Add support for binding property to IConfiguration

[davidfowl]

In omnisharp I want to have a configuration like this:

{
   "msbuild": {
      "toolsVersion": "14.0",
       "properties": {
           "RandomProperty": "1",
           "VisualStudioVersion": "14.0"
        }
   }
}

I would like to express my options like so:

public class MSBuildOptions
{
     public string ToolsVersion { get; set; }
     public IConfiguration Properties { get; set; }
}

That way I would be able to express both the latebound and strongly typed properties on the same model object.

/cc @glennc @muratg @Eilon @lodejard

[Eilon]

This is like a combination of model binding and tag helpers 😄

We do support binding to dictionaries now with @victorhurdugaci 's change, no? Would that work here?

[davidfowl]

If I have a complex structure this gives me more flexibility

[Eilon]

True, but in the specific case you gave I think it's supported quite well. So, backlog?

[davidfowl]

Sure

[davidfowl]

Would it be Dictionary<string, string>?

[victorhurdugaci]

If you have only one level of nesting like in your example, Dictionary<string, string> will work. If you have multiple levels (e.g. VisualStudioVersion being a complex object), we don't support it that today and you have to use IConfiguration.

[Eilon]

I think it does all kinds of conversions for you... https://github.com/aspnet/Options/blob/dev/test/Microsoft.Framework.OptionsModel.Test/ConfigurationCollectionBindingTests.cs

It definitely seems to support Dictionary<string, string> though I'm not sure if TValue can be a simple type such as int, though I do see it can also be a complex type.

[victorhurdugaci]

Dictionary<string, T> is supported as long as all Ts are the same type. T can be int.

[Eilon]

Ah don't think I saw a test for that... did I miss it? If it's not there, can we quickly add one?

[victorhurdugaci]

Sure, I can add one tomorrow

[victorhurdugaci]

So, is this backlog or not?

[Eilon]

@davidfowl how passionate are you about this? For me this seems like super backlog. We can bring this back at any time.