CODEWITHSUNDEEP
c#.netdependency-injectiontddinversion-of-control
Jon
Jon

Reputation: 40032

IOC in Winforms plugin architecture

I am working with an architecture that has a main program. When this starts it looks in the executing path via reflection for DLL's that have inherited off a base class. These are the plugins.

When a new requirement for a new project arises typically a new plugin is created. This plugin has the main plugin class and then possibly a number of other classes and windows forms.

The main plugin class has initialize methods but as its a class library there is no program.cs so to speak to wire up dependencies.

Is there a way via an app.config to wire up dependencies or do you think I should avoid using an IOC Container and just have a factory method in the plugin class that wires up the dependencies some how?

The issue is I may not have the ability to change the main application's code to setup the IOC container

Upvotes: 4

Views: 1789

Answers (2)

Bertie
Bertie

Reputation: 733

Whilst I think your question is a bit vague, based on what I gather from your question I would have to say IoC would most likely be the best way to go! You can use your IoC container to wire up the factories if you like, or you can use it to wire up the PlugIn dependencies, Personally, I like to use StructureMap. A very versatile and easy to use IoC container.

You could use the app.config to list the dependancy names and then feed the IoC the names to create dependencies. Use something like Activator to then create instances. Personally, I would use both IoC and factories. I would use the app.config to specify the dependency names and then use a Factory to dish out the instances of the plugIn classes. And finally I would then use the IoC container to specify the implementation of the factory(ies).

Hope that is of some use!

Upvotes: 1

Chris Shain
Chris Shain

Reputation: 51309

All major IoC containers have the ability to wire up dependencies with app.config or via an assembly discovery mechanism (like you describe). Typically the main application sets up the container, and then defers to the container to find the plugins (which may be configured via configuration or by assembly probing like you describe above).

For SpringFramework.net, as an example of app.config: http://www.springframework.net/doc-latest/reference/html/objects.html#d4e437

For Castle Windsor, an example of assembly probing: http://stw.castleproject.org/Windsor.Installers.ashx

Upvotes: 2

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