When using this method, function names and parameter datatypes are all resolved at compile time. A type library needs to be imported into Delphi. A type library is a language neutral description of all the objects and functions exposed by a server. All parameters need to be supplied, even when calling functions where the documentation states that some are optional. This enables many errors to be detected and corrected before ever running a program.
Performance is better than for late binding.
Due to the advantages of the second approach, the rest of the document demonstrates the basics of creating an application with early binding. All applications that use Excel Automation should use this technique unless there is a strong justification for not doing so. Preparing the Type Library. A pascal unit needs to be created from the type library file. The macro recorder allows VBA code to be created.