session_register

(PHP 4, PHP 5 < 5.4.0)

session_register — Enregistre une variable globale dans une session

Description

session_register ( mixed $name [, mixed $... ] ) : bool

session_register() enregistre toutes les variables de nom name dans la session courante. Le nombre de variables enregistrées est libre. Les noms peuvent être passés comme des chaînes, ou comme des tableaux contenant des chaînes ou des tableaux. Pour chaque nom, session_register() place la variable dans la session courante, pour la sauvegarde de fin de script.

Vous pouvez aussi créer une variable de session, simplement en ajoutant l'index approprié dans la variable $_SESSION.


<?php
// L'utilisation de session_register() est déconseillée
$barney = "Un gros dinosaure violet.";
session_register("barney");

// L'utilisation de $_SESSION est encouragée
$_SESSION["zim"] = "Un envahisseur d'une autre planète.";
?>

Si session_start() n'a pas été appelé avant cette fonction, un appel implicite à session_start() sans aucun paramètre sera fait. $_SESSION ne reproduit pas ce comportement et nécessite d'abord un appel à la fonction session_start().

Avertissement

Cette fonction est OBSOLÈTE à partir de PHP 5.3.0 et a été SUPPRIMÉE à partir de PHP 5.4.0.

Liste de paramètres

name: Le nom de la variable ou du tableau contenant les noms des variables ou d'autres tableaux.
...

Valeurs de retour

Cette fonction retourne TRUE en cas de succès ou FALSE si une erreur survient.

Notes

Attention

Si vous voulez que votre script fonctionne indépendamment de la configuration de la directive register_globals, vous devez utiliser la variable $_SESSION. Tous les éléments de $_SESSION sont automatiquement enregistrés. Si votre script utilise session_register(), il ne fonctionnera pas dans les environnements où register_globals est désactivée.

Note: register_globals : note importante

À partir de PHP 4.2.0, la valeur par défaut de la directive de configuration PHP register_globals vaut off. La communauté PHP décourage la dépendance à cette directive, et encourage l'utilisation d'autres moyens pour accéder aux données, tels que les superglobals.

Attention

Cette fonction enregistre une variable globale. Si vous enregistrez une variable globale dans une fonction, vous devez vous assurer de la rendre globale, avec le mot clé global ou le tableau $GLOBALS[], ou bien utiliser un des tableaux de session ci-dessous.

Attention

Si vous utilisez $_SESSION, n'utilisez pas session_register(), session_is_registered() et session_unregister().

Note:
Il n'est actuellement pas possible d'enregistrer des ressources dans les sessions. Par exemple, vous ne pouvez pas créer de connexion à une base de données, et stocker la connexion dans une variable de session. Elle ne sera pas valide lors de la prochaine page. Les fonctions PHP qui retournent des ressources sont identifiées avec le type resource dans leurs définitions. Une liste de fonctions qui retournent des ressources sont disponible dans l'annexe types de ressources.

Si $_SESSION est utilisé, assignez les variables à $_SESSION : i.e. $_SESSION['var'] = 'ABC';

Voir aussi

session_is_registered() - Vérifie si une variable est enregistrée dans la session
session_unregister() - Supprime une variable de la session
$_SESSION

add a note

User Contributed Notes 15 notes

down

Ezion oudpapierdoos at gmail dot com ¶

14 years ago


Below is a fix that may be included in older code to make it work with PHP6. 

When needed it recreates the functions

- session_register()

- session_is_registered()

- session_unregister()



The functions inside the function fix_session_register() are only available  after fix_session_register() has run.

Therefore in PHP<6 where there already is a session_register() nothing happens.



<?php

// Fix for removed Session functions

function fix_session_register(){

    function session_register(){

        $args = func_get_args();

        foreach ($args as $key){

            $_SESSION[$key]=$GLOBALS[$key];

        }

    }

    function session_is_registered($key){

        return isset($_SESSION[$key]);

    }

    function session_unregister($key){

        unset($_SESSION[$key]);

    }

}

if (!function_exists('session_register')) fix_session_register();

?>





[EDIT BY danbrown AT php DOT net: Bugfix provided by "dr3w" on 02-APR-2010: "its [sic] function_exists with an S at the end".]

down

rob at akrabat dot com ¶

14 years ago


if you remove session_register() calls and replace with $_SESSION assignments, make sure that it wasn't being used in place of session_start(). If it was, you'll need to add a call to session_start() too, before you assign to $_SESSION.

down

pike-php at kw dot nl ¶

6 years ago


There are a few compat functions for session_register here that had me tripped up. 

1) when registering a session var, the value of the global you are registering should *not* override an existing session value. that would defeat the purpose of the session. instead the global should be refered to the sessions value.

2) the global should become a reference to the sessions value, so that when you change the globals value later, the session variable should change too.

