Workflow 中做拒绝操作时强制输入拒绝信息

在做AP发票审批驳回时，客户要求必须强制输入拒绝原因，代码如下：

PROCEDURE Validate_Response
(
 Itemtype IN VARCHAR2,
 Itemkey IN VARCHAR2,
 Actid IN NUMBER,
 Funcmode IN VARCHAR2,
 Resultout IN OUT VARCHAR2
) IS

 l_Nid NUMBER;
 l_Approval_Comments VARCHAR2(2000);
 l_Next_Appr_Level NUMBER;
 l_Activity_Result_Code VARCHAR2(200);
 l_Activity_Result VARCHAR2(200);
 l_Activity VARCHAR2(100);
 v_Response_Reason VARCHAR2(50);
 l_Display_Name VARCHAR2(100);
 l_Role VARCHAR2(100);

BEGIN

 l_Activity := Wf_Engine.Getactivitylabel(Actid => Actid);

 IF (Funcmode IN ('RESPOND')) THEN

 l_Nid := Wf_Engine.Context_Nid;
 l_Activity_Result_Code := Wf_Notification.Getattrtext(l_Nid, 'RESULT');
 v_Response_Reason := Wf_Notification.Getattrtext(l_Nid, 'WF_NOTE');

 IF l_Activity_Result_Code = 'REJECTED' AND v_Response_Reason IS NULL THEN
 Resultout := 'ERROR: You must enter a rejection note.';
 Raise_Application_Error(-20000, 'ERROR: You must enter a rejection note.');
--RETURN;
 ELSIF l_Activity_Result_Code = 'REJECTED' AND v_Response_Reason IS NOT NULL THEN
--Do something if the notification is rejected and the rejection reason is entered by the approver
 NULL;
 END IF;

 Wf_Engine.Setitemattrtext(Itemtype => Itemtype,
 Itemkey => Itemkey,
 Aname => 'APPROVAL_RESULT',
 Avalue => l_Activity_Result_Code);
 Wf_Engine.Setitemattrtext(Itemtype => Itemtype,
 Itemkey => Itemkey,
 Aname => 'APPROVAL_COMMENTS',
 Avalue => v_Response_Reason);
 Resultout := 'COMPLETE:Reject';
 ELSE
 NULL;
 END IF;

EXCEPTION
 WHEN OTHERS THEN
 Resultout := SQLERRM;

END Validate_Response;