Question

I’ve got a ConfigurationReader class that I’m trying to wire up using StructureMap or AutoFac (I haven’t settled on which container I’m using).

public class ConfigurationReader {
  private string _filePath;
  public ConfigurationReader(string filePath){
     this._filePath = filePath;
  }
   public IList<Baz> ListStuff(){
    //do something with _filePath;
   }

}

There will be 1..n to instances of this class based on how the app is configured (web.config will contain a delimited list of files). I’m looking for an extension point in either IoC container that would allow me to leverage them to create instances of ConfigurationReader.

Answer 1

Well, in AutoFac you can just register each one in the Container (during Application_Start for example).

Whenever you need to read all configurations you can add a dependency to IEnumerable<ConfigurationReader> (or IConfigurationReader if you decide to extract an interface) and it will provide you with all of them.

Something like this:

var builder = new ContainerBuilder();
foreach(var file in ConfigurationManager.AppSettings[yourKey].Split(',')) 
{
    var fileName = file;
    builder.Register(c => new ConfigurationReader(fileName));
}
DependencyResolver.SetResolver(new AutofacDependencyResolver(builder.Build()));

If you extract interfaces, then you may want to register by adding the .AsImplementedInterfaces() or .As<IConfigurationReader>() at end as well.