ADO.NET Data Services Advanced Topics - Custom proxy based on T4 templates
1. Introduction
This is the first article of my series about deep dive into ADO.NET Data Services. In this article I’m going to show you how to implement your own ADO.NET Data Services proxy with T4 templates.
Source code and database backup
2. Content
2.1 Problem
ADO.NET Data Services is a very powerful toy, but as many other cool Microsoft technologies it needs some workarounds to become usable in the real world applications.
Most of the problems are connected with the auto generated proxy which is created after the addition of a service reference. Here are the most popular:
1. Data Contract objects do not support INotifyPropertyChanged which is needed for two way data binding.There are partial methods for detecting changes to specific properties which makes implementing the INotifyPropertyChanged interface possible, but not quick.
2. Add some common interface for all generated entites. (e.g. IIdentifyable)
3. Add custom attributes to properties of generated entities.
4. And many many others, which is caused by absence of control over the code generation process.
Uncontrolled code generation is a problem of all Microsoft ORM products, that is why community have created similar projects for LINQ to SQL (Damien Guard) and Entity Framework (Danny Simmons, ADO.NET team).
2.2 Solution
Solution to this problem is using of T4 templates for generation of ADO.NET data service proxy. In this case you will have absolute control over code generation process, so such task as implementing INotifyPropertyChanged interface will become trivial.
Mostly I was inspired by Damien Guard project T4 template for generating LINQ to SQL Data Context. It was my first experience with T4 templates, that’s why template helpers code may be a bit dirty.
