Can't display Extra field (Date of birth) when logged in as Registered user

Question

I'm pretty new to Joomla, so sorry if this sounds silly.

I am using Extra Field "Date of Birth" from UserProfile in this code:

jimport( 'joomla.user.helper' );  
$user = JFactory::getUser();  
$userId = $user->id;  
$userProfile = JUserHelper::getProfile( $userId );  
$dob = $userProfile->profile['dob'];  
echo "dob = " . $dob ;  
echo "authorise =" . $user->authorise('core.admin', 'com_component');

Although $dob displays fine when logged in as a Super User, it won't show when logged in as a registered user.

So I'd like to display this field at a "basic non-administrator" level if it's possible.

Is there a way to do it? Or shall I temporarily change the User type to be able to access this field (I would obviously prefer not to...)?

---

Following the responses from mickmackusa and Sharky : Thank you so much for your answers. I'm pretty sure the registered user has a date set up, since it shows when turned into "Super User".

To help see better what's happening, I've changes the code a little :

jimport( 'joomla.user.helper' ); 
$user = JFactory::getUser();

echo "<br>--debug--";
echo "<br> id = " . $user->id ;
echo "<br> name = " . $user->name ;
echo "<br> username = " . $user->username ;

$isAdmin = $user->get('isRoot');
if ($isAdmin) {
echo '<br>You are an Administrator';
}
else  {
echo '<br>You are not Administrator';
}


$userId = $user->id; 
$userProfile = JUserHelper::getProfile( $userId );

$dob = $userProfile->profile['dob'];
echo "<br> dob = " . $dob ;
echo "<br> authorise =" . $user->authorise('core.admin', 'com_component');

echo "<br>var_dump = " . $userProfile; //var_dump(JUserHelper::getProfile( $userId ));

echo "<br>--debug--<br>";

And here's what I get:

1. When logged as Super User:

This code displays:

2. When logged as Adherent:

The same code displays:

---

When logged in as a SuperUser, var_dump(JUserHelper::getProfile( $userId )); says:

 object(Joomla\CMS\Object\CMSObject)#656 (3) {
     ["_errors":protected]=> array(0) { }
     ["id"]=> string(4) "2399"
     ["profile"]=> array(1) {
         ["dob"]=> string(19) "2020-07-28 00:00:00"
     }
 }

When logged as Adherent, the same code says:

object(Joomla\CMS\Object\CMSObject)#1412 (2) {
    ["_errors":protected]=> array(0) { }
    ["id"]=> string(4) "2399"
}

Answer 1

Whenever you call JUserHelper::getProfile() the code in that function triggers a Joomla event 'onContentPrepareData' to which the Joomla user plugin User - Profile subscribes. This plugin adds in the profile data which has been stored for this user and returns it as an array.

However, plugins have an Access field which controls which User Groups have viewing access to that plugin. So if for example the Access is set to Super Users, then only users whose User Group(s) belongs to the Super Users Viewing Access Level will be able to include that plugin. For other users running the same code, the plugin will not be included, and the profile data won't be made available.

To fix the issue go to Extensions / Plugins and find the User - Profile plugin. Click on it to edit it and set the Access field to Public (or whatever is appropriate for your case).