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;