Oh, further: if you want to know what order it is using - the easiest is
probably just to do:
string proto = Serializer.GetProto<Product>();
and look at the .proto schema it generates. You can also interrogate the
MetaType and ValueMember instances (if you were doing it programatically,
this would be a good choice) but the above is much easier for ad-hoc
scenarios.
Marc
(protobuf-net)
On 15 July 2013 19:48, Marc Gravell <[email protected]> wrote:
> This is specifically a protobuf-net question.
>
> In short, yes - that is fine... ish. If you add the numbers manually
> ***and get them right***, then it will work. However, your example actually
> gets them wrong: the protobuf-net library specifically assumes an
> *alphabetical* order for the properties / fields when using ImplicitFields,
> because reflection does not guarantee any particular order - see the
> "Remarks" section on MSDN:
> http://msdn.microsoft.com/en-us/library/6ztex2dc.aspx and
> http://msdn.microsoft.com/en-us/library/kyaxdd3x.aspx
>
> So the order is actually: Id = 1, IsAvailable = 2, Name = 3, Quantity = 4
> - you would then add NewField1 and NewField2 as 5 and 6, presumably.
>
> Just to quote from the documentation on ImplicitFields, too:
>
> /// <summary>
> /// Specifies the method used to infer field tags for members of the type
> /// under consideration. Tags are deduced using the invariant alphabetic
> /// sequence of the members' names; this makes implicit field tags very
> brittle,
> /// and susceptible to changes such as field names (normally an isolated
> /// change).
> /// </summary>
>
>
> Marc
> (protobuf-net)
>
>
> On 15 July 2013 06:48, Pravesh Tanwar <[email protected]> wrote:
>
>> Hi All,
>>
>> I am currently using Protobuf serializer in my C# project. Currently I am
>> serializing my Objects using "
>> [ProtoContract(ImplicitFields = ImplicitFields.AllPublic)]". The
>> serialized objects are stored in database and deserialized when needed. I
>> have now landed in a position that requires me to add new DataMembers to
>> existing object. I want to be able to do this without breaking backward
>> compatibility (while deserializing) of my current serialized objects.
>>
>> Is there a way for me to check what order does the Protobuf
>> serialize/deserialize objects?
>>
>> e.g of the Object being serialized:
>>
>> [ProtoContract(ImplicitFields = ImplicitFields.AllPublic)]
>>
>> public class Product
>> {
>> [DataMember]
>> public int Id { get; set; }
>>
>> [DataMember]
>> public string Name { get; set; }
>>
>> [DataMember]
>> public double Quantity { get; set; }
>>
>>
>>
>> [DataMember]
>> public bool? IsAvailable { get; set; }
>>
>> }
>>
>> If I can know what order they are currently being serialized then I can
>> use the "Order" data member attribute and make sure that the additional
>> fields are ordered at the end. Hopefully this will retain backward
>> compatibility while deserializing. e.g:
>>
>>
>> public class Product
>>
>> {
>> [DataMember(Order = 1)]
>>
>> public int Id { get; set; }
>>
>>
>> [DataMember(Order = 2)]
>>
>> public double Quantity { get; set; }
>>
>>
>> [DataMember(Order = 3)]
>>
>>
>> public bool? IsAvailable { get; set; }
>>
>>
>>
>> [DataMember(Order = 4)]
>>
>> public string Name { get; set; }
>>
>>
>> [DataMember(Order = 5)]
>>
>> public string NewField1 { get; set; }
>>
>>
>> [DataMember(Order = 6)]
>>
>> public string NewField2 { get; set; }
>>
>> }
>>
>>
>> Any ideas?
>>
>> --
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>>
>>
>>
>
>
>
> --
> Regards,
>
> Marc
>
--
Regards,
Marc
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