Hi Kenton, Sorry the parameter classes are legacy code and persisted to the DB as well. So I have to figure out what's the best approach defining my proto classes.
What I see is that there is the way of using extensions in the proto files. As far as I understand it is an extension of members (an not classes) in another proto file. Correct? So in my case the files in OStringParameterMessage.proto and OLongParameterMessage.proto extends OParameterMessage.proto with a member "value" of type string and int64. The OListParameterMessage.proto then extends it with a member value of type List (containing OParameterMessage.OParameter instances). In the OListParameter.writeObject() I build OParameter messages. But wouldn't there be a problem since the value is either of type String or Quantity (depending on the subclass of OParameter)? Probably I have to define different member names. Tai On 5 Aug., 03:05, Kenton Varda <ken...@google.com> wrote: > Can you just have the OParameter message contain optional fields of type > string and int64, where only one of the two is ever set? Then don't have > specific types corresponding to OStringParameter and OLongParameter. > > On Tue, Aug 4, 2009 at 5:07 PM, Tai <maitai.tru...@gmail.com> wrote: > > > Hi, > > > I have an (abstract) class: > > - OParameter with a member String key > > > Now there are also two subclasses of OParameter: > > - OStringParameter with a member String value > > - OLongParameter with a member long value > > > By using Protocol Buffers I define the proto files: > > - OParameterMessage.proto > > - OStringParameterMessage.proto > > - OLongParameterMessage.proto > > > The files are independent from each other (no extension is used). As > > far as I understand this is how Protocol Buffers should be used. All > > classes (OParameter, OStringParameter and OLongParameter) then > > implements the writeObject() and readObject() and each class just uses > > their Protocol message and sets their members. Like: > > - Class OStringParameter.writeObject() builds a message and sets only > > its member (value) > > - The superclass OParameter.writeObject() builds a message and sets > > only its member (key) > > > The same goes for the readObject(). > > > Okay. So far so good. But now I have a class called OListParameter and > > its member (value) is a list of OParameter containing instances of > > both types: OStringParameter and OLongParameter. > > > How do I describe this in a proto file? > > > Thanks Tai --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~----------~----~----~----~------~----~------~--~---
