Re: [api-dev] multiple-inheritance interafces and method name clashes

[Rony G. Flatscher]

Mathias Bauer wrote: E.g., in the ooRexx support for UNO/OOo the connection-routine looks like: ------------- cut here ------------- ::routine UNO.connect public parse arg unoURL -- retrieve the argument, if any xContext=.UNO~Bootstrap~bootstrap -- get an initialized local UNO runtime environment if unoURL="" then -- no unoURL given, use default (local installation) return xContext -- return the context object (which can be used to get the service manager) -- use the received unoURL to establish a connection to the remote object uur= xContext~getServiceManager~createInstanceWithContext("com.sun.star.bridge.UnoUrlResolver", xContext) remoteObject = uur~XUnoUrlResolver ~resolve(unoURL) -- get the connection return remoteObject ------------- cut here ------------- Looking at the code (the tilde is the message operator, i.e. left of it is the receiving object, right of it the name of the message), there is no queryInterface() at all. However, wherever the name of an interface is used as a message name (like at the end of the code snippet, the message "XUnoUrlResolver"), the "under the covers" support will carry out the queryInterface(). Exactly that's what more or less what OOo Basic does. I agree that this is a very good compromise: it allows a qualified access without the hassle of separate "queryInterface" calls. Hmm, well, no, not really. OOo Basic gets the name of a method and then it starts to look for it, if not found, it'll look in the interfaces, first match wins, if I understand the behaviour correctly. The above is a little bit (but significantly!) different: it would not go out and look for methods in interfaces on its own at all. The programmer needs to denominate the interface, if its methods are to be used, otherwise a runtime error would occur, indicating that the intended method was not found. The point just is, that denominating the interface is unobstrusive in this case, as the programmer does not need to explicitly carry out the queryInterface(), rather the "under-the-covers" support for UNO (realized in the form of an ooRexx module for UNO) does this, alleviating the programmer. Probably it would be possible to do the same with OOo Basic, ie. add that behaviour there as well (and it should be possible without breaking existing code), e.g. uur.XUnoUrlResolver.resolve(unoURL) ... as an option to uur.resolve(unoURL) This at first may look like "syntax sugar", as the present behaviour would still be available. But if desired (as an additional suggestion to OOo Basic), one could add an OPTION to indicate that interfaces need to be explicitly denominated. Regards, ---rony