This is what I'm using now

<?php
if (!function_exists('session_register')) {
     function session_register($name){
        global $$name;
        if (!isset($_SESSION[$name])) {
            $_SESSION[$name] = $$name;
          } 
          $$name = &$_SESSION[$name]; 
      }
    }
?>

down

dee dot earley at icode dot co dot uk ¶

8 years ago


Something that hasn't really been touch on when migrating old code, is that changes to variables made AFTER the session_register() call are still included in the session state.
A lot of the implementations above only add the entry to $_SESSION[] at the point it's called.
If the old code relies on this behaviour, you will either need to have code called on exit to assign back to $_SESSION, or replace it in entirety with $_SESSION usage. With over 1000 uses of the session_ functions, this is a bit daunting!

down

david dot jufer at kirchenweb dot ch ¶

7 years ago


This code replaces the removed function "session_register" for PHP >= 5.4.0 
"session_start()" must be called before.

<?php

function session_register($name){
    if(isset($GLOBALS[$name])) $_SESSION[$name] = $GLOBALS[$name];
    $GLOBALS[$name] = &$_SESSION[$name];
}

?>

down

Scarab ¶

14 years ago


If you want to store an  object into the session, you have to check up that object can be serialized at all. 
For example, if your object contains aggregated PDO object (which can't be serialized), you will get an error and no data would be stored.

down

david dot demri at gmail dot com ¶

14 years ago


If you have an old code with a lot of call to the function session_register(), and you would like to make it compatible with PHP5 or PHP6, instead of rewriting all your code by replacing this function by $_SESSION['var']="val"; you could use the function set_session_vars(), that is used exactly the same way than session_register() (but there is no implicit call to session_start() ).

<?php
function set_session_vars() {
    $nb_args=func_num_args();
    $arg_list=func_get_args();
    for($i=0;$i<$nb_args;$i++) {
        global $$arg_list[$i];
        $_SESSION[$arg_list[$i]] = $$arg_list[$i];
    }
}
?>

down

mikej ¶

19 years ago


I've noticed that if you try to assign a value to a session variable with a numeric name, the variable will not exist in future sessions.
For example, if you do something like:
session_start();
$_SESSION['14'] = "blah";
print_r($_SESSION);

It'll display:
Array ( [14] => "blah" )

But if on another page (with same session) you try
session_start();
print_r($_SESSION);

$_SESSION[14] will no longer exist.

Maybe everyone else already knows this, but I didn't realize it until messing around with a broken script for quite a while.

down

-2

yarco dot w at gmail dot com ¶

13 years ago


You *MUST* notice that

session_register($var)

*IS NOT* 

$_SESSION[$var] = $$var;

it is 

if (!isset($_SESSION[$var]))
  $_SESSION[$var] = $$var;

when migrating from old style code.

down

-3

tecnico at overant dot com ¶

10 years ago


If you have many websites with these functions in the source code (like me) you can include the following functions in some kind of include.php that you have:

function session_register($session)
{
  //
}

function session_unregister($session)
{
  unset($_SESSION[$session]);
}

In this way the PHP interpreter detects the functions and do not return the error, and the maintenance work is minimized.

down

-3

baldanders ¶

19 years ago


If you are using sessions and use session_register()  to register objects, these objects are serialized automatically at the end of each PHP page, and are unserialized automatically on each of the following pages. This basically means that these objects can show up on any of your pages once they become part of your session.

down

-3

klein at sup4u dot de ¶

12 years ago


in addition to function set_session_vars instead of replacing all $var with $_SESSION['var'],

 you could get all set session-vars in prevoius scripts with this function



<?php

function get_session_vars() {

    $nb_args=func_num_args();

    $arg_list=func_get_args();

    for($i=0;$i<$nb_args;$i++) {

        global $$arg_list[$i] = $_SESSION[$arg_list[$i]];

    }

}

?>

down

-3

martijn at brothersinart dot net ¶

18 years ago


Please note that if you use a "|" sign in a variable name your entire session will be cleared, so the example below will clear out all the contents of your session. 

<?php
session_start();
$_SESSION["foo|bar"] = "foo";
?>

It took me quite some time finding out why my session data kept disappearing. According to this bugreport this behaviour is intended.
http://bugs.php.net/bug.php?id=33786

down

-5

guideng at unlv dot nevada dot edu ¶

17 years ago


Make sure you put session_start() at the beggining of your script.

My sessions kept unsetting and I finally figured out why.

On my script, session_start() has to be said and uses cookies to set the session. 

But I was outputting html prior to calling session_start(), which prevented it from succeeding becouse it uses the header function to place the cookies.

Once html has been outputed, session_start() can't use the header function to set cookies, hence session_start() fails and no session can be started.

down

-7

kavih7 at yahoo dot com ¶

14 years ago


For those of you who use this function (session_register that is), even though the manual does specify that this function implicitly calls session_start(), I just wanted to reiterate that fact. It is also important to know that if you ever switch from session_register to using $_SESSION, make sure to call session_start before adding items to the $_SESSION variable, because unlike session_register, no implicit call to session_start is done.

Another reason I explain this is because I ran into a problem in which you can add items to the $_SESSION variable all you want, but if session_start is not called before adding them, they will not actually be saved to the session. Using the same code, though, and replacing the $_SESSION assignments with session_register without calling session_start WILL save that info to the session.

It would be nice to have PHP check for writes to the $_SESSION variable and complain with a warning if session_start hasn't been called.

add a note