How To Modify the VC++ COMPLEXDB Sample to Work on a Web Page

MORE INFORMATION

1. Create a CDataSourceListener class that is derived from DataSourceListener (DataSourceListener is described in the ActiveX Control Writer's Kit).
2. Add the following code to the end of the ComplexCtl.cpp:

         class CDataSourceListener : public DataSourceListener
         {
            public:
              ULONG m_ulRefCount;
         CComplexCtl * m_pControl;
   
              CDataSourceListener(CComplexCtl * pControl):m_ulRefCount(0),
                 m_pControl(pControl){}
   
              STDMETHOD(QueryInterface)(REFIID iid, LPVOID * ppvObject)
              {
                if (IsEqualIID(__uuidof(IUnknown), iid) ||
                    IsEqualIID(__uuidof(DataSourceListener), iid))
                {
                    *ppvObject = this;
                    AddRef();
                    return S_OK;
                }
                else
                    return E_NOINTERFACE;
              }
   
         STDMETHOD_(ULONG, AddRef)()
         {
                return m_ulRefCount++;
         }
   
              STDMETHOD_(ULONG, Release)()
              {
                if (--m_ulRefCount == 0)
                {
                   delete this;
                   return 0;
                }
                else
                   return m_ulRefCount;
         }
   
              STDMETHOD(dataMemberChanged)(DataMember bstrDM)
              {
                m_pControl->UpdateControl();
                return S_OK;
              };
   
              STDMETHOD(dataMemberAdded)(DataMember bstrDM){return S_OK;};
   
              STDMETHOD(dataMemberRemoved)(DataMember bstrDM){return S_OK;};
   
         };
   						

3. Modify the CComplexCtl::putref_DataSource() method in CComplexCtl.cpp file to the following:

         STDMETHODIMP CComplexCtl::putref_DataSource(DataSource* pDataSource)
         {
            m_spDataSource = pDataSource;
            CDataSourceListener * pListener = new CDataSourceListener(this);
            // Listener object is deleted when it is released.
            m_spDataSource->addDataSourceListener(pListener);
         }
   						

4. Create the Web page to bind the data source object to the COMPLEXDB control. The following example uses the RDS.DataControl control to bind data to the COMPLEXDB control:

        <HTML>
         <HEAD>
         <TITLE>Sample Query Page</TITLE>
         </HEAD>
         <BODY>
         <CENTER>
         <H1>Sample Query Page</H1>
         <BR>
   
         <OBJECT ID="COMPLEXDB" WIDTH=600 HEIGHT=200
          CLASSID="CLSID:392BBDF0-06E1-11D1-8F8F-000000000000">
            <PARAM NAME=DataSource DATASRC=#ADC>
            <PARAM NAME=FieldName  VALUE="ProductName">
         </OBJECT>
   
         <BR>
         <OBJECT classid="clsid:BD96C556-65A3-11D0-983A-00C04FC29E33"
          ID=ADC HEIGHT=1 WIDTH = 1>
            <PARAM NAME="Server"   VALUE="http://myIISServer">
            <PARAM NAME="Connect"     VALUE="DSN=DataTables">
            <PARAM NAME="SQL"         VALUE="Select * from Products">
         </OBJECT>
         </BODY>
         </HTML>
   						

   NOTE: The Internet Client SDK documentation shows that you can use the following syntax:

         <OBJECT ID="COMPLEXDB" WIDTH=600 HEIGHT=200 Datasrc="#ADC"
           CLASSID="CLSID:392BBDF0-06E1-11D1-8F8F-000000000000">
   						

   These lines are supposed to connect the data source object with the particular object. This doesn't work with Internet Explorer 4.x and OLE DB data bound controls. You must set the data source by using the PARAM tag shown previously.