Using Ninject in a plugin like architecture

Question

I\'m learning DI, and made my first project recently.

In this project I\'ve implement the repository pattern. I have the interfaces and the concrete implementations.

Answer 1

you can easily do it with normal C# reflection, you don't need any extra technology.

There are quite a few examples on the web, e.g. http://www.codeproject.com/KB/cs/c__plugin_architecture.aspx

In general in your main application, you need to load the assembly implementing the plugin, e.g.:

ass = Assembly.Load(name);

and then you need to create an instance of your plugin. If you know the name of the class it would look like this:

ObjType = ass.GetType(typename);
IPlugin plugin = (IPlugin)Activator.CreateInstance(ObjType);

and then you just use it.

Answer 2

Take a look at Managed Extensibility Framework. http://www.codeplex.com/MEF

Answer 3

There are multiple ways to go about this and you already have accomplished the main goal to achieve this in having concrete implementations through pre-defined interfaces. Realistically, if your interfaces remain stable, you should be able to build off of your core application.

I am not sure how the implementation would work with Ninject, however. You can do this with the Provider Model or with reflection - although I think reflection is overkill, if you don't absolutely need to do it.

With the provider model approach, you place the file in the /bin folder, or any other folder that you are probing, and adjust the .config file to reflect the presence of the provider. If you have a specific "plugin" folder, you can create a method called at the startup of the application and periodically, otherwise, to scan for new or removed instances and reload the providers.

This would work in ASP.NET, under C# or VB. However, if you are doing some sort of other application, you would need to consider another approach. The provider is really just Microsoft's spin on the Strategy Pattern.