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Examples

This JScript code in the function test() does the following: 

  <HTML>
   <BODY>
   <SCRIPT LANGUAGE="JScript">
   function foo()
   {
      // Create new element and assign the value 10
      this.Bar = 10;
   }

   function test()
   {
      // Construct new object
      Obj = new Object();

      // Create new element and assign function pointer
      Obj.Elem = foo;

      // Call Elem method ("this" == Obj)
      Obj.Elem();

      // Obj.Bar now exists
   }
   test();
   </SCRIPT>
   </BODY>
   </HTML>

A control placed on this same web page could obtain from the browser a dispatch pointer to the script engines. The control could then implement the function test(): 

  <HTML>
   <BODY>
   <SCRIPT LANGUAGE="JScript">
   function foo()
   {
      // Create new element and assign the value 10
      this.Bar = 10;
   }
   </SCRIPT>
   <OBJECT ID="test" <CLASSID="CLSID:9417DB5D-FA2A-11D0-8CB3-00C04FC2B085">>
   </OBJECT>
   </BODY>
   </HTML>

Code from the control "test" that does the same thing as the JScript function test(). Note that these dispatch calls are made into the 'running' JScript engine and change the state of the engine: 

  BOOL test(IDispatchEx *pdexScript)
   {
      HRESULT hr;
      VARIANT var;
      BSTR bstrName;
      DISPID dispid, putid;
      IDispatchEx *pdexObj;
      IDispatch   *pdispObj, *pdispFoo;
      DISPPARAMS dispparams, dispparamsNoArgs = {NULL, NULL, 0, 0};

      // Get dispatch pointer for "foo"
      bstrName = SysAllocString(OLESTR("foo"));
      pdexScript->GetDispID(bstrName, 0, &dispid);
      SysFreeString(bstrName);
      pdexScript->InvokeEx(dispid, LOCALE_USER_DEFAULT, 
         DISPATCH_PROPERTYGET, &dispparamsNoArgs, 
         &var, NULL, NULL);
      pdispFoo = var.pdispVal;

      // Create object by calling "Object" constructor
      bstrName = SysAllocString(OLESTR("Object"));
      pdexScript->GetDispID(bstrName, 0, &dispid);
      SysFreeString(bstrName);
      pdexScript->InvokeEx(dispid, LOCALE_USER_DEFAULT, 
         DISPATCH_CONSTRUCT, &dispparamsNoArgs, 
         &var, NULL, NULL);
      pdispObj = var.pdispVal;
      pdispObj->QueryInterface(IID_IDispatchEx, (void **)&pdexObj);

      // Create new element in object
      bstrName = SysAllocString(OLESTR("Elem"));
      pdexObj->GetDispID(bstrName, fdexNameEnsure, &dispid);
      SysFreeString(bstrName);

      // Assign "foo" dispatch pointer to element
      putid = DISPID_PROPERTYPUT;
      var.vt = VT_DISPATCH;
      var.pdispVal = pdispFoo;
      dispparams.rgvarg = &var;
      dispparams.rgdispidNamedArgs = &putid;
      dispparams.cArgs = 1;
      dispparams.cNamedArgs = 1;
      pdexObj->InvokeEx(dispid, LOCALE_USER_DEFAULT, 
         DISPATCH_PROPERTYPUTREF, &dispparams,
         NULL, NULL, NULL);

      // Invoke method with "this" pointer
      putid = DISPID_THIS;
      var.vt = VT_DISPATCH;
      var.pdispVal = pdispObj;
      dispparams.rgvarg = &var;
      dispparams.rgdispidNamedArgs = &putid;
      dispparams.cArgs = 1;
      dispparams.cNamedArgs = 1;
      pdexObj->InvokeEx(dispid, LOCALE_USER_DEFAULT,
         DISPATCH_METHOD, &dispparams,
      NULL, NULL, NULL);

      // Confirm that new element "Bar" is in object
      hr = pdexObj->GetNextDispID(fdexEnumAll, DISPID_STARTENUM, &dispid);
      while (hr != S_FALSE)
      {
         pdexObj->GetMemberName(dispid, &bstrName);
         if (!wcscmp(bstrName, OLESTR("Bar")))
            return TRUE;
         SysFreeString(bstrName);
         hr = pdexObj->GetNextDispID(fdexEnumAll, dispid, &dispid);
      }
      return FALSE;
   }

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