diff --git a/sources/Application/DataModel/TriggerAndAction/TriggerOnObject.php b/sources/Application/DataModel/TriggerAndAction/TriggerOnObject.php
new file mode 100644
index 000000000..e11186c27
--- /dev/null
+++ b/sources/Application/DataModel/TriggerAndAction/TriggerOnObject.php
@@ -0,0 +1,229 @@
+<?php
+
+/**
+ * Class TriggerOnObject
+ */
+abstract class TriggerOnObject extends Trigger
+{
+    /**
+     * @throws \CoreException
+     * @throws \Exception
+     */
+    public static function Init()
+    {
+        $aParams = array
+        (
+            "category" => "grant_by_profile,core/cmdb",
+            "key_type" => "autoincrement",
+            "name_attcode" => "description",
+            "complementary_name_attcode" => ['finalclass', 'complement'],
+            "state_attcode" => "",
+            "reconc_keys" => ['description'],
+            "db_table" => "priv_trigger_onobject",
+            "db_key_field" => "id",
+            "db_finalclass_field" => "",
+        );
+        MetaModel::Init_Params($aParams);
+        MetaModel::Init_InheritAttributes();
+        MetaModel::Init_AddAttribute(new AttributeClass("target_class",
+            array("class_category" => "bizmodel", "more_values" => "User,UserExternal,UserInternal,UserLDAP,UserLocal", "sql" => "target_class", "default_value" => null, "is_null_allowed" => false, "depends_on" => array(), "class_exclusion_list" => "Attachment")));
+        MetaModel::Init_AddAttribute(new AttributeOQL("filter", array("allowed_values" => null, "sql" => "filter", "default_value" => null, "is_null_allowed" => true, "depends_on" => array())));
+
+        // Display lists
+        MetaModel::Init_SetZListItems('details', array('description', 'context', 'target_class', 'filter', 'subscription_policy', 'action_list')); // Attributes to be displayed for the complete details
+        MetaModel::Init_SetZListItems('list', array('finalclass', 'target_class', 'description')); // Attributes to be displayed for a list
+        // Search criteria
+        MetaModel::Init_SetZListItems('default_search', array('description', 'target_class'));  // Default criteria of the search banner
+        //		MetaModel::Init_SetZListItems('standard_search', array('name', 'target_class', 'description')); // Criteria of the search form
+    }
+
+    /**
+     * @throws \CoreException
+     */
+    public function DoCheckToWrite()
+    {
+        parent::DoCheckToWrite();
+
+        $sFilter = trim($this->Get('filter') ?? '');
+        if (strlen($sFilter) > 0) {
+            try {
+                $oSearch = DBObjectSearch::FromOQL($sFilter);
+
+                if (!MetaModel::IsParentClass($this->Get('target_class'), $oSearch->GetClass())) {
+                    $this->m_aCheckIssues[] = Dict::Format('TriggerOnObject:WrongFilterClass', $this->Get('target_class'));
+                }
+            } catch (OqlException $e) {
+                $this->m_aCheckIssues[] = Dict::Format('TriggerOnObject:WrongFilterQuery', $e->getMessage());
+            }
+        }
+    }
+
+    /**
+     * @throws \CoreException
+     */
+    public function ComputeValues()
+    {
+        parent::ComputeValues();
+
+        // Complementary name of a Trigger is manually built
+        //   - the Trigger finalclass code not translated
+        //   - an hardcoded text in english
+        //   - the target class code not translated for TriggerOnObject subclasses
+        $this->Set('complement', 'class restriction: ' . $this->Get('target_class'));
+    }
+
+
+    /**
+     * Check whether the given object is in the scope of this trigger
+     * and can potentially be the subject of notifications
+     *
+     * @param DBObject $oObject The object to check
+     *
+     * @return bool
+     * @throws \CoreException
+     */
+    public function IsInScope(DBObject $oObject)
+    {
+        $sRootClass = $this->Get('target_class');
+
+        return ($oObject instanceof $sRootClass);
+    }
+
+    /**
+     * @param $aContextArgs
+     *
+     * @throws \ArchivedObjectException
+     * @throws \CoreException
+     */
+    public function DoActivate($aContextArgs)
+    {
+        $bGo = true;
+        if (isset($aContextArgs['this->object()'])) {
+            /** @var \DBObject $oObject */
+            $oObject = $aContextArgs['this->object()'];
+            $bGo = $this->IsTargetObject($oObject->GetKey(), $oObject->ListPreviousValuesForUpdatedAttributes());
