Converting IConfigurationSection to IOptions

Question

The Options pattern allowed me to create options objects containing values from configuration, as described here: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/options

I need the values for one option object within an IDesignTimeDbContextFactory implementation, to be used by EF when creating the models. (The values in that config section will be used for data seeding, and so I added IOptions to the DB Context constructor.)

As I have no access to IServiceCollection (since it's design time - like when running "dotnet ef migrations add", I need to have another way to convert an IConfigurationSection (representing the section I'm interested in) to my custom Options class.

May I know how I can do this without dependency injection?

Answer 1

You can use the Bind(Configuration, object) extension method to perform manual binding of any object. Here's an example:

var myCustomOptions = new MyCustomOptions();
myConfigurationSection.Bind(myCustomOptions);

// Use myCustomOptions directly.

To wrap this in an IOptions<T>, use Options.Create:

IOptions<MyCustomOptions> myOptions = Options.Create(myCustomOptions);

Answer 2

you can also use

config.Get<MyCustomOptions>()

This is an extension method from Microsoft.Extensions.Configuration namespace. I see it in Assembly Microsoft.Extensions.Configuration.Binder, Version=3.1.9.0. Perhaps, it exists in earlier versions also. That would give you the Settings object itself. then you can wrap it into IOptions as Krik showed in another answer.