>
> > I need to rewrite this class whenever schema is modified which I prefer
> to avoid.
And if I provided a custom serialization API, you'd need to maintain
*that *when
your schema changes, with the additional overhead that you'd have to worry
about some protobuf knowledge too. Or (perhaps more likely) I'd need to
spend quite some time devising a custom serializer API that is usable
without needing to know too much about the actual wire spec.
Another way of looking it is: your DTO model changes will *probably* be
relatively uncommon and pretty simple additions of new members (otherwise
you have other problems); the maintenance to add support for an extra
member should be minimal.
tl;dr; a custom serialization API is something I can look at *at some point*,
but it is not at the top of my list. And I'm still not convinced it is
desirable or advantageous, so *looking at it* isn't a guarantee of
*implementing
it.*
Marc
On 2 August 2012 05:06, Shail <shailendranalw...@gmail.com> wrote:
> Thanks Marc for Solution as well as detail explanation with test code. I
> really appreciate your support and effort.
>
> But in my context, as I mentioned above "Param" class is auto generated.So
> if I write ParamSurrogate , I need to rewrite this class whenever schema
> is modified which I prefer to avoid.
>
> Just wanted to know, like XML custom serialization,Is it feasible to
> write custom serialization for ProtoBuffer?
>
>
> Regards
> Shailendra
>
> On Wednesday, 1 August 2012 12:58:26 UTC+5:30, Marc Gravell wrote:
>>
>> Firstly, I must emphasise that everything here relates to protobuf-net,
>> not to the more general "protobuf" implementations.
>>
>> Yes, that is doable, via a combination of configuration at runtime, and a
>> "surrogate".
>>
>> Firstly: what is a "surrogate" here: well, the layout of Param, with
>> "object" etc, is not very protobuf-net friendly, so protobuf-net allows you
>> to write a separate, more-suitable-for-**serialization type, and flip
>> between them at will. To do this, protobuf-net uses the .NET conversion
>> operators (implicit or explicit), for example:
>>
>> [ProtoContract]
>> public class ParamSurrogate
>> {
>> [ProtoMember(1)]
>> public FloatData FloatData { get; set; }
>> // TODO: other types here
>>
>> public static implicit operator ParamSurrogate(Param value)
>> {
>> if (value == null) return null;
>> var surrogate = new ParamSurrogate();
>> if(value.Item != null)
>> {
>> surrogate.FloatData = value.Item as FloatData; //
>> will be null if not this
>> // TODO: other types here
>> }
>> return surrogate;
>> }
>> public static implicit operator Param(ParamSurrogate value)
>> {
>> if (value == null) return null;
>> var param = new Param();
>> if (value.FloatData != null) param.Item = value.FloatData;
>> // TODO: other types here
>> return param;
>> }
>> }
>>
>> Note that for convenience I'm using attributes to describe the
>> protobuf-net options for the surrogate, but that could also be avoided if
>> necessary. Note that we also need to tell protobuf-net to *use* that
>> surrogate whenever it sees a Param, which can be done via:
>>
>> // configure model (do once at app startup)
>> var model = RuntimeTypeModel.Default;
>> model.Add(typeof(Param), false).SetSurrogate(typeof(**
>> ParamSurrogate));
>>
>> Now, the FloatData is not actually too problematic - simple values are
>> arrays are fine. All we need to do is tell it about the members we want to
>> serialize, and which keys to use. This is as simple as (continuing that
>> initial configuration):
>>
>> model.Add(typeof (FloatData), false).Add("Ranges",
>> "AdjustValue", "Values");
>> //TODO: other types here
>>
>> which gives the 3 members the keys 1, 2, 3 respectively.
>>
>> We can test this:
>>
>> // test data
>> var param = new Param
>> {
>> Item = new FloatData
>> {
>> AdjustValue = 123.45F,
>> Ranges = new float[] { 1.0F, 2.4F },
>> Values = new float[] { 7.21F, 19.2F }
>> }
>> };
>> // note the fallowing is the same as Serializer.DeepClone,
>> since
>> // model === RuntimeTypeModel.Default
>> var clone = (Param) model.DeepClone(param);
>> Assert.AreNotSame(clone, param, "Different instance");
>> Assert.IsInstanceOfType(**typeof(FloatData), clone.Item,
>> "Data type");
>> var data = (FloatData) clone.Item;
>> Assert.AreEqual(123.45F, data.AdjustValue);
>> Assert.AreEqual(2, data.Ranges.Length);
>> Assert.AreEqual(1.0F, data.Ranges[0]);
>> Assert.AreEqual(2.4F, data.Ranges[1]);
>> Assert.AreEqual(2, data.Values.Length);
>> Assert.AreEqual(7.21F, data.Values[0]);
>> Assert.AreEqual(19.2F, data.Values[1]);
>>
>> Which all works fine, demonstrating that we have serialized and
>> deserialized the data correctly.
>>
>> Marc
>>
>>
>>
>> On 1 August 2012 07:52, Shail <shailendranalw...@gmail.com> wrote:
>>
>>> Hi Marc,
>>> Here FloatData, StringData,IntData,Int64Data,**CompositeData are custom
>>> classes like below is the defination of FloatData class:
>>>
>>> public class FloatData
>>> {
>>>
>>> /// <remarks/>
>>> [System.Xml.Serialization.**XmlArrayItemAttribute("item",
>>> IsNullable = false)]
>>> public float[] Ranges;
>>>
>>> /// <remarks/>
>>> [System.Xml.Serialization.**XmlAttributeAttribute()]
>>> public System.Single AdjustValue;
>>>
>>>
>>> /// <remarks/>
>>> [System.Xml.Serialization.**XmlAttributeAttribute()]
>>> public System.Single[] Values;
>>> }
>>>
>>> Regards
>>> Shailendra
>>>
>>> On Wednesday, 1 August 2012 11:51:01 UTC+5:30, Marc Gravell wrote:
>>>>
>>>> And in this model, what is FloatData, StringData, IntData, etc?
>>>>
>>>> This is certainly solvable with protobuf-net, but to do a complete
>>>> example I'd need to see those additional types.
>>>>
>>>> Marc
>>>> (protobuf-net)
>>>>
>>>> On 31 July 2012 14:14, Shail <shailendranalw...@gmail.com> wrote:
>>>>
>>>>> public class Param
>>>>> {
>>>>>
>>>>> /// <remarks/>
>>>>> [System.Xml.Serialization.**XmlE**lementAttribute("**FloatData",
>>>>> typeof(FloatData))]
>>>>> [System.Xml.Serialization.**XmlE**lementAttribute("**StringData",
>>>>> typeof(StringData))]
>>>>> [System.Xml.Serialization.**XmlE**lementAttribute("IntData",
>>>>> typeof(IntData))]
>>>>> [System.Xml.Serialization.**XmlE**lementAttribute("**Int64Data",
>>>>> typeof(Int64Data))]
>>>>> [System.Xml.Serialization.**XmlE**lementAttribute("**
>>>>> CompositeData**", typeof(CompositeData))]
>>>>> *public object Item;*
>>>>> .....
>>>>> ....
>>>>> }
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Regards,
>>>>
>>>> Marc
>>>>
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>>
>>
>>
>> --
>> Regards,
>>
>> Marc
>>
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