OptionsFactory.cs from https://github.com/aspnet/Options

OptionsFactory.cs

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System.Collections.Generic;

namespace Microsoft.Extensions.Options
{
    /// <summary>
    /// Implementation of IOptionsFactory.
    /// </summary>
    /// <typeparam name="TOptions">The type of options being requested.</typeparam>
    public class OptionsFactory<TOptions> : IOptionsFactory<TOptions> where TOptions : class, new()
    {
        private readonly IEnumerable<IConfigureOptions<TOptions>> _setups;
        private readonly IEnumerable<IPostConfigureOptions<TOptions>> _postConfigures;

        /// <summary>
        /// Initializes a new instance with the specified options configurations.
        /// </summary>
        /// <param name="setups">The configuration actions to run.</param>
        /// <param name="postConfigures">The initialization actions to run.</param>
        public OptionsFactory(IEnumerable<IConfigureOptions<TOptions>> setups, IEnumerable<IPostConfigureOptions<TOptions>> postConfigures)
        {
            _setups = setups;
            _postConfigures = postConfigures;
        }

        public TOptions Create(string name)
        {
            var options = new TOptions();
            foreach (var setup in _setups)
            {
                if (setup is IConfigureNamedOptions<TOptions> namedSetup)
                {
                    namedSetup.Configure(name, options);
                }
                else if (name == Options.DefaultName)
                {
                    setup.Configure(options);
                }
            }
            foreach (var post in _postConfigures)
            {
                post.PostConfigure(name, options);
            }
            return options;
        }
    }
}