DOCUMENT:Q182598 12-MAY-1998 [vbwin] TITLE :HOWTO: Implement IObjectSafety in Visual Basic Controls PRODUCT :Microsoft Visual Basic for Windows PROD/VER:WINDOWS:5.0 OPER/SYS:WINDOWS KEYWORDS:vb5all vb5howto AXSDKControls InetSDKSafeControl ====================================================================== --------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Control Creation, Professional, and Enterprise Editions for Windows, version 5.0 --------------------------------------------------------------------- SUMMARY ======= This article shows you how to implement the IObjectSafety interface in Visual Basic controls to mark the controls safe for scripting and initialization. By default, Visual Basic controls use component category entries in the registry to mark the control safe for scripting and initialization. Implementing the IObjectSafety interface is the preferred method. This article contains all the code required to implement this interface in Visual Basic controls. Please keep in mind that a control should only be marked as safe if it is, in fact, safe. This article does not describe the details of marking controls as safe for scripting and initialization, it simply shows you how to do it in code. Please refer to the Internet Client SDK documentation for a detailed description of this. See "Safe Initialization and Scripting for ActiveX Controls" under the Component Development Section. MORE INFORMATION ================ In this article you will create a simple Visual Basic control and mark it safe for scripting and initialization. 1. Copy the following text in Notepad and save the file as OBJSAFE.ODL: [ uuid(C67830E0-D11D-11cf-BD80-00AA00575603), helpstring("VB IObjectSafety Interface"), version(1.0) ] library IObjectSafetyTLB { importlib("stdole2.tlb"); [ uuid(CB5BDC81-93C1-11cf-8F20-00805F2CD064), helpstring("IObjectSafety Interface"), odl ] interface IObjectSafety:IUnknown { [helpstring("GetInterfaceSafetyOptions")] HRESULT GetInterfaceSafetyOptions( [in] long riid, [in] long *pdwSupportedOptions, [in] long *pdwEnabledOptions); [helpstring("SetInterfaceSafetyOptions")] HRESULT SetInterfaceSafetyOptions( [in] long riid, [in] long dwOptionsSetMask, [in] long dwEnabledOptions); } } 2. From a command prompt, type the following command to generate a TLB file: MKTYPLIB objsafe.odl /tlb objsafe.tlb 3. From Visual Basic, create an ActiveX Control project. In the Properties box, change the name of the project to IObjSafety and the name of the control to DemoCtl. Put a CommandButton named cmdTest on the control. In the Click event handler of the cmdTest, put a MsgBox "Test" statement. 4. From your Visual Basic Project References, browse to and add the objsafe.tlb file created in step 2 5. Add a new module to your project with the following code and name the module basSafeCtl: Option Explicit Public Const IID_IDispatch = "{00020400-0000-0000-C000-000000000046}" Public Const IID_IPersistStorage = _ "{0000010A-0000-0000-C000-000000000046}" Public Const IID_IPersistStream = _ "{00000109-0000-0000-C000-000000000046}" Public Const IID_IPersistPropertyBag = _ "{37D84F60-42CB-11CE-8135-00AA004BB851}" Public Const INTERFACESAFE_FOR_UNTRUSTED_CALLER = &H1 Public Const INTERFACESAFE_FOR_UNTRUSTED_DATA = &H2 Public Const E_NOINTERFACE = &H80004002 Public Const E_FAIL = &H80004005 Public Const MAX_GUIDLEN = 40 Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _ (pDest As Any, pSource As Any, ByVal ByteLen As Long) Public Declare Function StringFromGUID2 