Serialization and Backward Compatibility

Question

Hi,
We have an application in which we persist data to a flat file. For persisting we are using .net serialization with SOAP Formatter. Now the problem what we are facing is as follows.
Problem Statement:
Recently we have re-factored our source code i.e modifying project structure, renaming namespaces, renaming class names, adding or deleting properties. Can any one suggest a solution to handle the de-serialization issue while using the files which are persisted
by old version of the application.
Thanks,
Manohar

Answer 1

You could create/keep a project with the entity classes that you used to persist the data to your flat files. These would not contain any behavior and would only be used for deserializing and serializing from/to your flat files. You could put a facade in
front of this and treat it like a service. Your new project/code would call the facade to retrieve and write to the old structures. Then you could continue to grow/refactor your new code base without having to worry about the dependency on the persisted file
scheme.
On a side note the default SOAP formatter takes up a lot of wasted space in files and data contracts alike and can be too tightly coupled to your code in my opinion. If you do ever consider switching you could go to something like:
the XmlSerializer which gives your more control over how and what is persisted by way of attributes
a JSon serializer which is even more light weight and flexible
-Igor