Makes it easy to create a plugin-based architecture with Autofac.

Imagine you deploy an application with, say, a pipeline for transforming Maya binaries to some specific graphics-engine dependent format and another pipeline for transforming 3dsMax files to the same target format. You have a whole lot of types which have to be differently implemented in both pipelines, even though they stick to the same contracts. And you are using Autofac. So you need a way to easily tell the container:

• this is a component to be used in the context of the Maya pipeline
• this is a component to be used in the context of the 3dsMax pipeline
• this component X should be used by all pipelines
• for the Maya pipeline, please override X with Y

If this scenario sounds familiar to you, this Autofac.Extra is for you.

Install the nuget package Autofac.Extras.Plugins.

A short overview:

builder.RegisterType<GermanHelloWorld>().AsPlugin().Provide<IHelloWorld>("UniqueNameOfMyPlugin");

registers GermanHelloWorld as providing IHelloWorld in the context of UniqueNameOfMyPlugin.

builder.RegisterType<StandardFinisher>().AsPlugin().ProvideForAll<IFinisher>();

registers StandardFinisher as the default implementation of IFinisher for all plugins.

builder.RegisterType<GermanFinisher>().AsPlugin().Override<IFinisher>("UniqueNameOfMyOtherPlugin");

overrides the service IFinisher with GermanFinisher in the context of UniqueNameOfMyOtherPlugin.

For a complete example, see the src/Samples directory here at github.

Sometimes you will want to load plugins dynamically, that is, upon deployment of the main application you do not yet know which plugins will be available. In such a case you will need to tell Autofac which assemblies to load. For example, load all assemblies in a Plugins folder somewhere in your local user data. This functionality is not part of this extra, however. If you need this additional bit, you might wanna take a look at https://github.com/DenisBiondic/Autofac.Extras.ModuleDiscovery. Please note, however, that I have no first-hand experience with that package.

This package is governed by the Apache 2.0 license.