Lib "ole32.dll" (rguid As _ Any, ByVal lpstrClsId As Long, ByVal cbMax As Integer) As Long Public Type udtGUID Data1 As Long Data2 As Integer Data3 As Integer Data4(7) As Byte End Type Public m_fSafeForScripting As Boolean Public m_fSafeForInitializing As Boolean Sub Main() m_fSafeForScripting = True m_fSafeForInitializing = True End Sub 6. From Project Properties, change the Startup Object to "Sub Main" in order to execute the Sub Main above. This is where you will specify the values of safe for scripting and/or initialization variables using the m_fSafeForScripting and m_fSafeForInitializing variables. 7. Open the code window of your control. Add the following line of code to the Declaration Section (right after Option Explicit or as the first): Implements IObjectSafety 8. Copy the following two procedures to your controls code: Private Sub IObjectSafety_GetInterfaceSafetyOptions(ByVal riid As _ Long, pdwSupportedOptions As Long, pdwEnabledOptions As Long) Dim Rc As Long Dim rClsId As udtGUID Dim IID As String Dim bIID() As Byte pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER Or _ INTERFACESAFE_FOR_UNTRUSTED_DATA If (riid <> 0) Then CopyMemory rClsId, ByVal riid, Len(rClsId) bIID = String$(MAX_GUIDLEN, 0) Rc = StringFromGUID2(rClsId, VarPtr(bIID(0)), MAX_GUIDLEN) Rc = InStr(1, bIID, vbNullChar) - 1 IID = Left$(UCase(bIID), Rc) Select Case IID Case IID_IDispatch pdwEnabledOptions = IIf(m_fSafeForScripting, _ INTERFACESAFE_FOR_UNTRUSTED_CALLER, 0) Exit Sub Case IID_IPersistStorage, IID_IPersistStream, _ IID_IPersistPropertyBag pdwEnabledOptions = IIf(m_fSafeForInitializing, _ INTERFACESAFE_FOR_UNTRUSTED_DATA, 0) Exit Sub Case Else Err.Raise E_NOINTERFACE Exit Sub End Select End If End Sub Private Sub IObjectSafety_SetInterfaceSafetyOptions(ByVal riid As _ Long, ByVal dwOptionsSetMask As Long, ByVal dwEnabledOptions As Long) Dim Rc As Long Dim rClsId As udtGUID Dim IID As String Dim bIID() As Byte If (riid <> 0) Then CopyMemory rClsId, ByVal riid, Len(rClsId) bIID = String$(MAX_GUIDLEN, 0) Rc = StringFromGUID2(rClsId, VarPtr(bIID(0)), MAX_GUIDLEN) Rc = InStr(1, bIID, vbNullChar) - 1 IID = Left$(UCase(bIID), Rc) Select Case IID Case IID_IDispatch If ((dwEnabledOptions And dwOptionsSetMask) <> _ INTERFACESAFE_FOR_UNTRUSTED_CALLER) Then Err.Raise E_FAIL Exit Sub Else If Not m_fSafeForScripting Then Err.Raise E_FAIL End If Exit Sub End If Case IID_IPersistStorage, IID_IPersistStream, _ IID_IPersistPropertyBag If ((dwEnabledOptions And dwOptionsSetMask) <> _ INTERFACESAFE_FOR_UNTRUSTED_DATA) Then Err.Raise E_FAIL Exit Sub Else If Not m_fSafeForInitializing Then Err.Raise E_FAIL End If Exit Sub End If Case Else Err.Raise E_NOINTERFACE Exit Sub End Select End If End Sub 9. Save your project and files. Make an OCX from your project. Your control now implements the IObjectSafety interface. You can test it be inserting the control in an HTM file. REFERENCES ========== Internet Client SDK - Component Development - Safe Initialization and Scripting for ActiveX Controls For additional information, please see the following article in the Microsoft Knowledge Base: ARTICLE-ID: Q161873 TITLE : HOWTO: Mark MFC Controls Safe for Scripting/Initialization Additional query words: safety scripting persistence initialization ====================================================================== Keywords : vb5all vb5howto AXSDKControls InetSDKSafeControl Version : WINDOWS:5.0 Platform : WINDOWS Issue type : kbhowto ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1998.