$this -> m_rowSet_Serialized = serialize($this -> m_rowSet);
		return array("m_rowSet_Serialized", "m_rootGUID", "m_currentPosition");
	} 
	// -------------------------------------------------------------------------------
	// __wakeup: unserialization event
	// + unserializes the inner DataItemSet object
	// -------------------------------------------------------------------------------
	function __wakeup() 
	{
			$this -> m_rowSet = unserialize($this -> m_rowSet_Serialized);
	} 
} //_ EOC: DPCachedData

[jlpierce]

Originally posted by vadik_g
Thanks for the post.

I tried this approach - same result.

Yes it serializes automatically the Object, but still the inner object returns empty.

I tested it with a new functionality:

dpCachedData.php

// ---------------------------------------------------------------------------------------
// class DPCachedData

// Doesn't have custom error handling.
// ---------------------------------------------------------------------------------------
class DPCachedData 
{
		var $m_rowSet; 				//_ DataItemSet object
		var $m_rowSet_Serialized; 	//
		var $m_rootGUID; 			//_	DIS' root GUID if available
		var $m_currentPosition; 	//_ Last browsing of the set started here 
		// -------------------------------------------------------------------------------
		// Constructor:
		// + registers the destuctor function
		// -------------------------------------------------------------------------------
		function DPCachedData() 
		{
			register_shutdown_function(array(& $this, "Close"));

		return true;
	} 
	// -------------------------------------------------------------------------------
	// Desctructor:
	// + closes & the XML objects and all
	// -------------------------------------------------------------------------------
	function Close() 
	{
		if (isset($this -> m_rowSet)) 
		{
				unset($this -> m_rowSet);
		} 

		if (isset($this -> m_rootGUID)) 
		{
				unset($this -> m_rootGUID);
		} 

		if (isset($this -> m_currentPosition)) 
		{
				unset($this -> m_currentPosition);
		} 

		return true;
	} 
	// -------------------------------------------------------------------------------
	// __sleep: serialization event
	// + serializes the inner DataItemSet object
	// -------------------------------------------------------------------------------
	function __sleep() 
	{
		$this -> m_rowSet_Serialized = serialize($this -> m_rowSet);
		return array("m_rowSet_Serialized", "m_rootGUID", "m_currentPosition");
	} 
	// -------------------------------------------------------------------------------
	// __wakeup: unserialization event
	// + unserializes the inner DataItemSet object
	// -------------------------------------------------------------------------------
	function __wakeup() 
	{
			$this -> m_rowSet = unserialize($this -> m_rowSet_Serialized);
	} 
} //_ EOC: DPCachedData

[/B]

I was looking over your code snippet again, and I have some questions and comment:

1) Where is the data for the m_rowSet_Serialized, m_rootGUID, and m_currentPosition comming from?

2) Are you sure that the m_rowSet contains data prior to serialization?

Commnet: In your sleep function it appears that you are returning 3 quoted strings in the array and not the 3 variable.

I think you might need to do this:

return array($this->objvar1, $this->objvar2, $this->objvar3);

Just some more thoughts!

John Pierce

[vadik_g]

Hi, thanks for the reply.

Here's the answers to your questions:

1. m_rowSet_Serialized is a serialized version of m_rowSet.

m_rootGUID - i recive via POST and it contains valid value.

m_currentPosition - i recieve via POST and it contains valid values.

2. m_rowSet in turn I recieve from a COM object and it is a custom written Data Rowset, somewhat resembling ADO Recordset. It contains valid values prior to serialization and it contains them still after unserialization on the same php page, but not after I refresh the page or load another and "take" it from the session.

Other members, however retain their values ...

a reply to the comment:

actually it's a piece of code i adapted from php.net's manual
here's the link: http://us4.php.net/manual/en/language.oop.serialization.php

check post by evan at unixpimps dot org of 24-Aug-2002 10:26.

if u think it's errorneous please explain.

thanks.

[jlpierce]

Originally posted by vadik_g
Hi, thanks for the reply.

Here's the answers to your questions:

1. m_rowSet_Serialized is a serialized version of m_rowSet.

m_rootGUID - i recive via POST and it contains valid value.

m_currentPosition - i recieve via POST and it contains valid values.

2. m_rowSet in turn I recieve from a COM object and it is a custom written Data Rowset, somewhat resembling ADO Recordset. It contains valid values prior to serialization and it contains them still after unserialization on the same php page, but not after I refresh the page or load another and "take" it from the session.

Other members, however retain their values ...

a reply to the comment:

actually it's a piece of code i adapted from php.net's manual
here's the link: http://us4.php.net/manual/en/language.oop.serialization.php

check post by evan at unixpimps dot org of 24-Aug-2002 10:26.

if u think it's errorneous please explain.

thanks. [/B]

I still believe that you are passing back quoted strings, I would try prepending $this-> in front of the variable names and see what happens.

Also, if you are using php > 3 then to store an object in a session it is not necessary to serialize the object, php does it automatically when the script ends. Provided that you have session_registered('objvar'). Notice the absence of the $ in the session_register.

I have classes that use references to other instantiated objects, and provided I have session registered the main objvar all data is serialized automatically at script end. I do not use the serialize/unserialize functions at all.

That is all I can offer at this time, I hope it helps.

John

[vadik_g]

Thanks, John, I'll try everything you've told me to and post the results tomorrow [my time].

[vadik_g]

John, doesn't work, mate.

The inner object is getting lost when trying to fetch from Session [not right after it was registered].

i'll be trying different thing of all what i know already.

As I said to you I have a suspicion that the problem is due to the nature of the object - a recordset. i'll check it and post the results here.