Use extra fields to validate user add/edit on registration

main/admin/user_add.php

@@ -368,11 +368,47 @@ $html_results_enabled[] = $form->createElement('button', 'submit_plus', get_lang
 $form->addGroup($html_results_enabled);
 
 // Validate form
-if ($form->validate()) {
+$formValid = $form->validate();
+if ($formValid) {
     $check = Security::check_token('post');
     if ($check) {
         $user = $form->exportValues();
 
+        $extraFields = api_get_configuration_value('extra_fields_to_validate_on_user_registration');
+        if (!empty($extraFields) && isset($extraFields['extra_fields'])) {
+            $extraFieldList = $extraFields['extra_fields'];
+            foreach ($user as $key => $value) {
+                if (substr($key, 0, 6) == 'extra_') {
+                    $extra_value = Security::remove_XSS($value);
+                    $extra_field = substr($key,6);
+
+                    if(!empty($extra_value)) {
+                        if (in_array($extra_field, $extraFieldList)) {
+                            $extraValueExists = api_user_extra_field_validation($extra_field, $extra_value);
+                            if ($extraValueExists) {
+                                $formValid = false;
+
+                                $element = $form->getElement($key);
+                                if ($element) {
+                                    $attrs = ['style' => 'border-color: #a94442;'];
+                                    $form->updateElementAttr([$element], $attrs);
+                                }
+
+                                Display::addFlash(
+                                    Display::return_message(
+                                        get_lang('TheValueEntered ').$extra_field.get_lang('AlreadyExists'),
+                                        'error',
+                                        false
+                                    )
+                                );
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        if ($formValid) {
             $lastname = $user['lastname'];
             $firstname = $user['firstname'];
             $official_code = $user['official_code'];
@@ -498,7 +534,10 @@ if ($form->validate()) {
                 exit;
             }
         }
-} else {
+    }
+}
+
+if (!$formValid) {
     if (isset($_POST['submit'])) {
         Security::clear_token();
     }

main/admin/user_edit.php

@@ -432,6 +432,44 @@ $error_drh = false;
 // Validate form
 if ($form->validate()) {
     $user = $form->getSubmitValues(1);
+
+    $formValid = true;
+
+    $extraFields = api_get_configuration_value('extra_fields_to_validate_on_user_registration');
+    if (!empty($extraFields) && isset($extraFields['extra_fields'])) {
+        $extraFieldList = $extraFields['extra_fields'];
+        foreach ($user as $key => $value) {
+            if (substr($key, 0, 6) == 'extra_') {
+                $extra_value = Security::remove_XSS($value);
+                $extra_field = substr($key,6);
+
+                if(!empty($extra_value)) {
+                    if (in_array($extra_field, $extraFieldList)) {
+                        $extraValueExists = api_user_extra_field_validation($extra_field, $extra_value);
+                        if ($extraValueExists) {
+                            $formValid = false;
+
+                            $element = $form->getElement($key);
+                            if ($element) {
+                                $attrs = ['style' => 'border-color: #a94442;'];
+                                $form->updateElementAttr([$element], $attrs);
+                            }
+
+                            Display::addFlash(
+                                Display::return_message(
+                                    get_lang('TheValueEntered ').$extra_field.get_lang('AlreadyExists'),
+                                    'error',
+                                    false
+                                )
+                            );
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    if ($formValid) {
         $reset_password = (int) $user['reset_password'];
         if ($reset_password == 2 && empty($user['password'])) {
             Display::addFlash(Display::return_message(get_lang('PasswordIsTooShort')));
@@ -569,6 +607,7 @@ if ($form->validate()) {
         header('Location: user_list.php');
         exit();
     }
+}
 
 $actions = [
     Display::url(