+        }
+        if ($bGo) {
+            parent::DoActivate($aContextArgs);
+        }
+    }
+
+    /**
+     * if the target class is Attachment, then the trigger is read-only
+     * @param $sAttCode
+     * @param $aReasons
+     * @param $sTargetState
+     * @return int
+     * @throws ArchivedObjectException
+     * @throws CoreException
+     */
+    public function GetAttributeFlags($sAttCode, &$aReasons = array(), $sTargetState = '')
+    {
+        // Force the computed field to be read-only, preventing it to be written
+        if ($this->Get('target_class') == 'Attachment') {
+            return OPT_ATT_READONLY;
+        }
+        return parent::GetAttributeFlags($sAttCode, $aReasons, $sTargetState);
+    }
+
+
+    public function DisplayBareHeader(WebPage $oPage, $bEditMode = false)
+    {
+        $aHeaderBlocks = parent::DisplayBareHeader($oPage, $bEditMode);
+        if ($this->Get('target_class') == 'Attachment') {
+            $oPage->AddUiBlock(\Combodo\iTop\Application\UI\Base\Component\Alert\AlertUIBlockFactory::MakeForWarning('', Dict::S('Class:TriggerOnObject:TriggerClassAttachment/ReadOnlyMessage')));
+            $oPage->add_ready_script("$('#UIMenuModify').hide();");
+        }
+
+        return $aHeaderBlocks;
+    }
+
+    /**
+     * Activate trigger based on attribute list given instead of changed attributes
+     *
+     * @param array $aContextArgs
+     * @param array|null $aAttributes if null default to changed attributes
+     *
+     * @throws \ArchivedObjectException
+     * @throws \CoreException
+     * @throws \MissingQueryArgument
+     * @throws \MySQLException
+     * @throws \MySQLHasGoneAwayException
+     * @throws \OQLException
+     * @since 3.1.1 3.2.0 N°6228
+     */
+    public function DoActivateForSpecificAttributes(array $aContextArgs, ?array $aAttributes)
+    {
+        if (isset($aContextArgs['this->object()'])) {
+            /** @var \DBObject $oObject */
+            $oObject = $aContextArgs['this->object()'];
+            if (is_null($aAttributes)) {
+                $aChanges = $oObject->ListPreviousValuesForUpdatedAttributes();
+            } else {
+                $aChanges = array_fill_keys($aAttributes, true);
+            }
+            if (false === $this->IsTargetObject($oObject->GetKey(), $aChanges)) {
+                return;
+            }
+        }
+        parent::DoActivate($aContextArgs);
+    }
+
+    /**
+     * @param $iObjectId
+     * @param array $aChanges
+     *
+     * @return bool True if the object of ID $iObjectId is within the scope of the OQL defined by the "filter" attribute
+     *
+     * @throws \CoreException
+     * @throws \MissingQueryArgument
+     * @throws \MySQLException
+     * @throws \MySQLHasGoneAwayException
+     * @throws \OQLException
+     */
+    public function IsTargetObject($iObjectId, $aChanges = array())
+    {
+        $sFilter = trim($this->Get('filter') ?? '');
+        if (strlen($sFilter) > 0) {
+            $oSearch = DBObjectSearch::FromOQL($sFilter);
+            $oSearch->AddCondition('id', $iObjectId, '=');
+            $oSearch->AllowAllData();
+            $oSet = new DBObjectSet($oSearch);
+            $bRet = ($oSet->Count() > 0);
+        } else {
+            $bRet = true;
+        }
+
+        return $bRet;
+    }
+
+    /**
+     * @param Exception $oException
+     * @param \DBObject $oObject
+     *
+     * @return void
+     *
+     * @uses \IssueLog::Error()
+     *
+     * @since 2.7.9 3.0.3 3.1.0 N°5893
+     */
+    public function LogException($oException, $oObject)
+    {
+        $sObjectKey = $oObject->GetKey(); // if object wasn't persisted yet, then we'll have a negative value
+
+        $aContext = [
+            'exception.class' => get_class($oException),
+            'exception.message' => $oException->getMessage(),
+            'trigger.class' => get_class($this),
+            'trigger.id' => $this->GetKey(),
+            'trigger.friendlyname' => $this->GetRawName(),
+            'object.class' => get_class($oObject),
+            'object.id' => $sObjectKey,
+            'object.friendlyname' => $oObject->GetRawName(),
+            'current_user' => UserRights::GetUser(),
+            'exception.stack' => $oException->getTraceAsString(),
+        ];
+
+        IssueLog::Error('A trigger did throw an exception', null, $aContext);
+    }
+}
\ No newline at end of file