Custom serialization support in windows phone

[Kunal Prime]

I want to use custom serialization for my windows phone 8 application. I know we have an XmlSerializer class available for data serialization but it do not fullfill my needs.

Why i need custom serialization.
I need to use custom serialization for maintaining compatibility between multiple revisions of my application. Say i have a model class, which contains 3 member variables in revision 1.0 but i add one more member variable to the class in revision 1.1. So i want data stored by 1.0 app to be compatible with revision 1.1 too. For which i will add version number to each of my model class and depending on version number i will process every field during serialization and desrialization process.

What i tried.?
I searched for a custom serialization API for c# and came through ISerializable Interface which completely fullfill my needs but unfortunately it is not suppoted on Windows Phone. Searching further i came across Data Contract Serialization. But Data Contract Serialization does not support processing every member variable separately.


So how can i achieve custom serialization on windows phone? Please help. Unable to proceed because of this problem. Quick response will be appreciated.

Regards

[to_pe]

Hi,

Take a look at OnDeserializedAttribute. From the documentation:

When applied to a method, specifies that the method is called immediately after deserialization of an object in an object graph. The order of deserialization relative to other objects in the graph is non-deterministic.

You could do some post-initialization code here.

If you really want a clean and robust solution, then you should build one for yourself. You can try binary serialization/deserialization with optional "version" property on the beginning of the entire block which will inform your deserialization method that some additional stuff may be necessary.

[wizard_hu_]

You may want something like "Version Tolerant Serialization" http://msdn.microsoft.com/en-us/libr...v=vs.100).aspx. I do not actually know it, just found with a simple search. Given that it mentions some "SoapFormatter", it may be available for XML serialization too.
If there is no built-in support, any XML parser can do the job: create the object with default values, then traverse the XML and set the fields of the object accordingly. Fields not mentioned in the XML will remain to contain their default values.

[Kunal Prime]

You may want something like "Version Tolerant Serialization" http://msdn.microsoft.com/en-us/libr...v=vs.100).aspx.

This looks useful. I have no idea how i missed it. Will look into it.

If there is no built-in support, any XML parser can do the job: create the object with default values, then traverse the XML and set the fields of the object accordingly. Fields not mentioned in the XML will remain to contain their default values.

This is what XmlSerializer do right.? So according to you if i initialize my new field to its default value then XmlSerializer will still deserialize old data without throwing exceptions??

[Kunal Prime]

If you really want a clean and robust solution, then you should build one for yourself. You can try binary serialization/deserialization with optional "version" property on the beginning of the entire block which will inform your deserialization method that some additional stuff may be necessary.

I guess robust solution is what i want. As wizard_hu_ pointed, will look into Binary Serialization (Version Tolerant Serialization)..

Regards

[wizard_hu_]

Ehm, sorry. When searching I have not checked WP availability. BinaryFormatter is reportedly unavailable for WP7. If you develop for WP8, that may be different.

[Kunal Prime]

Hi wizard_hu_ ,

You may want something like "Version Tolerant Serialization" http://msdn.microsoft.com/en-us/libr...v=vs.100).aspx.

Unable to use BinaryFormatter or SoapFormatter. I guess like ISerializable these API's too are removed from windows phone API bundle.

[Kunal Prime]

Ehm, sorry. When searching I have not checked WP availability. BinaryFormatter is reportedly unavailable for WP7. If you develop for WP8, that may be different.

Does not works for Windows phone 8 too.. Will check on Xml stuff and update soon.

[Loukt]

Have you tryed NewtonSoft's Json.NET librairy ? (you can get it from nuget), that's not XML as the name shows, but there is a JsonConvert.Serialization(objet) method which may help you do the job ( didn't try it, I only use Deserialization one)

[Kunal Prime]

Hi all,
I was using XmlSerializer earlier but as wizard_hu_ pointed out XmlSerializer can be used to support revision changes. i.e you can create parser extension methodes while deserializing you Xml to initilize missing fields with default values. Dont even need to store revision number(atleast in my case) and since XmlSerializer is a first party API its good to use it over any other third party library.

//gameList is your xml
var doc = XDocument.Parse(gameList);

var items = doc.Descendants(XNameConstants.Game).Select(entryElement => new Game()
{
Name = entryElement.Descendants(XNameConstants.First).Single().Value;
Points = entryElement.Descendants(XNameConstants.DriverPin).GetPointsInt32OrDefault();
});

//parser extension method
public Int32 GetPointsInt32OrDefault(this XElement element)
{
Int32 parsedValue = 10; //default value
return (element == null || !Int32.TryParse(element.Value, out parsedValue)) ? 0 : parsedValue;
}

Regards

[Kunal Prime]

Hi Loukt,

Have you tryed NewtonSoft's Json.NET librairy ? (you can get it from nuget), that's not XML as the name shows, but there is a JsonConvert.Serialization(objet) method which may help you do the job ( didn't try it, I only use Deserialization one)

This library seems much powerful then XmlSerializer. But since i had used XmlSerializer earlier using the same thing is easy for me than using a completely different stuff. If at all i will find any problems with XmlSerializer i will report. Thanks for you suggestions.

Regards

[theothernt]

For future reference, there's also ServiceStack.Text which is an incredibly fast JSON serialiser...

https://github.com/ServiceStack/ServiceStack.Text or via NuGet.

[Kunal Prime]

For future reference, there's also ServiceStack.Text which is an incredibly fast JSON serialiser...

https://github.com/ServiceStack/ServiceStack.Text or via NuGet.

Thank you theothernt. I will try it with a sample application.