Help with session_is_registered

[AlMch]

Hi, 

I'm trying to make an old php script (won't work on anything over 5.3) run on php7. I'm not a coder by any means but get along by adapting examples I find on the web. I'm doing OK for the most part but am stuck finding what to replace session_is_registered with.

This is what it is currently: 

$pref = mysql_query("SELECT * FROM preferences WHERE ID = '0'",$connection)
or die(mysql_error());
$pdata = mysql_fetch_array($pref);
mysql_free_result($pref);

// I've already changed the above to:
// 
// pref = mysqli_query($connection,"SELECT * FROM preferences WHERE ID = '0'")
// or die(mysqli_error($connection));
// $pdata = mysqli_fetch_array($pref);
// mysqli_free_result($pref);
//
// Just wanted to show you the whole section in its orignal state.

// It's this line below that I'm not sure about...

if(!session_is_registered('defaultseasonid_') || !session_is_registered('defaultmatchtypeid_') || !session_is_registered('defaultlanguage_'))
	
{
	$_SESSION['defaultseasonid_'] = $pdata['DefaultSeasonID'];
	$_SESSION['defaultmatchtypeid_'] = $pdata['DefaultMatchTypeID'];
	$_SESSION['defaultlanguage_'] = $pdata['DefaultLanguage'];
	$defaultseasonid = $_SESSION['defaultseasonid_'];
	$defaultmatchtypeid = $_SESSION['defaultmatchtypeid_'];
	$defaultlanguage = $_SESSION['defaultlanguage_'];
}
else
{
	$defaultseasonid = $_SESSION['defaultseasonid_'];
	$defaultmatchtypeid = $_SESSION['defaultmatchtypeid_'];
	$defaultlanguage = $_SESSION['defaultlanguage_'];
}

session_unset();

Any pointers anybody can give me would be much appreciated.

TIA

[Barand]

Try reading the manual (session_is_registered) . After all, that's why they wrote it.

[AlMch]

9 minutes ago, Barand said:

Try reading the manual (session_is_registered) . After all, that's why they wrote it.

Yes I've looked at that but as far as I can see, it doesn't actually explain what to use instead. But thanks for your rather curt reply, here's me thinking I'd posted in the PHP Help forum. What a way to make newcomers feel welcome.

[Barand]

Well, I could repeat to you what the manual says or you could read it yourself. It seems more efficient to cut out the middle-man.

And the page I linked you to answers your question...

[AlMch]

And I've also tried that: 

if(isset($SESSION['defaultseasonid_']) || ($SESSION['defaultmatchtypeid_']) || ($SESSION['defaultlanguage_']))

But it doesn't seem to be pulling those default values into the session. PhpStorm says all the syntax is ok but it doesn't pull the required default values into the session. 

[Barand]

It's $_SESSION. not $SESSION

Have you called session_start() at the top of the script?

[Barand]

As of PHP 7.0 you could replace this code...

if(!session_is_registered('defaultseasonid_') || !session_is_registered('defaultmatchtypeid_') || !session_is_registered('defaultlanguage_'))
    
{
    $_SESSION['defaultseasonid_'] = $pdata['DefaultSeasonID'];
    $_SESSION['defaultmatchtypeid_'] = $pdata['DefaultMatchTypeID'];
    $_SESSION['defaultlanguage_'] = $pdata['DefaultLanguage'];
    $defaultseasonid = $_SESSION['defaultseasonid_'];
    $defaultmatchtypeid = $_SESSION['defaultmatchtypeid_'];
    $defaultlanguage = $_SESSION['defaultlanguage_'];
}
else
{
    $defaultseasonid = $_SESSION['defaultseasonid_'];
    $defaultmatchtypeid = $_SESSION['defaultmatchtypeid_'];
    $defaultlanguage = $_SESSION['defaultlanguage_'];
}

with ...

    $defaultseasonid = $_SESSION['defaultseasonid_'] ?? $pdata['DefaultSeasonID'];
    $defaultmatchtypeid = $_SESSION['defaultmatchtypeid_'] ?? $pdata['DefaultMatchTypeID'];
    $defaultlanguage = $_SESSION['defaultlanguage_'] ?? $pdata['DefaultLanguage'];

"??" is the "null coalesce" operator, so

$a = $b ?? $c ?? $d;

will set $a to the first of the three values that is not  null.

[AlMch]

Yep session_start is called. Looks like I missed out a ! so I now have this...

if(!isset($_SESSION['defaultseasonid_']) || ($_SESSION['defaultmatchtypeid_']) || ($_SESSION['defaultlanguage_']))

So, and excuse my ignorance, but I think that's saying use the defaultseasonid_ from the database if there isn't one already in the session? Now we're getting somewhere as this is working and bringing in a list of players for the current (default) season. However, a little later on in the script I have a couple of drop-downs to select from the list of available seasons and another with a list of matchtypes. Both these worked prior to adding the ! but now only the season drop-down is working. 

 

EDIT - posted this before seeing your last reply.

[Barand]

1 minute ago, AlMch said:

now only the season drop-down is working. 

That's the only one that you check with isset(). Should be

if ( !isset($_SESSION['defaultseasonid_']) || !isset($_SESSION['defaultmatchtypeid_']) || !isset($_SESSION['defaultlanguage_']) )

but the ?? method is a lot simpler.

[AlMch]

Barand - awesome. The ?? method has worked perfectly. 

There we go - I've learnt a bit more today, thank you!

[Barand]

3 hours ago, Barand said:

if ( !isset($_SESSION['defaultseasonid_']) || !isset($_SESSION['defaultmatchtypeid_']) || !isset($_SESSION['defaultlanguage_']) )

For the sake of completeness, an alternative way to write this is

if (!isset($_SESSION['defaultseasonid_'], $_SESSION['defaultmatchtypeid_'], $_SESSION['defaultlanguage_']))