Check if OLE object is installed

Problem/Question/Abstract:

How can I check if OLE object is installed?

Answer:

Sometimes in development if you use OLE automation of some obejct, your application will not work because application is not installed on client computer. For example, you use MS excel automation but MS Excel is not  installed.

You can easy check if OLE object is installed and correctly registered using CLSIDFromProgID function (for MS Excel as example only):

var
  ClassID: TCLSID;
  strOLEObject: string;
begin
  strOLEObject := 'Excel.Application';
  if (CLSIDFromProgID(PWideChar(WideString(strOLEObject)), ClassID) = S_OK) then
  begin

  end
  else
  begin

  end
end;

In same manner you can check any other required OLE object.