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3.3.2.2 Default methods
A dispinterface can have a default method or property, that is, one
that is called when the client does not specify the method
name. LuaCOM calls the default method when the object itself is used
as a function.
excel = luacom.CreateObject("Excel.Application")
excel.Visible = true
excel.Workbooks:Add()
-- Here we call the default method
-- notice we DID NOT use the colon, as
-- the object used is Sheets, not excel
sheet = excel.Sheets(1)
print(sheet.Name)
-- Here we also call the default method
-- We must supply the self parameter
sheets = excel.Sheets
sheet2 = sheets(2)
print(sheet2.Name)
-- Setting values
excel.Sheets(1).Name = "MySheet1"
excel:Quit()
This can be very useful when dealing with collections, as commonly they have a default Item property.
WARNING: one must be careful not to put the colon when using default methods of LuaCOM objects contained in table or in other LuaCOM objects (see the sample above).
Fabio Mascarenhas de Queiroz 2005-01-07