What are your suggestions? One option that I was thinking is to add a
boolean field in the message that determines if the list is empty or
not. What do you think?
On Jun 22, 1:21 pm, Marc Gravell <marc.grav...@gmail.com> wrote:
> Kenton is of course quite correct. There is no *native* distinction between
> a null list and an empty list in the raw protobuf data stream. There *are*
> some ways of working around that, to distinguish between the two, but not
> when using the code-generation from .proto.
>
> Marc
>
> On 22 June 2010 18:59, Kenton Varda <ken...@google.com> wrote:
>
>
>
>
>
> > Protocol Buffers has no concept of "null". Lists can be empty, but not
> > "null".
>
> > On Mon, Jun 21, 2010 at 6:35 PM, Manh Do <mdo...@gmail.com> wrote:
>
> >> I am working a project where we need to determine if a protobuf list
> >> have is null or not in the protocol buffer.
>
> >> The problem is the generated c# automatically instantiates the list.
>
> >> IE. Protocol:
> >> message B {
> >> repeated A MyList = 0;
> >> }
>
> >> Generated C#:
>
> >> private readonly global::System.Collections.Generic.List<A> _MyList =
> >> new global::System.Collections.Generic.List<A>();
> >> [global::ProtoBuf.ProtoMember(0, Name=@"MyList", DataFormat =
> >> global::ProtoBuf.DataFormat.Default)]
> >> public global::System.Collections.Generic.List<A> MyList
> >> {
> >> get { return _MyList ; }
> >> }
>
> >> The problem with this is I cannot determine if the list is null. I am
> >> using an empty list as a way to remove all objects.
>
> >> Is there a way where I can make the generator not automatically
> >> instantiate the list? Better yet, how do I check for default values in
> >> protocol buffer C#? I know you can check for
> >> 'default(typeof(MyType));'.
>
> >> Thanks for the help!
>
> >> -Manh
>
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> Regards,
>
> Marc
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