diff --git a/sources/FormType/Orm/AttCodeGroupByType.php b/sources/FormType/Orm/AttCodeGroupByType.php
index e59f21dc5..531012d3a 100644
--- a/sources/FormType/Orm/AttCodeGroupByType.php
+++ b/sources/FormType/Orm/AttCodeGroupByType.php
@@ -12,7 +12,6 @@ use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\ChoiceType as SymfonyChoiceType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Form\FormEvent;
-use Symfony\Component\Form\FormInterface;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 
 class AttCodeGroupByType extends AbstractType
@@ -39,24 +38,19 @@ class AttCodeGroupByType extends AbstractType
 			->setAllowedTypes('hook_type', 'string');
 	}
 
-	public static function BuildSubField(FormInterface $oForm, string $sName, array $aData, array $aFormOptions = []): void
-	{
-		\IssueLog::Info('AttCodeGroupByType BuildSubField data: '.var_export($aData, true));
-
-		$aFormOptions['choices'] = self::GetGroupByOptions($aData['query']);
-		$aFormOptions['multiple'] = false;
-		$oForm->add($sName, AttCodeGroupByType::class, $aFormOptions);
-	}
-
-	protected static function GetGroupByOptions($sOql)
+	protected function GetGroupByOptions($sClassOrOql)
 	{
 		$oModelReflection = new \ModelReflectionRuntime();
 
 		$aGroupBy = array();
 		try
 		{
-			$oQuery = $oModelReflection->GetQuery($sOql);
-			$sClass = $oQuery->GetClass();
+			if ($oModelReflection->IsValidClass($sClassOrOql)) {
+				$sClass = $sClassOrOql;
+			} else {
+				$oQuery = $oModelReflection->GetQuery($sClassOrOql);
+				$sClass = $oQuery->GetClass();
+			}
 			foreach($oModelReflection->ListAttributes($sClass) as $sAttCode => $sAttType)
 			{
 				// For external fields, find the real type of the target
@@ -110,4 +104,29 @@ class AttCodeGroupByType extends AbstractType
 		}
 		return array_flip($aGroupBy);
 	}
+
+	public function BuildOptions(array $aUserOptions, array $aModelData): ?array
+	{
+		$oModelReflection = new \ModelReflectionRuntime();
+		$sClassOrOql = $aModelData[$aUserOptions['source_class']];
+		if ($oModelReflection->IsValidClass($sClassOrOql)) {
+			$sClass = $sClassOrOql;
+		} else {
+			try {
+				$oQuery = $oModelReflection->GetQuery($sClassOrOql);
+			} catch (Exception $e) {
+				return null;
+			}
+			$sClass = $oQuery->GetClass();
+		}
+		$aFormOptions['choices'] = $this->GetGroupByOptions($sClass);
+		$aFormOptions['multiple'] = false;
+
+		return $aFormOptions;
+	}
+
+	public function GetPrerequisites(array $aUserOptions): ?array
+	{
+		return [$aUserOptions['source_class']];
+	}
 }
\ No newline at end of file
diff --git a/sources/FormType/Orm/ValuesFromAttcodeType.php b/sources/FormType/Orm/ValuesFromAttcodeType.php
index 47ae54923..d4f56c270 100644
--- a/sources/FormType/Orm/ValuesFromAttcodeType.php
+++ b/sources/FormType/Orm/ValuesFromAttcodeType.php
@@ -11,12 +11,13 @@ use Symfony\Component\Form\Extension\Core\Type\ChoiceType as SymfonyChoiceType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Form\FormEvent;
 use Symfony\Component\Form\FormEvents;
-use Symfony\Component\Form\FormInterface;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 use utils;
 
 class ValuesFromAttcodeType extends AbstractType
 {
+
+
 	public function buildForm(FormBuilderInterface $builder, array $options)
 	{
 		$builder->addEventListener(FormEvents::PRE_SET_DATA, function (FormEvent $event) {
@@ -44,18 +45,22 @@ class ValuesFromAttcodeType extends AbstractType
 	    $resolver->setDefault('attr', ['class' => 'ibo-input ibo-input-select']);
     }
 
-	public static function BuildSubField(FormInterface $oForm, string $sName, array $aData, array $aFormOptions = []): void
+	public function BuildOptions(array $aUserOptions, array $aModelData): ?array
 	{
-		\IssueLog::Info("ValuesFromAttcodeType BuildSubField data: ".var_export($aData, true));
-
-
-		if (utils::IsNullOrEmptyString($aData['group_by'] ?? null)) {
-			return;
+		$sAttCode = $aModelData[$aUserOptions['source_attcode']] ?? null;
+		if (utils::IsNullOrEmptyString($sAttCode)) {
+			return null;
 		} else {
 			$oModelReflection = new \ModelReflectionRuntime();
-			$oQuery = $oModelReflection->GetQuery($aData['query']);
-			$sClass = $oQuery->GetClass();
-			$sAttCode = $aData['group_by'];
+			$sClass = $aModelData[$aUserOptions['source_class']];
+			if (! $oModelReflection->IsValidClass($sClass)) {
+				try {
+					$oQuery = $oModelReflection->GetQuery($sClass);
+				} catch (\Exception $e) {
+					return null;
+				}
+				$sClass = $oQuery->GetClass();
+			}
 			if (\MetaModel::IsValidAttCode($sClass, $sAttCode)) {
 				$aAllowed = $oModelReflection->GetAllowedValues_att($sClass, $sAttCode);
 				if (is_array($aAllowed))
@@ -72,7 +77,14 @@ class ValuesFromAttcodeType extends AbstractType
 		$aFormOptions['multiple'] = true;
 		$aFormOptions['required'] = false;
 
-		$oForm->add($sName, ValuesFromAttcodeType::class, $aFormOptions);
+		return $aFormOptions;
 	}
 
+	public function GetPrerequisites(array $aUserOptions): ?array
+	{
+		return [
+			$aUserOptions['source_class'],
+			$aUserOptions['source_attcode'],
+		];
+	}
 }
\ No newline at end of file